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successfully performed under favourable conditions; but in effect he admits that, whatever may be the conditions, the success or failure of the experiment is dependent upon the merest chance, for he adopts nearly the same argument as was used by Mr. George Shepherd, an English weather forecaster, to account for the fact that no dependence whatever could be placed upon his forecasts. "But," says Mr. Le Maout, "if it does not rain upon us when we fire the cannon, or when we ring, it may rain somewhere else, especially when the sky is charged with rain-cloud within the area affected by the

sonorous body. Thus, not only may rain fall in

the neighbouring village, but even at immense distances, since in the great disturbances of the aerial mass by the formidable discharges of artillery at the siege of Sebastopol it often rained here (in Brittany) although not a drop fell in the Crimea." From this it would appear that our great pharmacist is not so much in want of correct premises as of ability to deal with them; but it is precisely this latter want that gives us the amusing absurdities he has treated us to. Often, he continues, the firing of the cannon and the sound of the bells clear the cloudy sky, and send the threatened storm afar.

Similar effects were observed, not only during the Crimean war, but during that of Italy, and of the Austrians and Prussians; and he observes that storms were more frequent than usual during those events. In confirmation of his views he reminds old military officers that at the siege of Antwerp the besieged were constantly under torrents of rain, and up to the knees in mud, but that as soon as the citadel was taken the rain ceased, and the weather became fine. They will remember, too, the memorable storm of hail, rain, and wind which occurred before four and five o'clock in the evening on the battle-field of Solferino, which alone put an end to the fury of the combatants, and saved the remnants of the Austrian army. In that case the physical force was accumulated by the powerful means used, which had the effect of concentrating the hurricane upon the battle-field itself, the battle acting incessantly like a suction pump. He accounts for the storm at Puebla and the nonsuccess of French arms in Mexico in a similar manner, and it seems that even England may well be thankful that M. Le Maout's doctrine was not accepted half a century earlier. The success of England in some of her greatest conflicts with foreign nations has frequently been attributed to her knowledge of war and water; and (in another sense it is true) Mr. Le Maont attributes the loss of Waterloo by the French to the want of that knowledge. If, he observes, Napoleon I. had known this condensing power of cannon, which, by the way, he could better than any one else have observed upon so many fields of battle, he would not have undertaken, upon June 16th and 17th (the eve of Waterloo and day previous), the battle of Ligny, and the engagement with the rearguard of Genappes, during which a storm occurred, commencing about three o'clock in the afternoon, and continuing for twelve consecutive hours to pour down torrents of water, which converted the ground into a perfect marsh, alike impracticable to man and beast. It was the twenty-four rounds fired on the retreating English columns that, in Mr. Le Maout's opinion, brought down the rain, and prevented the movement of the French troops until the following day, by which time the Prussians had arrived; hence the loss to the French of the battle of Waterloo.

opinion, reason to believe that if the condensation
cannons, which act like a suction pump, were kept
in energetic motion on the English Channel, the
vapour of water would flow there and fall as rain,
not only from the west, but from the Mediterranean
and the Northern ocean. Is this to be accepted as a
result of superior technical education on the
Continent ?-E. D. H., in the Scientific Review.

AS

HINTS ON WATERING PLANTS.

if they are too large, they contain more
than can be absorbed by the plant while it is sweet
and, if too small, will not contain enough.

I am afraid your readers will think I give the
credit for very little knowledge, but it is beca
I know that a very large proportion are expe
cultivators, that I can speak so plainly for L
advice of beginners. But just another mom
while I place two or three guards aromd
practice I have been advocating. Let everyth
placed in pans be well potted, sufficiently dres
and filled with roots, and for innumerable subject
such as roses in pots, vines in pots, orchard-tres
fuchsias, and strong-growing and free-rooting thisp
generally, this will be found a most satisfact
provision.-By WILLIAM CHITTY, in the F
World.

THE EVAPORATION METER FOR

BOILERS.

