Abbildungen der Seite
PDF
EPUB
[merged small][ocr errors][merged small]

which is not reedy in tone, not unequable in register, and is instantaneous in articulation, is a great musical boon. That any one, once accustomed to a Mason & Hamlin, would of his own free will go back to the harmonium, I cannot believe. Mr. Nash thinks that "for certain purposes " a person might even be beguiled back to the harmonium. I confess I can only imagine one such purpose, and that is, by contrast, to endear him still more to the beauty of the American organ. It is the old story of the part discords play in music; they make the harmony sweeter and more precious. EUSTACE HINTON JONES.

H. Jones can undertake to decide ex cathedra where so

your

that

[382] SIR,-I do not know on what footing Mr. E. many doctors disagree upon the respective merits of an harmonium proper and the harmonium improper yclept American organ. It was an old discussion in these columns, Mr. Editor, in the time of your predecessor, and in them the opinions of Dr. Ussher and of Dr. Leslie used to bear testimony to the super-excellence of the new instrument; but the flood of light let in upon the subject, and the experience resulting from many months' trial, have vastly modified at least one of these learned doctors' opinions. The other is capable of speaking for himself. In my humble opinion, it is rather unfair to your space thus to resuscitate the ghosts of hosts once slain; but at the risk of being tedious, I must join the ranks of last correspondent, Mr. Nash, in temperate and faithful defence of the cause of harmoniums Versus American organs. Now, I think though Mr. E. H. Jones's attack upon the harmonium is his strong point, that his defence of the American organ is his weak side, and this latter I will examine first. As you are aware, I am not insensible to, and I have before given expression to my appreciation of, what are the merits of the American organ, and it is needless that I should repeat here what I have before written on the subject, and which I find no cause to alter. But what is it that Mr. E. H. Jones can say in its favour? I have read and re-read his letter for the sake of being impartial, and if he finds my analysis correct, I fear that if he has paid 90 guineas for a No. 46 8-stop Breavington he will be obliged to reconsider the meritorious points of his instrument in order to write of it in a more eulogistic strain than pervades his first composition. The total of what Mr. Jones can say in its favour I will reproduce from his letter in a few words. First, he says, "the tone is round and pure;" "it is resonant; "it is pure;" "it is pure and true;" the intonation is perfect;" "it approaches the organ tone in quality." In addition, he claims that the touch is as rapid and as delicate as a pianoforte," but has no more enlogy for the quality of tone, nor for the variety of timbre which can be attained by means either of the reeds or their separate chambers, or their resonant sounding-box, or the exhaust bellows by which air is drawn through them; so that his communication sins more from faults of omission than commission, except his ungracions attack on the harmonium, the defence of which instrument is foreign to the purpose of my letter. Now, my opinion is very well made up on one point-that is, that you can neither expect nor produce from the reeds adopted in the American organ more than one timbre or quality of tone, and I gather from my own experience and from your correspondence columns that the great desideratum in reed instruments is variety of timbre, or, in other words, variety of voice.

value a rank of reeds of the quality of tone of the " pure
and true" description vaunted by Mr. Jones; but they
would not occupy a leading position in the instrument,
but be merely secondary, giving a little more variety of
voicing at the command of the performer, who seeks all
sorts. Not a few dislike the quality, considering them
as emasculated and squealing in the treble, although
sweet enough in the bass, as I have before borne my
testimony.
MARK ELLOR.

THE HARMONIUM.

[383] SIR,-Will Mr.Hermann Smith, "Eleve," the "H. B.," or any other fellow reader of the ENGLISH MECHANIC, help a poor man whose aspirations are larger than his means, by telling him what is the proper size for the bellows of an harmonium which is to have eight sets of reeds? Also, how much larger they must be if required to supply ten sets? It is intended to build the instrument with two manuals and pedals, so any information concerning matters of detail will be very acceptable.

shingle-we want resistance to enable us to utilize our muscular force. Treble reeds may be easily sounded without being enclosed, but bass reeds require a body of air to strike upon in order to render their slow stroke effective, else the air gets out of their way too soon. On the other hand it is of the utmost importance that the air should not suffer great compression, the reed cannot swing freely when the air particles crowd thickly upon it. The slow speech of the bass is chiefly owing to this, that the air is packed in a narrow wedge-like space trying to get through the reeds, yet pressed upon by the greater volume rushing from the wider end of the chamber, which exercises a dead lock pressure disabling the reed from striking. To remedy this, to gain a play of elasticity to aid the reed to vibration, we make an artificial outlet causing the air to yield, yet not allowing it to escape. Drill two holes through the side or end of the frame of the pan or sound-board, from 2in. to 4in. apart, and about in. diameter or less, if need be, but near the end where the bass reeds lie. Over these holes on the outside of the pan or sound-board glue a strip of soft sound leather from 6in. to 8in. long, and 2in. or 3in. wide, so adjusted that it shall form a pouch or cheek. In this pouch the overstress of wind expands itself, and the additional bulk of air stored in this reservoir affords its aid of elasticity to return and sustain the impetus of the reed.

It is

HERMANN SMITH.

The inquirer would be glad to be advised if it would be preferable to have two bellows, one for the reeds connected with the lower row of keys, and the other (with expression) for the reeds connected with the upper keys. Also, if it would be preferable to make the pans thicker at the bass end, so as to make the In suggesting to the reader a reference to back wind channels longer. Mr. H. Smith says that a reed numbers, I trust it will not be supposed that I am disfor 16ft. tone having a wind channel about half a yard inclined to the trouble of replying to new comers. long, yields the best tone, and possessing plenty of that a pleasure to me to give freely of whatever knowledge cheap article, wood (not in my head, I hope), and as II possess in the field in which I dig and delve. can use joiner's tools tolerably, I am quite willing to make the pans of any dimensions which will produce the most pleasing quality of sound. I do not, in the least, mind the labour of making the case of the instrument tall, wide, and deep enough to admit as large pans and bellows, or even two or three of the latter, if preferable, as may be considered best, so in any advice my fellow readers may be kind enough to give me they need not be restricted by consideration of the space which can be afforded for the instrument to stand in. I am well aware that I propose to construct what would be considered a large instrument, although not "Alexandre's" monster harmonium of the future, but then I have been accustomed to play on a large organ.

A POOR ORGANIST.

HARMONIUM.-REPLIES TO QUERIES.
[884] SIR,-New subscribers who are interested in
the harmonium would find their advantage in purchasing
the back numbers which contain my treatise. Ques-
tions they have asked, and many others which no doubt
will arise to puzzle them, have already been answered
in the progressive course of chapters explaining the
construction and theory of the instrument. I made
this reference to the past for the sake of those who do
not seem to be aware of what has been done in the
direction in which they are seeking information.*
"W. A. S." (4538, page 527) will find particulars
of sound-board construction in No. 116: also details
of sizes and scales of channels in my last chapter, in
No. 284, and of pallet and reed apertures in the forth-
coming chapter.

"A Young Amateur" (8998, page 287) is referred
to No. 109 for information concerning the "Full Organ
Movement," and its adjustinent.

J. T. Hill (4487, page 550) renews a question often asked before, and which I have more than once Seeing that every reed in an American organ is replied to, and also commented upon incidentally in the voiced in precisely the same manner, i.e., by having a course of the treatise in No. 133 and others; likewise little corner of its tongue curled up, it is forced to in letters. For his benefit I repeat the explanation speak in a manner a little less free than the ordinary of the defect he mentions as belonging to his own reed of an harmonium. This little disposition of instrument. The slowness of speech in the lowest tongue-tiedness, combined with due arrangement of octave of the bass may be caused by the reeds not being chamber and case, gives rise to that quality which is properly set or voiced; they may very probably be set its speciality; beyond it you cannot go, and every too high, and it is only when the force of the current of fresh rank only being permitted to speak, in this air becomes strong that they are drawn into move identical manner limits the capabilities of the instrument or vibration; they should, therefore, be pressed ment as to variety of voicing, and gives rise to that same- lower down that they will be set almost level with ness from which you easily escape in a well-voiced the block, the tip of the tongue rising perhaps 1-16in., harmonium. The little mechanical appliances of foot but the exact distance must be determined by experiswell and the little fan working as a tremblant consti- ment, as the character of the reed decides the treattute the only escape which the instrument offers from ment it should receive. If it is set too low, the reed is monotonous voicing, which, in course of time, will equally liable to sluggishness of speech, from an fall on the ear of the best-constituted musician. A opposite cause, there not being sufficient strength of little word as to the exhaust bellows. Will Mr. Jones current passing under or at sides of the tongue to draw say that he ever saw them in operation-that is, a pair the tongue with it, and the tongue acts as a door of bellows which, instead of sending the air through the shutting its own channel. For this reason the large chambers containing the reeds, actually creates a bass reeds are often reduced in width near their tips to Vacuum presumably below them through which air secure a constant space at the sides for the passage of rushes from above? If he ever did, will he please a current sufficient to throw the reed into action. describe the process? I am sceptical, and my reason There is another canse for the slowness of speech in for doubting is that positively there is no necessity for bass reeds of quite a different character-the shallow the process; the reed of the American organ being as ness of the body of air immediately under the reeds. easily blown forward in the ordinary plan of any har- The sound-board being thickest at the bass end there monium as the common concertina or harmonium reed. remains but very little space between it and the valve On this point I would beg the testimony of those board, in fact, very often under strong wind and ener English makers who are making American organs, getic playing the reeds will strike the valve-board. As notably Messrs. Cramer & Co., or any of your heavy swimmers require deep water to swim in, as talented correspondents who are au fait to the large birds find difficulty in rising until they get a mysteries of the trade. Excuse me enlarging, I was good depth of air under their wings, so in an analogous led into these remarks through the surprise expressed mode these bass reeds need a bulk of buoyant matter by Mr. Jones himself, that seeing the difference between under them before they can gain their full swing, they the one instrument and the other is so simple that no require the co-operating elasticity of a mass of air English maker should have originated it. clusion I do not want to expatiate on the merits of the It is as hard for bass reeds to get up speed in the open In con- to sustain and return the impulses of vibratory activity. harmonium per se except I have occasion, but I resent as it is for our legs to make progress over loose Mr. Jones's attack on it unless he had more to say in favour of the American organ. Are we not all agreed The papers were commenced in 9, and continued in that the American organ is simply an harmonium, in Nos.96, 98, 100, 105, 100, 116, 118, 124, 125, 132, 133, 136,141, style, in reed, in bellows, in case? I do not despair of 151, 159, 166, 172, 180, 190, all of which are to be had ex seeing added to any harmonium of sufficient size and cept No. 98.