(Illustrated on page 492.) RIALS made at different times of

SI have a good deal to do in various ways with amateur gardeners, I have frequently opportunities of noticing their shortcomings in a variety of particulars. In ninety-nine cases out of a hundred almost, ladies and gentlemen who are excessively fond of flowers, have a little plot of garden, perhaps a greenhouse and a frame or two, and bestow a good deal of time, money, and pains, do not realize the results they think they have a right to expect as the reward of their application. I think we may place some portion of the failure to the account of the want of tact, which Johnson defines to be "expertness and skill in the management of any affair; Tive effect of different construction fir ready talent." Let something more go down to the and different kinds of fuel have shown co lack of untiring vigilance, indomitable application. variations in the relative amounts of s One single neglect of some particular item in the duced. The cause of these variations may bad routine of management will sometimes render for-first, in the construction of the boilere nugatory a whole year's attention. If the clock dis-setting; second, in the quality of the fnd; continues its ticking, notwithstanding the monotony in the qualification of the fireman. of the process, family and business arrangements are thrown into confusion. Then, again, observation quite justifies me in saying that, in very many cases, sour mould, injudicious mixture of soil, bad potting, and imperfect drainage, completely block up the way to success. But the one great hindrance, on which I purpose for a moment or two to dwell, is injudicious watering. To be plain, there is no rule that can be laid down for watering plants in pots. Some persons ask, "Should not plants in pots be watered every day?" The answer is, Every collection of plants in pots should be looked over every day, and those that are dry should be watered promptly and sufficiently." Let me explain what I mean by "sufficiently." When a plant is potted, there is a space between the surface of the mould in the pot and the margin of the pot; this is to hold the water necessary for the plant growing in the pot; if the space is pretty deep-say in., or an inch-this space quite filled up with water will generally be enough for one dose. If the space is shallower, and the 'plant is very dry, it may be filled up two or three times, as the case may be, until the ball is thoroughly moistened. If the ball has got so dry that the earth has shrunk away from the sides of the pot, and the water when poured in runs away between the ball and the pot without penetrating among the roots, after the first dose has been given, draw the finger all round the opening on the top of the soil. This operation, simple as it is, will detach mould enough to fill up the gap, and the water which is afterwards given will, instead of running away uselessly, permeate the entire mass of soil in the pot. And let it be remembered that this "sufficient" watering applies to winter as well as summer treatment; it is a mistake to give plants in pots that are dry only water enough to moisten the surface of the soil. Subjects that in the summer require copious supplies of water every day, in the winter, perhaps, will not want it more than once a week; but when they do have it, give them enough. I would also persuade amateur gardeners to adopt feeders, or saucers, or pans, or whatever may be the name by which they are locally designated; these will be found to be of incalculable advantage to many plants; not the glazed pans, but those of the same material and finish as the common garden pot. First of all, the water which has passed through a pot of soil that has become dry will be retained by the saucer, and will be absorbed by degrees, according to the necessities of the plant. Then, again, the pan itself absorbs a considerable quantity of the water, and furnishes a moist, cool bottom for the plant to stand upon, most grateful to plants of all kinds, and analogous to standing on a bed of ashes or sand out of doors, where they are always found to enjoy themselves. Further, there are numbers of plants that positively delight to stand in water. Fuchsias, all through the growing and flowering season, begonias, arums, callas, ixias, many ferns, and other things, will amply repay by their luxuriant vigour the indulgence of being permitted to stand in a pan of water.

The fuel for steam boilers forms such a item in the expense account that it is certain the greatest importance to owners of boilers make themselves familiar with the proportic which the production of steam stands to the quare of coal used, and to reduce the latter, if possible.

Official trials of the evaporative effect of d ferent construction of boilers, and different qualitie of coal, give important information; bat attentive ness and skill of the fireman, a very important factor in the saving of fuel, cannot be tested by single trials, but only by continual watching, and increased only by introducing a system of wages. which depends upon the amount of coal saved. The important results obtained by the latter system is clearly proven by the fact that since its introduction in the case of locomotives, an average saving of fuel of over ten per cent. has been obtained thereby.