CARBONIC ACID GAS AND OXYGEN.-TO "URBAN."

[385] SIR,-I am rather surprised to find the statement I made regarding the effects of carbonic acid so severely criticised by your learned correspondent "Urban" (343) p. 592. In the first place I would inform "Urban" that I am not an " Exhibitioner at the Royal College of Chemistry," as he has pleased to term me, and if he looks more carefully at the number he quotes from he will see his mistake. The contempt with which "Urban" speaks of little books, shows beyond doubt that he never stooped to read anything so elementary as to be contained in such diminutive nothings. I did not profess to quote the exact words of Professor Huxley, but for the edification of your correspondent take the following from page 113 of Huxley's "little book" on Elementary Physiology:

The directly poisonous effect of carbonic acid, on the other hand, has been very much exaggerated. A very large quantity (10 to 15 or 20 per cent.) may be contained in air, without producing any very serious immediate effect, if the quantity of oxygen be simultaneously increased." My use of the word proportion may be called in question as being indefinite, or at least to convey an idea different to the quotation made. "Urban" seems to have a wholesome dislike for indefinite statements, and this speaks well for his mathematical training; this being the case, I will endeavour to place before him in plain figures what I mean by increasing the oxygen in a like proportion. Take for example 100 litres of common air at 50 C. and 760 mean pressure; this air consists, in round numbers, of 21 parts by volume of oxygen to 79 parts of nitrogen. Now, suppose 20 litres of this air to be replaced by 20 litres of carbonic acid gas at the same temperature and pressure, x 20 4 1-5 is the amount of oxy

then

21 100

gen replaced by carbonic acid. To make good this loss of oxygen, we must remove 41-5 litres of nitrogen from the 100 litres of mixed gases, and introduce 4 1-5 litres of oxygen. In this way we have made carbonic acid take the place of an equal volume of nitrogen in the air, and assuming the non-poisonous nature of carbonic acid when in sinall quantities, there does not seem to be any reason to doubt the statement made by Huxley. For the sake of simplicity I have supposed the nitrogen removed, although it may not be practicable. I cannot imagine where "Urban" finds his thousands per cent. certainly I have not introduced anything of the kind in the foregoing calculation; perhaps while "Urban" enforces definite statements, it will be well for him to make his own a little less ambiguous. Would "Urban" be kind enough to inform your readers, myself included, whether the experiment has been made of breathing air in which the whole of the nitrogen was replaced by carbonic acid? I would expect the result to be the same as Dr. Taylor's case.

Since the function of breathing is in great part the removal of carbonic acid and water, to take in at each inspiration a quantity of the gas of which it is necessary to rid ourselves must necessitate an enormous amount of labour to be thrown on the organs connected with this function, and should these organs

prove unequal to the task death must ensue.

The statement that 4 per cent. of the gas did not produce any apparent effects on Dr. Smith is no doubt true, but he may be a strong, healthy man, and less susceptible than the majority of people. The condition of the lungs would very materially affect the question, and to establish a rule on one individual example ley's statements I have not to deal, but I may say would not, I think, be altogther advisable. With the ambiguity of certain of Professor Huxthat few men have done so much to advance the canse of true science as he has. His election as president of the British Association shows that he has the esteem of many of our greatest scientific men.

EXHILITIONER AT ROYAL COLLEGE OF SCIENCE.

BOAT BUILDING.

[386] SIR,-I send you a description, with illustrations, of a boat I made for myself, which is both swift and light. It weighs scarcely 50lb., and is easily carried from the water to its house. Procure two pieces of pine, in. thick by 3in. wide, which, when joined in the middle, make a keel 30ft. in length, Fig. 1. Set this upon its edge, and for about 5ft. at each end round it on the bottom, Fig. 2, to fit the skin, or outside of the boat. Make the braces, Fig. 3, şin. thick and of a width about 14in. in the widest part, tapering both ways, until no brace is required. Two braces are made different from these, of lin. thick, and of pine, see Fig. 4. The one nearest the bow, placed 18in. from the middle of the boat, the other about 30in. The depth of the boat and of these braces was about 5in., except at the ends of the boat, where they can taper to Sin. The two braces, Fig. 4, measured from A to B,

[blocks in formation]

5in., but from A up to C, 6in. Next procure some cedar plank, planed very thin; this cut into lengths to make the planking of the boat. It is sometimes bent on "whole," except at the ends, but not being an extraordinarily expert carpenter I did not attempt this, which is the method of the Thames and Tyne boat-builders. Break joints, from D to E, Fig. 5, two full lengths on both sides, the ends being pierced. Soak the cedar for about an hour, and in the mean time secure the keel firmly to some flat surface, keeping it down by a piece of wood, Fig. 6, nailed to the floor or bed. Place the braces in the positions they are to occupy, and get two pieces of yellow pine about 20ft. long, gin. thick, 2in. wide, and tapering to both ends. These must be rounded for about half the breadth on the outside, and be let into the braces and firmly secured to them and the keel, forming an even rounded bottom. Now put on the previously soaked cedar, bending it carefully to the shape, and fastening with brass screws or copper tacks. Cover the seams with thin sheet zinc or brass, fastening it with copper tacks; and clamp a piece of the same metal over each end to prevent breaking at the point. The boat is now complete except the top, the cockpit B, Fig. 5, seat, rowlocks or outriggers, and sculls. On the top of the braces, all around the boat, fasten a thin strip of wood, and on the braces, Fig. 4, let this strip fit into the shoulder, A. Then put on like strips edgewise, from G to C, and from H to C, gradually thinning to the ends, Fig. 5. Cover the whole of the top with waterproof cloth or linen, tacking it to those strips and to those round the edges of the boat. Cover the tackheads with a small bead. Now the boat is entirely closed in, except where the rower is to be seated. Let the sent be fastened to the keel, and to the sides by brass

Screws.

The cockpit is made by fitting the clapboards (or siding) around the braces, Fig. 4. At the end towards the bow fit two pieces to run out about 2ft. before meeting, like a V, and at the stern the pieces may be formed in a graceful scroll; but a piece about 2in. high should be fitted to the after brace of the cockpit to prevent the water coming in when "backing." The V piece at the bow should be so fitted as to form an acute angle with the forepart of the boat, as seen in Fig. 7. The irons, or outriggers, are 4ft. 6in. apart across the boat; and at their outsides, at bottom, about 14in. from the water. The irons are made as shown in Fig. 8, A being the rowlock with catgut fastened at the top to prevent the scull coming out.

Be careful in "turning," as you are liable to strain
the boat, to prevent which the planks were put in the
bottom, as well as to rest the feet on. It is as well to
wear loose boots or shoes, so that in the event of going
over you slip your feet out of your boots, which are apt
to stick fast when placed under the strap on the foot
board, A, Fig. 9. The V piece above mentioned should
be well secured down to the waterproof cloth. In fact,
it is as well to have pieces of wood underneath the
cloth and fastened through. A boat of this descrip-

[blocks in formation]

WHAT WE OWE TO THE ALCHEMISTS.
[387] SIR, The labours of the alchemists were popu-
larly supposed to be diabolical, and the popular legend of
the D- (something) and Dr. Faustus, is a not much
exaggerated exposition of the light in which popular
prejudice viewed their often useful works; but in this
case, as in many others, good came out of supposed
evil, and while trying to find the philosopher's stone
(his wooden block would often be much easier to find,
it being patent) the alchemists did find many
useful things. I may especially mention antimony,
which (however injurious to monks Paracelsus may
have found it to be daring his experiments on their
corpore vili) has been of great utility to us secular in-
dividuals, especially those of us who have the privilege of
dining at the Mansion House with the Lord Mayor, for
this indulgence creates a great demand for antimonial
wine to counteract the evil effects of certain other bad
wines then and there taken into the human stomach.
Another of the alchemists' discoveries, phosphorus,
has (although we make light of it) come into extensive
use during the writer's time. Those who, like him, can
remember the flint and steel of old, which, although
an admitted improvement on his ancestors' two fire-
sticks rubbed together, was what with knocked
kunckles, blunt-edged flints and damp tinder-one of the
torments of this life in the cold dark winter mornings,
-I say they will bless the discoverer of the fact that
much more light is to be got out of our bones than
some of our brains are able to yield. Phosphorus has
an evil reputation for poisoning those who work it, but
here Alchemy's legitimate daughter, Chemistry, steps
in and produces the perfect cure, or rather preventa
tive, in the form of amorphous phosphorus, which
surpasses poor human intelligence, inasmuch as it
affords "instantaneous light" (more than human in-
telligence often can do) without injury to health or
danger to property by accidental fire, for do not all its
matches " light only on the box "?

rods, whose weight is far greater than is t
genuine suspension wheel, to carry a ding A L
perhaps I may be mistaken in classing
sion wheels proper, for Mr. Tydeman say, Da
"quite slack."

Ön referring to my former communicate
seen that I expressed no doubt of the esc=
Phantom as a driving wheel for a lightly-bas
Sooth to say, there can be no doubt of
when we are told that it is of small diame.
with the Spider, and that it has thirty
3-16in. diameter. They must indeed be
-unless extremely slack-to transmit
force required to propel a bicycle even
hill. When it is considered that Smith and
No. 24 steel wire (pianoforte gange) has stu
pitch for more than two years, with a vibr
of 36in.-which fact I state on the author
Chew; that the said wire is only 1-20in, dissea
is equivalent to loading the said wire with in
about 800lb.); that the rods of the Phasc
are about 2-10in., i.e., four times the diame
24 wire; consequently, if made of equally gas de
capable of supporting sixteen times the ver
wire can sustain; that there are thirty-two
that at least ten of them, from their nearly a
position, are constantly helping to support t
of the rider,-I again say, when all these .
taken into consideration, that I believe any is
judge will admit that the thirty-two rods in the Fre
wheel have a tensile strength pretty consideran
excess of that required to suspend (I mean he writ
not himself) the very broadest of broad ebarchmen a
fact, assuming the average weight of the beaty
Christians who ride on bicycles to be foarten son
which is probably an excessive assumpte-hu
rods at least, always in action, would suspend at least
a score of such heavy-sterned Christians, who met
find it rather difficult to ride together az se brue,
for the same reason John Chinaman giờ và lự
evacuated his fortifications, viz., no te pure an
one place can be same time."

The number and weight of the thirty-y rods af a Phantom wheel being so enormously tons of the requirement of any weight which can be snel on a bicycle, we have a perfect right ye said wheel is made so much heavier than is need to support that weight. I have a very goa that I could indicate the reason its makets it; but of this anon.

as in the

In reply to Mr. Dawson, I never did say P wheels were not rigid enough for driving hem carras, whether they be made sufficiently so or not a naj Much as I am opposed to excessive governmental in- a question of the proportion of the lengths, the th terference with what is termed the liberty of the sub-nesses, and let me add, the degree of tension to VEŠ ject-a thing which often subjects other subjects to their steel rods are subjected. The rigidity of ther great liberties-when I consider how detrimental to rods increases, with increase of tension, ba health, and how incendiarily dangerous ordinary the more tension you subject them to the smaller the phosphorus matches are, I really think any govern- proportion of their tensile strength which remains a inent deserving the name of paternal would be justi- is available for supporting the weight carried; th fied in restricting the liberty of mischief in its subjects, however, is of little importance when, so far as to prohibit their production. This would, by Phantom, the material employed is so greatly in exces the mere saving of the present loss of property by fire, of that required to sustain the load. be a pecuniary gain to us, not to mention the saving of life which would result. Perhaps it is quite useless to advert to saving life, for it is quite obvious that so long as Christian peoples go to war with each other, any argument in favour of saving life would be quite lost on them, unless it took the form of saving the lives of their own military men to kill others; it might, however, have some influence on a neutral Briton like the writer, who don't want to kill anybody, and who also, having an eye to the main chance, might appreciate that reduction of the premiums on his fire insurance which would result. This argument comes home to his feelings-I mean his breeches' pocket-but it's all the

same.

An exceedingly interesting and instructive history of the various useful things discovered by those muchabused and misunderstood philosophers, the alchemists, might be written to advantage, and I do hope, even if you, Mr. Editor, cannot at present afford space for this history, that when the ENGLISH MECHANIC is enlarged eight pages (the doing of which is now a matter entirely in the hands of its readers), some one of my fellow correspondents, more fit than myself, will be found both able and willing to write it for the edification of his fellow readers,-may I add, also, for the edification of the readers of some other journals, which have occasionally been known to borrow the matter of the ENGLISH MECHANIC, sometimes with, oftener without, acknowledgment. Perhaps, like the American re-publishers of English literature, they forgot, or considered quite obsolete, that old-fashioned commandment, "Thou shalt not steal."

THE HARMONIOUS BLACKSMITH.

OTHERS.

Another piece of wood, shaped like Fig. 9, about lin. thick, must be cut so as to fit over the keel, and is secured by movable screws through the clapboards at the side, and by a little block of wood fastened to the bottom plank and the side of the keel. This is the footboard, and is made to shift to suit the length of SUSPENSION WHEELS: THE PHANTOM AND the rower's legs. It is as well to fit strips of sheet zinc where the heels come, to prevent the wearing of the plank. The boat must now be varnished, the inside of the cockpit as well. In fact, it is better to varnish the whole interior before putting on the waterproof cloth. A pair of light scnlls, well leathered at the button, and a small cushion staffed with horsehair will complete the equipment. I may as well mention that there is no necessity for the stem to be cut to the shape represented in the engraving, and the extreme ends of the keel should of course be bevelled off to a thin edge. When going out for the first row, get some one to hold the boat steady till you are seated, and with sculls in position. There is little danger of tipping over when in motion, but when resting don't let go of the sculls, as by keeping them under the water or on the surface you can balance your boat.

[ocr errors]

Mr. Tydeman says his Spider and the Phantom not to be considered one and the same." Quite tres Sharks and sprats are not exactly "one and same," but-I trust the reader will not deem my illa tration fishy in the evil sense-they most decidedly ha a common (piscatorial) nature, so also have these ts varieties of the suspension wheel a common natur, however different the proportions of the parts of each As in the instance of that menotonous musical (?) instru ment which is said to be employed in the region ceremonies of that little-known South African tribe, the Kanoodledums, the difference between the Spider ani the Phantom and the difference between the loag tom tom and the short tom-tom are only differences of pr portion, both toms are essentially tom-toms, bat wheels are essentially suspension wheels, unless, 1 deed, the excessively thick (and slack) rods of the Phantom act as veritable rigid spokes or levers, anda some extent remove it from the class of wheels whet support their loads on that principle.

May I just remind Mr. Tydeman I never assural that the employment of elastic spokes prevented the driving force from being transmitted to the the wheel? As well might I have said that wat weight is lifted by an elastic cord the hand ds.“ lift the whole of that weight. What I did say if the spokes be elastic levers you must bend the 20fore they can transmit the driving force, whic as true as that, in the case of the elastic cord, stretch it before it can lift the weight. I with pre add that I believe Mr. Tydeman's theory of the sa rubber tire to be perfectly correct, indeed it neces rially follows from the law that action and re-action are = each other. THE HARMONIOUS BLACKSMITH.

GERM DISEASES.

[388] SIR,-When adverting to a defect-for some purposes-common to all suspension wheels, viz., that their naves must to some (varying) extent be moved before their rims can be moved, which, by the way, is not a defect of much importance in bicycles and other carriages for light loads, I little thought what a nest of hornets (who have attempted to sting me) I should dis. turb; but as yet my rather pachydermatous cuticle is unconscious of their penetration,-like most of my fellow Britons, I don't know when I am whopped. Let me add that in writing abont suspension wheels generally, and the Phantom wheel in particular, I was actuated by no hostile feeling towards its makers. It may, for anything to the contrary I know, be by far fumed. the best wheel out, but it seems to me to have steel | In a hopeless case of putrid fever, where one patient

[389] SIR,-I am much pleased with Professor Tyndall's paper on filtered air and germ diseases in Nos. 263, 266. To destroy these germs and cause of disease:-In all places of closeness, bad smells, or contagion, secure an inlet of fresh air, and then generate pure nitric fumes from dry nitre and clean sulphuric acid aided by warmth. These fumes are diffused all over the room, and seizing all the moisture and germs, become visible as a slight fog. Fan or blow the fumes into every crevice and recess, and shake all clothing and bedding well in the fumes: every fresh article to be fumed before giving it to the patient, and every thing taken from him is to be

d just died, I recommended this process, and the othecary carried it through most admirably, and other patient began to mend the very day he introced it and gradually became well. This occurred soon after its promulgation by Dr. rmichael Smith, to whom the government gave ..000 for so doing. The doctor, though zealous for epublic good, was not chemist enough to see the erruling superiority of nitric acid fumes, for all the hers are hurtful to our lungs. The nitric acid and r atmosphere are of the same gases; nitrogen 4 to xygen; the acid 4 oxygen to 1 nitrogen; so when uch diluted they are not hurtful but are rather easant, and yet strong enough to destroy all congious matter, and so render it safe for nurses and

sitors.