On railroads the record of each locomotive is made up from notes of the freight carried, and the distance travelled. The differences in the grades of the road are regulated by coefficients.

It is difficult to determine whether Mr. Le Maout is the more worthy of admiration as a philosopher or as an historian; but as we are not called upon to give a decision, the question may consequently be left to our readers. We will content ourselves with explaining how the great discovery is to be turned to practical use, by recording a statement of the conditions which he regards as most favourable to success. The instructions are given for St. Brieuc, so that experimenters will have to make the necessary corrections for locality if applied elsewhere. Make the experiment with the wind blowing from the south-west and carrying heavy rain-clouds, and choose a day when the barometrical pressure averages less than 76 centimetres. Commence in the morning, before the misty bank formed on the surface of the English Channel is dispersed by the rays of the sun. The lower the temperature the better. Proceed by simultaneous explosions from one or several batteries every quarter of an hour. Upon this day all military target practice should be suspended; and if the experiment be made upon the day of a religious feast, when the bells are rung, the probability of success Again, it will be a great relief to many an anxious will be all the greater. If the experiment succeed, cultivator who leaves his home in the morning, and it be judged that sufficient rain has fallen, and as he takes a last look at his potted plants, transport the condensation cannons from Cherbourg to feel sure that, by leaving them a supply of to Brest, and fire again to stop the current of water within their own reach, their necessities vapours coming from the ocean by condensing them will be met through the length, it may be, of a in their passage. Thus, to have rain, fire at Cher- long, bright, parching summer's day, to find at bourg on the rainy winds of the south-west; to have his return home, after the toils of business, that dry weather, fire at Brest on the easterly winds his plants are not only not perishing from drought, which reach there after having traversed Central but are, perhaps, considerably improved in vigour Europe, and been deprived of their vapour of water and beauty. Only once more let me say that, in by the numerous bells in Christian churches and using pans, adapt them to the size of the pots-that the noise of inilitary exercises which they have met is, let 48-size pans be used for 48-size pots, and with on their way. There is, in Mr. Le Maout's the same with other sizes, as it will be found that,

With boilers for stationary purposes, such system of control cannot be employed, for t kind of effect is generally variable, and a true na sure for them does not exist. Moreover, the m effect is dependent not only upon the engines fireman, but also on every workman ope machine. A more direct index of the eng the fireman is the exact measure of the duced. At different times attempts have be made to determine this point, by passing the wa fed to the boiler, through a meter. Most of meters have been condemned on account of the want of accuracy and durability. All water-nstes however, are not adapted to steam boilers, as the do not note the temperature of the feedThe chief point is not to ascertain the quantity d the water evaporated, but to establish the s of heat applied to the boiler by the combustion & the fuel. The ratio of the quantity of heat ma useful to the amount contained in the fuel forms the basis for estimating the efficiency of the man, and the perfection of the boiler constracte The feed-water offers the means for measuring effective quantity of the heat, but it is not suffics to measure its quantity alone-the temperator which it enters the boiler must also be care considered.

In trials of short duration, the temperatures feed water can be noted and entered in the tion, but in practice this can not be done w object in view is not one short trial, but ti tinuous observation which is necessary for se plete control of the fireman.