CORNELIUS VARLEY. P.S.-If these materials were kept at all hospitals small parcels, quite ready for use when any patient rived, he might be fumigated, and also the conyance well fumed; this would remove all objections

[ocr errors]

the use of cabs.

HINTS TO CORRESPONDENTS.

[390] SIR,-In No. 281, you inserted a letter (190) on me on "Several Matters." Not having seen any of "Harmonious Blacksmith's" lucubrations since, .. has struck me that I might have offended him. I hope ot. I wanted to see him purify his style and not to cease writing altogether. I beg now to offer one or two more ints to correspondents. Every one, I should think, nust admire the orderly manner in which the contents of the ENGLISH MECHANIC are now arranged. I wish -hough that correspondents would attend to the simple instructions you have given under "Letters to the Editor." You say " in order to facilitate reference correspondents, when speaking of any letter previously inserted, will oblige by mentioning the number of the letter." If this rule were strictly adhered to time would frequently be saved by those who wish to refer to previously inserted correspondence. It would entail little or no additional labour on the writer, and confer a favour on the reader. There is another matter well worth attending to. As a rule the letters are answered by letters, and answers to queries appear in regular order in their proper department. But some correspondents answer a batch of queries in a letter. Take, for instance, Geo. E. Davis. In the number just received, 1. 881, p. 590, Mr. Davis answers no less than eleven queries. Now possibly some who asked the queries may look for the answers in their proper place and may not think or choose to look through the whole of the correspondence for

answers. It is the same with several other correspondents. See "W. E. D.," "Psi," and "Urban." In Mr. Davis's letter the names of the query with the numbers are given. It is not so with our able correspondent "Urban," or even with "F.R.A.S." These - gentlemen answer queries in connection with their pet sciences in letters; but how, let me ask, can their valuable answers be recorded in an index? And this is the point I am particularly driving at. A new subscriber turns over the pages of some back numbers and he sees just such a question as he should have sent himself. He refers to the corresponding number under "Answers to Queries " and it is not there, and he refers to the index and there is no record. If the answer had gone in according to the subscribed form no difficulty would have arisen. I am not finding fault -far from it. Doing the thing orderly would not entail more labour, and it would materially expedite reference. Let us all endeavour not only to extend the circulation of our ENGLISH MECHANIC, but to make it as useful as possible. SUBURBAN.

any,

SHORTHAND.

[391] SIR,-After reading the correspondence on shorthand in your valuable journal, most of your readers must be convinced that there is very little, if difference in actual practice between phonography and what Mr. Pitman calls the A B C systems of shorthand. The chief object of shorthand is brevity, and brevity is opposed to the correct representations of sounds. The word phonography, as applied to shorthand, is a misnomer. By shorthand I mean the power to write as fast as we speak. Mr. Pitman says (page 521), "In the use of the consonants we are tolerably consistent." It is on the consonants that all shorthand writers depend. The vowels are always omitted. No one more strenuously insists on their omission than Mr. Pitman. If they are omitted, what is the difference between phonography and the ABC systems? If they are introduced and the systems are "correctly written," why is one not as readable as the other? It is the omission of the vowels that gives rise to the difficulty experienced in reading shorthand. In most of the shorthand works published during the last 20 years, the authors have tried to remedy this defect by introducing the vowels in the line of writing-either written or implied. This is evident in "Sound Hand," by G. P. Renshaw; "Vowel Shorthand," by J. Rodam Carr; Thompson's "Phonography;" "Stenography," by A. Geiger; Shorthand for Everybody," by W. M. Williams; "Readable Shorthand," by Murdo Young; and "Universal Line Writing," by A. M. Bell. Some of these authors have been phonographers, and given it up on account of its complexity, and the extreme nicety and precision required in its notation. The in writing phonography may be imagined when you are told the alphabet contains forty letters, the straight lines having three sizes, thick and thin; the curves four sizes, thick and thin. Hooks of two sizes to signify the addition of 1, r, f, and the termination tion with loops and circles of two sizes for s str, &c. The system is written on a line,

[ocr errors]

care necessary

from the other.

real or supposed, in three positions-on, above, and below. There are three styles of writing; the learner's, corresponding, and the reporter's; each one differing In addition to this there are a vast number of signs, termed grammalogues, arbitrarily chosen to represent words of frequent occurrence. I use the word arbitrary because they follow no rule, and it is here that I take exception to the title "Phonography." It does not write by sound, because part of a word cannot be the whole of it. It depends for success on extreme abbreviation, taking care never to let one sign stand for more than one word. What is not simple is not possible. On this ground alone, Mr. Grierson, who so ably defends Lewis, has the advantage. It should be borne in mind that the acquisition of shorthand depends more on the individual than on the system. The late Charles Dickens was a facile and rapid writer of Mason's, better known as Gurney's, system, published in the 17th century, and having little simplest shorthand is one of immense difficulty, and merit to recommend it. The task of learning the can only be mastered by constant and unvarying practice. For all general purposes a system of abreviated writing, based on the common letters, combined with judicions abbreviation, would be found far easier of attainment, quite as effective, and more readable, because more familiar to the hand and to the eye. W. CANNABE.

[Want of space compels us to omit letters by "Pegasus," Geo. Stedhan, and "J. H. R.," on this subject. Each of these writers answers Mr. Grierson, and vindicates Mr. Pitman's system.-ED.]

TEA FOR THE MILLION.

[392] SIR,-Many of your subscribers may be glad to know that the raspberry-leaf-I mean the second ever tasted. The spring leaves are too strong. I have leaf (that now on the branches) makes the finest tea I used this tea myself for twelve months at a time withThe leaves, when out any fault being found with it. dry, should be infused just in the same manner as ordinary leaves. The garden raspberry will do, but I prefer the wild variety, which is very plentiful in the woods and dingles of England.

METEORIC STONES.

NAB.

[393] SIR,-The question of one of your correspondents ("D. W.") as to the composition and origin of meteorites is the more interesting from the knowledge we now possess, through the spectroscope, of the surface of the sun.

I have not had an opportunity of examining any of those meteoric stony masses, containing, as said, 6 per cent. of organic matter, of a kind of black mould of carbon, oxygen and hydrogen, somewhat like peat; but in my neighbourhood, on one of the Southdown chalk hills, the summit of which is capped with a patch of plastic clay, the metallic meteorites are found almost on the surface; the points and edges of the crystals being quite perfect. One of these masses, weighing about lb., encloses portion of an echinus. Near this locality is a gravel bed full of small fragments of this substance mixed with nickel are found meteoric iron much rolled. Quantities of in almost every strata down to the lias, if not lower. None of the portions found in the plastic clay influence the magnetic

needle.

[ocr errors]

As to their origin, a friend suggested some months ago that these metallic substances were the ashes or residuum of the gas seen in combustion around the sun; he was

the first who propounded this theory. It would account for the presence of these peculiar masses in so many strata of the earth; the same process going on at the earliest geological period as at present, the solid mass of metal falling, according to weight, the shallower or the deeper, into the semi-fluid strata.

Can that black kind of mould referred to above, be, after all, the black oxide of iron?

Laplace's opinion was that meteoric stones were projected from the moon into the confines of the earth's attraction, and consequently fell to the earth and became a part of it.

J. W. A.

THE SCREW PROPELLER AND ITS ACTION.

[394] SIR, The Rev. E. Kernan writing in your columns on "Elementary Science," has given a description of the screw propeller and its action, all of which is somewhat loose, but the paragraph referring to "Negative Slip" is especially incorrect.

He says

[ocr errors]

Negative Slip (the italics are his own) is when the vessel is going quicker than the pitch of the propeller requires, i.e., when the ship advances at each turn over a space greater than the pitch. Suppose the Great Eastern to advance 40ft. at each revolution of the screw (its pitch being previously stated at 37ft.) this state of things is called the Negative Slip.'" Now this explanation is literally very misleading and the meaning intended to be conveyed is quite erroneous. He continues-" And so far from being useful, the propeller is only retarding the progress. When, therefore, Negative Slip' is discovered it is time to stop engines, their action is sure waste." This is worse than incorrect, it is utter rubbish.

Then he adds-"It is evident that some external force, wind, current, &c., is able to do more just now for the ship than the propeller."

This also is quite wrong but it enables one to see that Mr. Kernan, writing on the subject not easy even to the professional mind, has at the outset quite misconceived the nature of the phenomenon he has endeavoured to describe.

The somewhat singular result known as the Negative slip of the screw propeller, is said to occur only when the excess of the vessel's speed over the speed theoretically due to it from the screw cannot be accounted for by "winds, currents, &c."

The effect of stopping the engines as recommended by Mr. Kernan would be to stop the ship also, and this plainly enough indicates that although the ship is advancing faster than the screw yet this advance is caused by the engine, although not directly, in the usual manner by the rotation of the screw.

The effect of a strong favourable wind on a screwship would be to assist the engines; and no doubt, if the wind were strong enough to force the ship ahead the screw would exert a retarding influence. But it is faster than the advance due to the rotation of her screw, not conceivable how a current could have any such effect. Nor would this advance be negative slip.

Mr. Kernan also mentions a peculiar arrangement of several boats driven by one steamboat. A system somewhat similar to this was I know tried on the Mersey some years since, but in this case the propelling barge was placed in front and drew the train of barges after it like a locomotive. In the arrangement Mr. Kernan illustrates the propelling barge is placed behind and pushes.

There can be no question as to which is the better arrangement, and I fancy Mr. Kernan alludes probably to the system I here mention. W. H. N.

MEDALLION TURNING.

and its Uses" of medallion turning, and I see there have been many inquiries of late in your paper on the subject, I herewith send you a photo. of my little machine for turning them. It will turn one in 20 minutes which any other machine will take 4 or 5 hours to do. If you think it would be a benefit to your readers, and particularly the amateur turners, you might insert it and the following, so that any amateur mechanic may make one for himself, as they can be applied to any lathe with two mandrels. A is a cast-iron stand on which all the slides, screws, wheels, pulleys, &c., are fixed; B is a small pulley which drives the wheels C from the back, D are screws driven by wheels C, E are two slides moved by screws D on slides, E are three levers that turn in conical centres and connected as

[395] SIR,-As there was no mention in "The Lathe

[graphic][merged small][merged small]

AN AMATEUR MICROSCOPICAL SOCIETY. [396] SIR,-With all due deference to "A. A. F." (342, p. 592) I cannot see the desirability of establishing another society when one already exists which is well able to meet the wants of those of our readers who are interested in microscopical science. Within the last few months frequent mention has been made in our journal of the "Quekett Microscopical Club," a society that now numbers 500 members, and which, for the small subscription of 10s., offers every advantage that one can desire. If "A. A. F." will refer to Vol. X., p. 241, he will get some insight into the practical working of the "Amateur's Friend;" or by applying to the secretary, 192, Piccadilly, he will soon learn that by enrolling himself as a member he will meet with every facility for prosecuting his favourite pursuit.

With reference to the inquiry of "E. L. G." (4615) as to the presence of fluorine in the human body, absence from home has prevented me sending a reply; the matter has, however, been so well gone into by three correspondents in this week's issue that it is unnecessary to say anything further upon the subject. BETA.

REPLIES TO QUERIES.

why such finings as isinglass or white of egg should
produce acidity. In my native village amid the
Chiltern Hills we never tapped our best ales until they
had been brewed eighteen months. Those of my
friends about Burton-on-Trent arrive at maturity in
fancy it Burgundy, and 'tis worth ten guineas a quart.'
as many weeks. It is attributed to the water. "Only

[397] SIR,-In reply to letter 342, in last issue of ENGLISH MECHANIC, I should like to remark that the society lately formed in Manchester, under the name of " English Mechanics' Scientific and Mechanical Society," entertains the features mentioned in that letter, so that it would not require a new society to be formed. The object of this, our society, being the in--BONIFACE. struction and mental recreation of its members by the [4299.]-SILVERING CLOCK DIALS (Unnoticed reading and discussion of papers on Scientific, Query).-Dissolve a piece of silver in dilute nitric acid Mechanical, and Literary subjects, as well as for pro- (two parts acid, one part water). When dissolved the moting exchange of opinions on interesting subjects. liquid will be a blue colour if manufactured silver is We are not restricted to make mechanical investiga- used, as it contains copper; now place in the solution a tions, as I believe is thought by many of your sub-piece of clean copper, when after a short time the silver scribers, but have, as will be seen from the above will be thrown down as a grey powder. When there is no more deposit allow to settle, then carefully pour off objects of the society, not excluded any scientific or interesting topic from our attention; therefore, I think the blue solution, and fill up with water so as to wash the powder from the acid, allow the powder to settle, "A. A. F.'s" suggestion for a separate society for then pour off as before. Repeat this two or three times, microscopical studies needless. so as to wash away every trace of acid, when the powder A. TOLHAUSEN, Sec. may be left to dry. Now mix together equal parts of cream of tartar and common salt. Thoroughly clean the article to be silvered with fine emery cloth or paper. dip a piece of clean rag (previously moistened with water) first in the cream of tartar mixture, then in the silver powder, and apply to the surface, rubbing until silvered. Be careful not to let the fingers touch the article, wash in water, dry, when the dial may be varnished. Mastic varnish diluted with about half its bulk of spirit answers very well. I have just silvered some articles by this means.-S. MOODY. P.S.-The following taken from p. 19, Vol. I., of the ENGLISH MECHANIC would no doubt answer equally well but I have not tried it :-Nitrate of silver, 30grs.; common salt, 30grs.; cream of tartar, 8 drs.; mix, moisten with water and apply. [4300.]-SAUSAGES (Unnoticed Query). For pork sausages, chop up fat and lean meat together, season with sage, pepper, salt, and allspice; 6oz. of bread crumbs to be chopped with 2lb. of meat. Fill skins Polonies are made of fat and lean pork, seasoned with salt, saltpetre, black pepper, and allspice. After standing several days with the above well rubbed in, cut small and mix with chopped shalot or garlic; fill oxguts that have been thoroughly cleansed by scouring, salting, and soaking; hang up to smoke; the gut should be tied at intervals of six or eight inches, or less, as thought desirable. Orford Sausages.-To a pound and a half of pork add the same quantity of veal, free from skin, &c.; three quarters of a pound of beef suet; then mix, and chop fine; add bread crumbs, season with dried sage, pepper,

In their answers, Correspondents are respectfully requested to mention in each instance the title and number of the query asked.

[3908.]-GRADUATION OF A CIRCLE.-On a strip of copper (tinned iron might answer) punch with a doubleended punch a number of holes, one in excess of division wanted; these must be punched by inserting one end of the punch, which should be rather larger than the other, into the previously-punched hole, and be in same straight line. The strip being thus prepared, turn down a circle of board to the size round which the strip will go tigat with the two end holes covering, through which a pin may secure the strip round the board, or the two end holes may be riveted, and the strip forced on tight and secured. This will form a division-plate for required circle.-SUFFOLK AMATEUR.

[3919.]-GALVANIC BAND (Unnoticed Query).-I can see no cause of failure in your correspondent's appliance or manufacture of the above. He must, however, only expect weak effect. I did not notice this query, or should not have allowed it to pass so long unanswered, and have been from home.-SUFFOLK AMATEUR.

[8949.]-GUAYANA.-Without admitting that Stieler, or any non-Iberian, is authority for Columbian names, I was certainly surprised at learning from J. G." that his atlas anywhere reproduced our Guy in this name. I find it does so in the small-world maps and the small South America, while the general map of both Americas has the full syllable Guay, and the detailed South America repeats it four times, always Guay. Moreover, his other authority (and that an Englishinan), “J. G.' himself quotes as beginning the natives' name with Guay and Wai! The fact is, that had men of our race discovered them, the spelling would unquestionably have been Wyanna. The doubled n would have insured the word against being made dactylic-if that is what "J. G." means by "short"-and the two letters Wy would, in English eyes, but no others in the world, have served for all that the Latin races mean by Guai, the G beginning this and scores of Spanish-American names by no stricter right than in the Latin forms of Walter and William. The native tongues throughout both Americas abounded in the syllables we (or cou-in Jonathan) express by Wa, Wha, Wy, and Why. These the Spaniards wrote Gua, Hua, Guai, and Haui, the G and H being regarded as a kind of opposites in matter

of aspiration, like the Greek 'and; but one or the other

being always required, in their eyes, to nail up the u to the following letters as one syllable, and give it that strong consonantal quality that our Gothic ancestors better indicated by enlarging it into W. It was for a like reason that they enlarged i, when it begins a sylla ble, into j; and between two other vowels doubled it, as j, to express that the former i merges into the previous syllable, while the latter becomes a semi-consonant beginning the next; and this ij, by losing its dots became y, as in this very name; so that, though neither is wrong the spelling with y (or ij) is more proper than with a single i. But the fact of our using single letters to express diphthongs, as in by, bite, Bute, a thing undreamt of in any other language; and that we might have expressed this syllable by Wy, can be no excusefor corrupting Guai into Gui or Guy, which not only every foreigner, but nine-tenths of Englishmen would be led to sound like the first syllable of Guido, Guyon, or even of Guienne or Guinea. With regard to climate, nobody fancies any country within 10 of the line, or even 30, is "healthy for Europeans," and the Colonial Guayanas are known to be signally the reverse. It was worth noting, therefore, that, on the other hand, Venezuela has less ill name on this score, and contains, perhaps, more European blood than any other intertropical country-certainly any under the 10 parallel. A friend, moreover, lately went on foot, alone, and without a tent, across the 400 miles of Calabozo plains, from Caracas to the capital of Guayana; fording or swimming the I do not suppose any such journey possible in the latter province itself, but should like to know in what other tropical continent the like has been

minor streams.

done?-E. L. G.