The evaporation meter, which we here prese answers every demand. It is not damaged by be water, the measurements are correct, and tr cords the temperature of the water entering i boiler, so that on its index-dial the quantity of be made effective may be read off in heat units. I will be seen on examining the annexed cut, that th water which enters the apparatus rises upware through the channel B, and falls on the cascade C over which it flows slowly downwards. By the means the feed-water comes in direct contact w the steam of the boiler, which has free access to the interior of the apparatus through the pipe I The feed-water is thereby heated to the tes perature of the steam, and falls with the condensing water into the box E. It then enters through the passage F, the drum G, which contain six helix-shaped compartments. The drum is closed on one side, except the central opening, throug which enters the passage F, and is open on the other side. The lower part of the drum is immerse in the semi-cylindrical basin H, the upper edge, J, of which is below the lower edge of the passage F

The entering feed-water fills the compartments, and thereby causes the drum to revolve. The number of the revolutions of the drum is exactly proportionate to the quantity of water passing through. To reduce the friction in the journals as much as possible, the shaft of the drum rests on its two ends, at O and N, on friction rollers. The water passing out at the open end of the drum falls over the edge J, into the steam boiler. The revolutions of the drum are transmitted to the shaft L, arranged with conical packing, passing through cover K, and operating a counting apparatus, placed outside the steam-room. A small air-cock on top of the upper cover serves to permit the escape of the atmospheric air brought over by the feed-water.

As one of the merits of this apparatus we may mention that it is constructed without any packing. Moreover, the drum effects the measuring with such accuracy that it excels in this respect any other water meter, and this accuracy is not influenced in the least by impurities carried along by the feed water. The formation of scale will disturb the action of this apparatus much less than any other known water meter, there being, as already stated, no packing whatever, and all the cross sections being very large. The registering apparatus is entirely removed from the influence of water and steam. The basin with the drum, as well as the cascade, can easily be taken out and cleaned from scale either by the hammer or by treating it with <liluted muriatic acid.

Another great disadvantage of other water meters is that in the case of interruption in their functions the feed of the boiler is entirely stopped; such a case cannot happen with the evaporation meter described above.-Dingler's Polytechnisches

Journal.

T

SCIENTIFIC SOCIETIES.

the

for his interesting essay, and the following questions,
forwarded by members, were proposed for consideration
at the next meeting.

I. Give an explanation of the action of the ejector
condenser, with a sketch.

II. Information required on Clayton's patent scraper, as used with the fuel economizer.

III. Any member's experience of the Birmingham patent safe and sure sectional wrought-iron boiler; how it is for steam-room, for comparative consumption of coal, and any practical information thereon.

LETTERS TO THE EDITOR.

[We do not hold ourselves responsible for the opinions
of our correspondents.
The EDITOR respectfully
requests that all communications should be drawn
up as briefly as possible.]

All communications should be addressed to the
EDITOR of the ENGLISH MECHANIC, 31, Tavistock-
street, Covent Garden, W.C.

I have very little to say to Mr. Firth, p. 450. I will not be answerable for press errors, which I have no opportunity of correcting, and therefore he must fight out his 4h. 32m. and 3h. 32. with your compositor. I, however, plead guilty to a lapsus calami in writing 28ht for 27th.

I have not discontinued-at all events permanentlygiving "the times of rising and setting of some of the planets," as Mr. F. may see in the very number in which his own letter appears.

His third paragraph seems, to my obtuse perception, to be a remarkably successful imitation of utter nonsense. Suppose that I say that a certain superb instrument is situated in latitude 51° 28′ 38 N., and longitude Oh. Om. Os., and that it is consequently in the transit circle room of the Royal Observatory at Greenwich. I wonder whether it must be acknowledged by all" that "the inference or deduction is illogical ?"

All Cheques and Post Office Orders to be made pay- took these " able to J. PASSMORE EDWARDS.

"I would have every one write what he knows, and as much as he knows, but no more; and that not in this only, but in all other subjects: For such a person may have some particular knowledge and experience of the nature of such a person or such a fountain, that as to other things, knows no more than what everybody does, and yet to keep a clutter with this little pittance of his, will undertake to write the whole body of physicks: a vice from whence great inconveniences derive their original."-Montaigne's Essays.

In order to facilitate reference, correspondents when speaking of any Letter previously inserted will oblige by mentioning the number of the Letter, as well as the page on which it appears.

SOME OF MY CRITICS.