[4115.]-TROPICAL FIBRES.-I have just received the work about which "J. C. P." inquired several weeks ago-Tropical Fibres, &c.," by J. G. Squier. I was quite astonished in seeing that this book, advertized among "new ones" in a paper, was printed in 1863; it contains only 64 pages of print and 16 plates. These particulars may perhaps serve the querist.-BERNARDIN. [4210.]-SIGN WRITING (Unnoticed Query). — If "Brush Hand" will buy a long sabie-haired writing pencil and a book of ornamental alphabets and practise from them, noting well the form and manner of shading the letters, I cannot see but what he may soon be

master of the art of sign writing.-BLACKBURN.
[4291]-BREWING (Unnoticed Query).-Ales and
beers left alone require a considerable time to become
bright. If early maturity be required, I know no reason

that have been well cleansed.

and salt.

Beef Sausages are made in the same manner, but more highly seasoned with marjoram, thyme, and parsley. Saveloys are prepared of salt pork and beef, with onefourth part of bread crumbs, and a liberal allowance of spice, &c. Boil for half an hour.

Mutton Sausages.-Two-thirds of mutton to one-third of pork; the seasoning should be more delicate than used for beef sausages.

French Sausages. Take pork, which must have more fat than lean, chop fine; also parsley and chives, pepper salt, and spices; either put in skins, or make up into cakes and grill. Vary the flavour by adding trules or mushrooms, instead of chives. From MSS. recipes in an old family collection.

For trade purposes these recipes are often modified, by using oatmeal in large proportion, instead of bread crumbs, as pork sausages are now selling at from 6d. to is. 2d. per lb.-PATERFAMILIAS.

[4317.]-COLOURING SIZE.-Use patent white size, about 2d. per lb.; and common ultramarine, about 6d. per lb. The yellow tint of common size will affect blue, or any delicate colour.-DERFLA.

[4337.]-HOLLOW CANDLES.-I presume there is a glazed metal rod passed from top to bottom of each candle mould, with a hollow wick similar to that used for lamps, passed over it. When cold, the candle will draw out of the mould, and the rod out of the wick. The object is to brighten and spread the flame of the candle.

-DERFLA.

[4339.]-LA CROSSE (Unnoticed Query).--A short
illustrated article, giving directions as to the method
of playing the above game, appeared in the first weekly
part of Cassell's "Popular Educator" (new edition,
No. 1, Vol. I.), pp. 15, 16. Your correspondent may
obtain a copy of the above specified number through
any bookseller.-S. . . . R.
[4351.]-CASE FOR FERNS AND MOSS (Unnoticed
Query).-From 8in. to 12in. are good depths, ac-
cording to the description of plants for which the
case is intended. It is better to have an aperture
at bottom, which after the case has been planted
and well watered should be plugged up. The case
should be stout, of the best yellow deal, charring
it inside would be beneficial, but avoid metallic
linings. The "Fern Garden," by Shirley Hibberd,
contains many valuable suggestions and plans of
cases.-H. B. M.

[4872.]-OBOE (Unnoticed Query-
reply to "Anon's "`inquiry, I beg to say li
That a first-class reed for the oboe ges i
2s. 6d.. but as for the blowing the in
help him, as I am nearly fast with my
add that I think there are a good um.
country, but that very few are prajes
should much like one of our friends a
MECHANIC to give us a few practical leve
they would be much appreciated.—Je
[4485.)-TO "GASHOLDER.”—Th
by S. Highley, is dear I think for £10.
a gasholder made much cheaper.
size if required; the advantage is gre
your oxygen for days without spoiliza
than can be said for the bag plan, un
travel from place to place, you wo
holder too bulky.-OPERATOR.

if the curve is "ever egg-shaped, it mai u
[4504.]-ELLIPSES.-J. K. P.” surat A
symmetrical," but does not go so far as
than the ellipse, however long his una
E. L. G." (p. 595), that it is a ** more I
is not an "oval of the fourth order”
seen from its equation:

x = 2 R + a − 2 √/R? — gs — JER
where 9 a is length of connecting rod, sad !!..
of crank, and is no more complex the
section. "E. L. G." is a great deal to
T. W. Boord's mere sketch of a tamai.
gentleman is quite equal to self-defence.
ellipsograph is priced £2 to £4 in Holt rape.
and as mine, which is shown on p. det
the charm of novelty for E. L. G."")

double those amounts, according to size and the

[ocr errors]

a draughtsman, requiring to strike as CME
something cheaper is a desideratam.
will take the trouble to read my letter a p. cân, là v
perceive that I was at least then aware of the i
Symmetrical nature of the curve produced, we ? the
trouble of pointing out why one of the two co
there proposed has an advantage me be p
certain purposes; but I repeat that when the baby
connecting rod is five or six times that s
departure from the true figure is so slitta tomt Anta
perceptible, even when one oval is laid wer the u
and, I suppose, amply accurate enough ler
semi-ovals in isometrical drawing. I a
made on the connecting-rod prints, wat be
made to work accurately with
ditional in the way of mechaniek 4
now, taking the first part of "E. LV, DA
fault of the subject being recurred
those who set down to answer a questa
forward, but rather with the person WICK
referring to the back numbers. Also, the jar & Sonst
ellipses with a cord, even if accurate
fectly inadmissible on a drawing, theagreene
purpose of the gardener for staking out a foo
in which also so much accuracy is not looked #L-

J. K. P.

2

[4517.]-FISHING GUT may be stained vit ta coffee, or ink-and-water.-SUFFOLK ANATECE. referred to by "A Braider," is one sold by the W [4541]-EMBROIDERING MACHINE.-The ov & Gibbs Company. It makes a stitch like the We & Gibbs sewing machine, but the embroidery B. the upper side of the work, and the feed is controlle a small handle which enables the embroidery to be à in all directions without stopping or turning the w. The reel is on the under side, and the needle is sin to a crochet hook.-THOS. FLETCHER.

J. K. P." I might, with great trathfulness, bezin &` [4546.]-DIVISION PLATE.-In reply to remarks/ reply in the same words as those used in your impress of 2nd inst. by your worthy and very clever c spondent referred to, but as I recommended no parti numbers, and only gave such as my own experience a useful, and also as I referred to a printed is dividers by Baker, I will only explain, as tried a can, what to your aforesaid correspondent must very mysterious. My meaning of dicides into dif so is, that No. 720 has 15 divisors, viz., 2, 3, 4, 5, 6 12, 15, 16, 18, 20, 24, 36; 360 has only 14: so tha appears to be the greatest divider, and conse the most useful number of all the others. the Nos. 360, 144, 120, they will be found pl equally useful and necessary when J. K. P do fine work with poor eyes. I fear that the expeza of" J. K. P." in fine fluting, drilling, &c., is t equal to the attention I have at times to give, as I found every No. on my division plate come in lat for "J. K. P.," a copy of Baker's "Ready Bo which I request him to keep for reference; probably Mr. Baker may answer his interne "who ever had a circle of 720 on his dividias I have not, but all the other Nos. in Reckoner are on my Holtzapffel Rose Engis WAHSROF.

A fourth circle of 96, 11 se
I am

.

[4546.]-DIVISION PLATE OF LATHE -
will forward the address of "the chemical factory
[4361.1-METHYLATED SPIRIT.-If "T. L. H."nary ornamental turning, if the division plate
mits of three circles of holes, I should say that 1
where tinctures of all kinds are manufactured from and 112 would be found the best divisions; 180 m
by 2, 3, 4, 5, 6, 9, 10, and 12; 144 by 2, 3, 4, 6, 8, 9
and 112 by 2, 4, 7, and 8.
could be found for it, will often be useful.
lathe of Holtzapffel's containing the divisions re
mended by "Wahsrof," viz., 221 and 209, and during t
twenty-eight years I have been working with it, I
never once had occasion to use either of those dins
-G. C. C.

methylated spirit," to the Commissioners of Inland
Revenue, he will probably hear of something to his
advantage. By the act 29 and 30 Victoria, chapter 64,
section 8, it is enacted, that "No person shall use
methylated spirit or any derivative thereof in the manu-
facture, composition, or preparation of any article what-
soever capable of being used either wholly or partially
as a beverage or internally as a medicine," under a
penalty of £100 and forfeiture. The ninth section also
prohibits any alteration being made in "finish," except
by the addition of gum, resin, or colouring matter, under
a penalty of £200 and forfeiture. A copy of the above
sections was furnished to every chemist and druggist in
the United Kingdom upon the passing of the Act in
August, 1866. I leave T. L. H." to draw his own con-
clusion.-A REVENUE OFFICER.

[1367.)- RE-ENAMELLING CLOCK DIAL.-" Shef-
field Flood," p. 454, can re-enainel his clock dial by
grinding white lead with carriage varnish, apply it
with a brush, dry it in an oven with a gentle heat, and
polish with fine pumice. The figures are painted with
mastic varnish and lamp-black made thin with either
turpentine or oil of spike lavender.-J. M.

size he wants to make his enlargements, and it by s
[4555.]-PHOTOGRAPHY.-"Lex" must say to whe
or artificial light, then if the editor will spare me rrj
I will give him full instructions drawn from my ot
practice. To the second question I must say tha
would take a column of the MECHANIC to properly ans
it, but the formule I use is this, whites of egg sr
beaten by a machine for a sufficient time to convert the t
to froth, this is allowed to settle to a clear liquid, and
each gallon is added 800 grains of chloride of ammoniar
800 grains of chloride of barium, dissolved in 20 paper
of water, the two well mixed, poured in flat dishes, and
the plain paper floated on it, for from 15 seconds
three minutes, then dried in a room heated to 70. To
free the bath from acetic acid, pour into an evaporating

ish, evaporate to dryness, fuse the residue, dissolve in ter to 35 grains per ounce, filter and make just eutral or slightly acid, with nitric acid. The autotype axiting process is a method of printing in carbon by processes of Swan and Johnson, the patents are eld by a company who grant licenses to work the pros on payment of a small sum per year.-OPERATOR. [4556.)-TELEGRAPHY.-I am obliged to "Termial for his reply to my query under the above heading, must confess my eiror (through hasty drawing) in atting two wires on one insulator. I also thank "John eng," but "Terminal's" reply is undoubtedly right, as actricity in any shape would be as likely to strike the ire as the "guard."-Mus.

[ocr errors]

[1567] MATHEMATICAL INSTRUMENT 3- — S. tevens asks a question which week after week it has en my intention to ask, and although it is, so to nek, a wrinkle of trade, yet among the numerous ind-hearted contributors to the highly-valued ENGLISH LECHANIC, there are surely more than "J. K. P." who an find pleasure in offering advice and giving instrucon this subject, clear, explicit, and practical, Vithout doubt there are many besides, who will be very rateful to any skilled brother who will, in such a picit, reply to the following questions; or, in their ual way, describe how the work is put in hand and ione. The sort of "geer gathering "spirit, causes many our young folk to prize the heirloom instruments, which have a value in their estimation above even the ine finished foreign cases, but a bad or broken joint renlers them of no use; the will to mend it is consequently First, ften strong if the way to do it were known. hen, the joint-plates of drawing instruments, if steel, are so soft that they can be sawn out, or the brazing reelted and pulled out, or if worth while, a new joint n be made, and screwed or soldered lower down the LM-$Y - Second, after the plates are prepared is there a method of fixing them with cold solder or brazing, or is t always by heat? If it is please describe the kind of tarnace, fire, or blowpipe used, for there is such a risk of running down the solid metal, which is often only a stout wire of brass or white metal; and what solder is used? And last, while the file must shape, is the finishing done with it? I have heard that it is done on the lend lap," but how is that made, is it used dry or with oil? The finishing is clearly seen to be across the work and very plane and even, and the small projections or lists are all sharp cut, so much so that the sharpest edge or angle of a lead wheel, would seem unable to make them. How then is it done? A kind, practical, painstaking reply will be gratefully received by many amateur youths, who in the darkening evenings will rejoice in rying their hands at this interesting work under good nstructions, instead of being by failures and ignorance iscouraged from attempting to revive the appearance and usefulness of their old instruments.-S. H.

[1568.]-WEIGHT OF RAILS.-" Ferrum" scems to be able to easily ascertain the weight per yard of round, square, or flat bars of steel and iron, I suppose, by means of the usual tables. He asks a rule to find the weight per yard of rails of various sections (iron and steel); but how can he expect that can be furnished him unless the sectional area of each individual specified rail shown on the tracings is given? If such were the case, he could of course by the same tables, as easily as in the former instance, learn their weights per yard. A simple way to find the weight of any section of rail he may receive is to get a carpenter to make from the tracing a fall-sized model of the rail 6in. long; sink it in a quart of water, measure the displaced water, and check the Fine by measurement of the emptied space in the quart after the model has been taken out. Ascertaining thus the number of cubic inches in a length of 6in., he has only to multiply by six for a yard, and by the weight of a cubic inch of steel or iron to gain the desired weight per yard.-S. H.

[4572.]-GEOLOGICAL.-The limestone beds which are quarried on the west side of the Malvern Hills belong to the upper Silurian system, chiefly the Wenlock *cks of that formation. Should "Philosopher" require any further information I shall be glad to give it.-A. D.

MELVIN

(4539.)-TENDER FEET.-My plan is to wear shoes sufficiently roomy to admit an inner sole of cork or felt; tkick soles are preferable to thin ones on country roads. On arriving at night soak the feet in warm salt and water. Next morning bathe them in cold water and rub well with a hard brush. Forty years' experience have proved this practice to suit.-AN OLD MAN.

put on the right tack by various correspondents. I am
sure we should all be very glad if John James (4605,
replies to queries) would kindly give us some informa-
tion as to the construction of his model, if he does not
wish to keep his ideas private. If Mr. James could
meet me at any decent piece of water with his model,
I think I could convince him that it would not go at
double the speed of a sailing boat. W. HARROGATE.
[4616.]-PROBLEM.-In my last, I gave "Amicus"
the algebraical method of solving the statical problem.
The printer or myself made two immaterial blunders-at
least immaterial so far that the veriest tyro could tell
what was meant. Thus: in line 18, read ACD 185
not A CB; and in 4th line from the bottom read,
NIA +
= BD,

or,

لا

[ocr errors][merged small][merged small][merged small][merged small][merged small][ocr errors][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

1 No2

√2

10,000 = 586 2 (multiplied both sides by 1000) 10,000,0000 = 586 +2

[ocr errors][merged small][merged small][merged small]

=

which multiplied by the height 7, will give the solidity, i.e., 72 x -7854 x 7 78 x 7854 = the solidity of the cylinder, of which will be the solidity of the sphere. Therefore, 78 × 7854 × | = 73 x 5238 = the solidity of the ball.-J. NASH.

[4647.] PHOTOGRAPHIC.-If "Mendicus" was making a bath for negatives the rain-water will not do, he must add a few drops of a solution of carbonate of seda to the bath, just sufficent to cause a slight precipitate, shake well and put it in a clear white glass bottle, and expose to full sunshine for two or three days, then filter carefully, and add a drop or two of pure nitric acid suflicient to slightly redden blue litmus paper; if made of proper strength, 35 grains per ounce, it will work first-rate. The fact that the objects on the ground glass are reversed, will make no difference if he is taking negatives, the prints will be perfectly true to nature, it is owing to well-known optical laws, and not to any fault in the apparatus, as he seems to imagine. For- The third question is a rather difficult one to answer, as he gives me no data to guide me. Does the plate reremain quite clear after the developer has been on it a short time? if so it is owing most likely to too short an exposure, or a too acid bath; keep the bath so that it just turns the colour of litmus. If the plate turns black or brown as soon as the developer is applied it is owing to fog, perhaps from white light in the dark room. Prepare a plate and keep it in the dark room for about five minutes about 12in. from the window, then develop it: if it remains quite clear, and after #xing is as transparent as the glass itself, the fog is owing to light in the camera or dark slide. The remedy is obvious. If it fogs prepare a plate at night, using a candle about a yard from the plate to light the room, and develop as before; if it fogs, turn the bath out and proceed as directed for the bath made of rain-water. If that does not cure it he must ask again and send all particulars.-OPERATOR. [4647.] PHOTOGRAPHIC.-TO "MENDICUS."First, your mixing the bath with soft filtered water will not in all probability affect the working of it; try it, and if it should there is no remedy but to crystallize the nitrate of silver contained in the solution and redissolve it in distilled water. Second, if you had given your second query a thought, it would never have appeared in the MECHANIC; of course the objects are upside down, and right side to the left. Third, are you sure the plate is exposed properly by pulling up the door of the dark slide, and then taking the cap off the lens? or is the developer make according to formule.TOMETER.

x2 =1706484, &c. =180-6, &c., &c.
If the decimal places are carried further it will make a
slight difference in the answer. P.S.-I shall be glad
to solve a specimen example of such questions as can
be worked arithmetically, in order to benefit those
versity, if the editor will spare space.-C. H. W. B.
students prepaing for the Matriculation, London Uni-

[4616.]-PROBLEMS.-If I understand well, the pro-
blem is:-One angle of a rhombus is 135, corresponding
diagonal 100, to find the side. I observe that the sup-
plementary angle is 45, hence the side is the radius of
a circle circumscribed to an octagon, the side of which is
100; seveval tables give for that radius 130-7.-BER-

NARDIN.