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[189] SIR,-At the risk of bringing down the wrath
of Mr. Brandon on my head, I am strongly tempted (with
your permission) to say a few words to a couple of
gentlemen who have honoured me by criticising some
of my more recent dicta in your columns.
And firstly, Mr. Usborne (140), p. 458, is indeed "a
bold man, "taking up the cudgels as he does, not
against the present writer-who is, goodness knows, a
sufficiently humble person-but against a most per-
fectly ascertained and well-known law of motion. It is
as though a man should take credit for pluck in de-
scribing me as a bad arithemetician (which he might
or might not have a distinct right to do), but who, all
the while, was merely proclaiming that two and two
by no means made four. Is it possible that Mr. U.
has never heard of the composition of forces?

CONFERENCE OF MECHANICAL ENGINEERS.
THE annual conference of the mechanical engi
neers of England commenced at Nottingham
on Tuesday.
There was a numerous attendance, in-
cluding all the principal engineers of this country.
The chair was occupied by Mr. Hawksley, of London.
The following is a list of papers to be read during the
conference:-" On Self-Acting Machinery for Printing
Hosiery by Power," by Mr. A. Paget, of Lough-
borough; "On Mode of Working and the
Mechanical Appliances in the Midland Coal-field," by
Mr. George Fowler, of Nottingham; "On a Steam
Road Roller," by Mr. W. F. Batho, of Birmingham,
and Mr. T. Aveling, of Rochester; "On the Me-
chanical Ventilation of the Liverpool Passenger Tunnel
on the London and North-Western Railway," by the
President; "On the Conclusions derived from the
Experience of recent Steam Boiler Explosions," by
Mr. E. B. Marten, of Stourbridge; and " Description
of a Self-Acting Safety and Fire-Extinguishing Valve
for Steam Boilers," by Mr. G. D. Hughes, Notting- An express train on the Great Western Railway travels
ham. On Wednesday, August 3, the best means of at the rate of 60 miles an hour; that is, 1,760 yards a
preventing boiler explosions was discussed. Mr. E. minute, or 293 yards in a second. Now, does Mr. Us-
Marten, Stourbridge, stated that 219 explosions had borne seriously believe that if a missile were projected
occurred in England during the last four years, re- vertically upwards from the floor of a closed carriage
sulting in 315 being killed and 450 wounded. Eighty-in a train moving at this rate, to a snimcient height to
four were Cornish or Lancashire boilers, 53 plain retain it in the air for one second, that it would fall
cylinder, 12 marine, 10 locomotive, 11 agricultural, 204 yards behind its initial point of departure? or, that
8 upright furnace; 6 crane, 6 rag steamers, 14
domestic, and 15 miscellaneous. The causes were:-
Cornish and Lancashire, ill-formed tubes, weak com-
bustion chambers, domes, &c.; plain cylinders, flat
ends, and frequent repairs, resulting in seams and
rips; marines, weak flues, &c.; and locomotives, want
of stays. It was stated that the only preventive was I hope that your correspondent will not conceive that
constant and careful examination on the part of the I am guilty of any want of what he is so flattering as
owner. Government inspection was not recommended, to term my "invariable courtesy" if I counsel him to
as it would tend to relieve the owner of all respon-
sibility. Mr. D. Hughes, Nottingham, brought forward
a plan for the construction of a self-acting safety and
fire-extinguishing valve. It was generally admired,
the object being to secure boilers from the danger
arising from pressure and want of water.

ENGLISH MECHANICS' SCIENTIFIC AND
MECHANICAL SOCIETY.

THE fourth monthly meeting of this society was
held at the society's room, Mechanics' Institute,
Manchester, on the 3rd inst., when a paper was read on
The Ancient and Modern Means of Communication,"

by Mr. A. Tolhausen.

if a man fell off the main-top-gallant mast of a ship
sailing rapidly and smoothly along the Suez Canal
that he would not fall accurately at the foot of the
mast, because the vessel would have moved onward be
tween the time of his starting and that of his reaching
the deck?

go to the next circus that comes into his part of the world, and notice carefully how anything that one of the riders projects perpendicularly returns to his hand, and does not (as Mr. U. seems to think should be the case) fall to the rear of his horse; or how the said rider, when he wishes to jump over a flag or through a hoop as he careers round the ring, does not spring forward, (he would infallibly go over his horse's ears if he did), but straight up. Having taken this easy practical lesson then, I would beg my critic to spend a shilling or eighteen-pence in any rudimentary treatise on mechanics (such as Tomlinson in Weale's Series"), and read up the very elementary dynamics needful for its apprehension. Or he may turn to Mr. Kernan's paper on Science for the Young," on pp. 318 and 337 The speaker said that the double meaning of the of your current volume, for a statical demonstration of word communication as being, firstly, the making the composition of force, and so obtain an idea of how known of certain things, and secondly, the means of the proper motion of the engine which projects any passing from place to place, would necessarily lead given particle, never deserts that particle at any instant him to two distinct considerations of the subject. of its flight, but is always compounded with that of After giving a brief ontline of the different stages of projection. If the earth were moving at the equator written and spoken language, he compared the ancient with a velocity of rotation of 10,000 miles instead of mode of giving both diffusion and perpetuity to speech with the modern instructors of mankind "the Pen and the Press," and then proceeded to the postal and telegraphic systems as further means of communication without change of abode. The second part of the essay followed under the headings of inland and maritime conveyance, when the inland means of communication were considered, such as roads, coaches, rivers, canals, and the railroads, together with the maritime postal service. After the discussion the thanks of the members were awarded to Mr. Tolhausen

1,000 miles an hour, and it were possible to shoot a ball
absolutely perpendicularly from a gun (or rather a
howitzer or bomb) in vacuo to the height of two miles,
it would merely fall back into the muzzle again.
After which it is scarcely worth while to remark,
that Mr. Gould (p. 378 speaks, as I assume, of firing,
what artillerists call point-blank from west to east, or
east to west, and not perpendicularly at all; nor that
"the theory of projectiles" is a most exceedingly com-
plicated subject, albeit from very different causes, to
those assumed by Mr. Usborne.

I have sir, a favour to ask you, and it is this: merely let Mr. Firth write your "Astronomical Notes" for September. He is, obviously, burningly anxious to distinguish himself; and if he has got it into his head that I derive the very smallest gratification from what, after all, is little better than mere compilation, the sooner he dismisses such an idea the better. I underNotes" originally at the special request of some brother correspondents in these columns, and have endeavoured to frame them in such a form as should be useful to the mass of amateur observers who read THE ENGLISH MECHANIC. I should sincerely like those of my brother readers who have employed the "Notes" to have Mr. Firth', with his zodiacal signs, &c., &c., &c., for comparison. Besides, sir, you might sell another 10,000 copies or so weekly if it were known that Mr. F. "did the Astronomy," At all events, it would be only fair to give him the chance; as it is pretty obvious he will not fail for want of confidence, for that (as was once remarked of some one else) Cerevisiam haud tenuem de sese existimat.

A FELLOW OF THE ROYAL ASTRONOMICAL SOCIETY.
ERRATA IN ASTRONOMICAL NOTES FOR AUGUST.-Line

1, dele comma after "Greenwich; "line 3, sun's declina-
tion, for 1m. 319s. read 1' 31'9"; line 4," Cancer" should
be Cancri; line 26. "point" is printed for part:
in the second column line 9 from the end, "something'
is put where I wrote southing; in line 3 from end, dele
"then."

SEVERAL MATTERS.

dropping you a note, and now take up my pen to do
So. I must "follow suit" and congratulate you on
Within less than four
your very good digestion.
months you have terminated the individual career of
three publications by absorbing them into yourself.
I have had some experience of journalism, but I think
I never saw a speedier and completer change for the
better than has been exhibited by the ENGLISH
MECHANIC. You have enlarged your size and improved
your type; you give better paper and better engravings.
You give much superior information; you appear to
have multiplied your correspondents, as you have
certainly widened the scope and purpose of the paper.
I write this without intending a word of flattery. But
what pleases me most is the manner in which you
classified
The information is not
your contents.