[4624.]-PENDULUM SPRING.-TO “YOUNG JOB-
BER." Pallets and lever depths. The proper depth
for escape-wheel teeth on the pallets is, that they fall
just safely on the locking face of each pallet stone, on
no account must the depth be left shallower, because if
the teeth when escaping from either pallet fall on the
slope the guard pins will be driven upon the edge of
roller, by which the motion of the balance will be very
much impeded, and thereby prevent the watch keeping
any regular time; sometimes when the watch has a
strong mainspring it may stop through such shallow
locking, the guard-pin being forced against the edge
of roller, thereby stopping the balance. Of course when
set to the proper depth just named, the depth must be
transferred from the depth-tool to the upper plate for
marking off, and when uprighted in the frame the fol-
lowing is a sure method for trying these depths. The
wheel and pallets being in the frame, screw in the
balance with the roller on, having previously caused the
pallets to be end-bound, by placing upon the upper pivot
of the pallets' staff a thin piece of cork. Next lead the
balance round to allow the tooth of the escape-wheel to
fall on the pallet stone. The pallets' staff being end
bound ensures a good view as to the amount of depth the
tooth has upon the stone. If the wheel be deeper on the
pallets than I have named, the unlocking will be effected
with loss of power.
One thing must be always kept in
view, namely, that the wheel teeth lock just over the
rounded edge of the pallets' stones. Thus far the wheel
depth on the pallets. The lever depth upon the roller
and pin next follows. The roller-pin should have just
visible freedom in the lever notch, and at the inoment
of the wheel-teeth falling on the pallets-they being
kept stationary by the piece of cork just referred to-the
corner of the lever-notch should be presented to roller-
pin, and then when holding the balance firmly, at that
point of its motion, with a piece of peg move the lever
from side to side and observe what amount of motion it
has; if the same or a trille more than appeared when
trying the size of the roller-pin in the notch-that is a
good depth. If there be no shake till the balance is
moved onward, then the depth is too deep and the length
of the notch must be shortened. Always observing when
setting the roller-pin and notch-depths that just half
to state that the frame should be held in the left hand
the pin is embraced by the lever-notch. I have omitted
that with a nicely cut piece of peg force the escape-wheel
with the fore-finger upon the balance for leading it, and
onward. The remaining portion of “ Young Jobber's"
query respecting "the adjustment," that will be found
in my article in the British and Foreign Mechanic, Vol.
II., p. 84; subject-"The Watch: Its History, and How
to Repair it."-SECONDS' PRACTICAL WATCHMAKER.

[4590.]-TOWN GARDENING.-In the centre of
London, amongst smoke and dirt, occupying the upper
part of a house, with a broad staircase lighted from
love, I have, at about 10ft. from the skylight, arranged
around the walls the undermentioned plants, which live
and flourish luxuriantly:-Scarlet runner bean, Helio.
tropium Peruvianum, Scolopendrium vulgare (hart's tongue
lern), Blechnum spicant (hard fern), Athyrium filix
famina (female feru), Osmunda regalis (flowering fern),
Eremocarpus scaber, Nasturtium (varieties), Mimulus
moschatus,
Cobra scandens, Geraniums selected for
foliage rather than flower, Fuchsias various, Isolepis
gracilis, Convolvulus major, Lysimachia nummularia
(moneywort), Saxifraga Sarmentora mother of thou
sands), Vinca major (periwinkle), Tradescantia zebrina;
Lycopodium formosum, L. apodum, and L. denticulatum,
under bell-glasses. These plants cost in the streets and
markets from 1d. to 1s. each. The compost I use is
vegetable mould mixed with one-fourth part of fine
white sand; pots, well drained by potsherds, and bits of
charcoal. They are well supplied with water, in which [4630.]-COACH-PAINTING.-If an "Old Subscriber"
every fourth day is dissolved oz. of sulphate of will say what coach, carriage, or other conveyance it is that
ammonia to each gallon. The pots stand in porons red hehas to paint, I will do my best to give him all the
stands, from which the surplus water is drawn off by a information requisite, as there are almost as many ways
siphon. When any dirt appears on the leaves the plants of painting a coach, &c., as there are days in the year.
are carefully sponged. Such a utilization of a stair--BLACKBURN.
case might perhaps afford to others the same pleasure it
gives to-AN ATTIC WORKER.

[4595.]-HOUSES FROM STRAW, Erc.-In the Working Man, a paper published by Cassell, some two Years ago, there was inade mention of workmen's cottages Leing built of bundles of straw and some other material. believe they were building near Twickenham, about ten miles from London.-BLACKBURN. [4805.]-PROPELLING VESSEL BY WINDMILL. As I have misled Mr. Burton in the matter of the Lautical windmill, I am only too glad to see that he is this week

is

[4633.]-WEIGHT OF METALS.-I am sorry I had not time to reply to Ralph Williams before. To his first question I can only say that good works on mensuration generally contain a chapter on specific gravity, which is what he wants. Hutton's "Mensuration published by Longmans, London, and others; its price I don't know; I bought it second-hand. In reply to the other question, solid geometry proves that its sphere is of its circumscribed cylinder. Of this cylinder the diameter and height are equal, in this case 7in. Therefore, 7 x7854 will give the area of the base,

[4647.]-PHOTOGRAPHIC.-The effect of "Mendicus" having dissolved his nitrate of silver in soft water would be that it would fog plates if in a negative bath, and in a positive would render the paper mealy. Notwithstanding, if he treats the bath in the same way as I suggested a dirty bath should be in two or three numbers ago, it will be equal to one made with distilled water. Second, the image that he sees on his screen is from the lens, and being inverted it is of course reversed. of course inverted on account of its being a "reflection" The only remedy for it is to carry out the suggestion of a humourous photographer, i.e. turn your landscape upside down, and make your sitters stand on their heads. Third, the causes of no image appearing on application of the developer are many insensitiveness, weak developer, under-exposure, too much acid and not enough patience. If" Mendicus" can get the back numwill not find it a waste of money,-on the contrary. But bers from December last, he will find all my formulae. He if he does not feel disposed to do so I will look back and let him know in what Nos. the formule appeared. "Menhe had better look to his lens and camera to see that dicus" cannot help getting an image with it. If he fail the old gentleman "is not in them.-Mus.

the

[4648.-COINS.-The first coin engraved is a silver penny of William I. Inscription on the obverse," Pillelm Rex," signifying William King; reverse, "Ogmund on Sude," signifying it was struck by Osmund of Southwark; worth about 58. The second coin is a sixpence of Philip and Mary, Inscription, Philip et Maria, A.D.G.R. Ang. Fr. Neap. Pr. Hisp.," signifying Philip and Mary, by the Grace of God Queen of England, France, Naples, and Princess of Spain; reverse, shield of arins, with the inscription "Posvimus Deun Adivtorum Nostrum." The numerals VI at the top of the shield mean the value (sixpence); worth about 8s.-W. J. EGGLESTON.

[4618.]-TWO COINS.-No. 1, Penny of William I.; No. 2, sixpence of Philip and Mary.-BERNARDIN.

[4648.]-TWO COINS.-The first is a silver penny of William I. or II. Obverse: full-face bust of the Conqueror, holding a sceptre in his right hand. Legend, PILLELM REX (William, King). Reverse: a cross, with the letters P. A. X. S. in the angles: Legend, OSMVND ON SUDE (Osmund at Southwark). The name of the moneyer and place of mintage. Common value, 2s. to 5s. The second coin is a sixpence of the second issue It is rather scarce; of Philip and Mary, coined in 1554. value about 10s. For full accounts of these two coins see my "Guide to English Coins," Part II., pp. 15 and 67.HENRY W. HENFREY, M.N.S., &C., &C.

[4650.]-FRENCH LANGUAGE.-The best work I

know is Havet's" Complete Class Book," Parts I. and II., Parts I. and II., are very good, and will well repay carepublished by Simpkin & Co. Cassell's" Lessons in French, ful study. Much more, however, depends upon continuous perseverance than upon the text-book. **Don't try to learn French in six months."-A. POCKLINGTON.

[4650.]-FRENCH LANGUAGE.-I have learnt very successfully from the two following:-" The Beginner's Own French Book," 28.; key to the saine, 28.; by Delille. Should "Patty" wish to acquire a superior knowledge of the language he cannot do better than obtain the following in rotation:-" Easy French Poetry for Beginners," 2s.; "French Grammar," 5s. 6d.; key to same 28.; "Modeles de Poesie," 6s.; Repertoire des Frosateurs Français," 6s. 6d.; "Manuel Etymologique," 2s. 6d. ; the whole comprising Delille's series, which is pronounced by the leading professors as the best.PIRO.

[4651.]-POWER OF WATER-WHEEL.-The rule for this is as follows:-Raise the radius of the wheel to the third power, and extract the square root of this power; multiply this root by the area of the transverse section of the stream which supplies the buckets; divide the product by 65, and the quotient will be the mechanical effect in horse powers:

« ZurückWeiter »