[190] SIR,-I have for some time thought of

have

thrown together higgledy-piggledy, as it was a little
more than a year ago. "Order is Heaven's first law,"
said Pope, and order reigns in the columns of the
ENGLISH MECHANIC, Say I. Having said so much in
praise, I have also a fault or two to find-not so mach
Take, for instance, Mr. Proctor, for whom I have a pro-
with our editor as with some of our correspondents.
found respect. I sometimes say, "What a pity that so
able, and withal so generous a man, should be so im-
patient of other people's shortcomings." One would
have thought that his studious fellowship with the
heavenly bodies would have imparted to his style of
writing more of their calmness, dignity, and repose.
Woe betide any unlucky mortal who may be in the wrong,
and who may happen to assail Mr. Proctor; he is
almost sure to be transfixed with an epithet. And then,
again, the "Harmonious Blacksmith," who takes such
liberties with orthography and grammar generally.
Unfortunately he does this at our expense. A corre-
spondent some months since said that he considered
the space of the ENGLISH MECHANIC to be worth a
guinea an inch. The "Harmonious Blacksmith"
certainly says good things on a variety of subjects,
must look upon it as worth about a guinea a yard. He
but he uses such an extraordinary quantity of words
that he deprives the information he is evidently capable
of conveying of three-fourths of its value. The quickest
way from one point to another is a straight line. The
"Harmonious Blacksmith," instead of going from a
point to a point in a straight line, is sure to walk in a
or three
circle, and sometimes he describes two
circles before he gets to the point he aims at. This

may be funny to him, but it is tantalizing to many of
us who have very little time to spare. I wish, Sir, he
would have a little consideration for our patience and
your space.

similar reproach, so I will end by hoping that the I must take care or I shall subject myself to a gentle hints I have dropped may not be thrown away.

SUBURBAN.

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iron caps. These caps serve as holders for the four scrapers, which are inserted so as to have half-an-inch

[graphic]

bea ing within each cap.
At the back of each
scraper is a steel spring,
that allows the scrapers
not only to be com-
pressed and expanded
but also to accommo-
date their shape to any
unevenness that may
happen to be in the
tube. The peculiarity
about these scrapers is
that the scraping edges
are chilled in casting,
and then ground on
emery wheels to a sharp
edge. The point of one
edge in each scraper
projects past the other,
so that the tube gets
thoroughly scraped and
cleaned throughout its
entire internal surface.
The thread on the stem
allows piping to be
screwed on to suit any
length. The scrapers
can be made to fit any
tube, from 1fin. to 4in.
diameter, and the cost
is about one-half of
that generally charged
for other scrapers. They
are said to be durable,
and for the purpose
intended give entire
satisfaction.

[graphic]

КАРРА.

THE ELECTRIC LIGHT FOR PICTURES.

[192] SIR,-There are many things in this world that no "fella" can understand. Among those things I place my strangely erroneous statement that the evolution of light by electricity is unaccompanied by heat. Considering that before the year of grace 1820 I was familiar with and had repeated Davy's experiment of melting platinum within the luminous region between the two charcoal points, that I, of all "fellas," should have stated such nonsense, resembles my fellow correspondent's signature, "Pax Dei," in being past all understanding. When I read the falsehood and absurdity I had written, I felt strangely tempted to perform that act which has been said to indicate the utmost possible self-abasement, which act, Mr. Editor, I may, for the benefit of those, if any, who commit mistakes which make them feel as small as I did when I read mine, proceed to describe as the acrobatic feat of kicking your own seat of honour with your own foot. The force of self-abasement can no further go.

The advantages of seeing pictures by a light which hardly differs from that of day in its capability of shewing their true colours, and the absence of any objectionable chemical products of combustion, yet remain to induce my preference for the electric light over that derived from the burning of carbon.

THE HARMONIOUS BLACKSMITH.

EMIGRATION.

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THE EVAPORATION METER FOR BOILERS. (Described on page 490.)

as a good field for emigration, Texas is far, far surprises and valuable information. During
superior, and a want of knowledge as to the ad- days' ramble I have met with one or two indas
vantages of the State is one of the chief reasons, which may prove interesting to your readers. The
why more do not emigrate thither. To the small 1st-Whilst at Kew Gardens Station my atteste
farmer, or to the large one, Texas affords a certainty was drawn to a system of showing the times of the
with care and industry, of realizing speedily an inde- trains invented by the station-master. It is
pendency, and in many cases large fortunes. More simple, and saves many a minute of the porters' time
especially will this be the case when the existing A board and a few strips of pasteboard are all that
railways are extended further in, so as to form junctions requires. The time of the departure of every th
with the Union Pacific Line and others, and when the during the day is printed on a slip of cardboard. Th
Texas Lines are extended west into New Mexico, which are placed in regular order, and directly a train b
as a silver mining district is vastly richer than any yet passed a slip of blank cardboard is placed over?
discovered in the Western States. Texas having a sea- slip indicating the time of that train, so that a
board, though not with very good harbours, is an im-senger has only to glance at the table to know the
portant feature in a new country for imports and ex- of arrival or departure of any train, and so on. I
ports, and the time is not, I believe, far distant when to goodness every station master would adopt this pl
both Galveston, and more especially Saluria, in Mata- and place the board in a conspicuous part of th
gorda Bay, will have a vast number of ships going for-
ward and back to most parts of the world. From
Texas may be imported to this country vast quantities
of beef and mutton fresh, under an improved plan, and
also the same plan as is now carried out with regard to
Australian meat and its importation here may be
adopted with large profits. I think it is the finest
country in the world for English emigrants. I have
no pecuniary interest in advocating the natural advan-
tages of the State, either directly or indirectly. My
only interest is to help in any way I can some of my
poor hard-working countrymen here to go to a land of
plenty, comfort, and security.

[198] SIR, I quite concur in all your correspondent "W. M." says upon this question, and there is no doubt that the country he indicates, Kansas, is a fine field for the industrious emigrant, more especially at this time, for such as are connected with agriculture or stock-raising. At the same time I would say that Texas has all the, advantages of Kansas with a most productive soil, and finer climate, except immediately contiguous to sea coast, only in some parts of that State. In the north-western parts it is eminently calculated for the growth of wheat; in the western for raising stock, on the vast rolling prairies; while Indian corn, oats, barley, vegetables, and fruit, are also raised in great abundance. Agricultural labour is in great demand throughout the State, single men earning from £2 to £3 per month, with board and lodging. These wages enable a man to save money, and at the same time he has an abundance of good food. You can suppose this when beef and mutton are not more than 1d. per fb., and a bushel of wheat can be had for 3s., while as to butter, eggs, and poultry they are both plentiful and cheap. There is room in Texas for 20,000,000 of people. The Land Laws are very liberal. Land can be either purchased, or rented, at a cheap rate, and if a man goes there without capital he can have the loan of horses, implements, food for cattle, &c., without paying for same, other than the lender to have half of the crops, stock, &c., raised through the labour of the new comer. Of the eight million head of cattle supposed to be in all the United [Our correspondent certainly gives a glowing acCorrespondents would do well to States, five millions are in Texas. They thrive on the rich count of Texas. natural grasses all the year round, and only require to bear in mind that when they recommend so strongly be looked after from time to time to see that they are any particular state or colony or part of a colony to all right. I firmly believe that as this State becomes intending emigrants they write under responsibility, and more generally known a vast tide of emigration will set consequently should be careful in what they say; or, at in thither. It can be reached direct from English all events, they should take especial care to well inform ports, and steamers from Liverpool run to Galveston in themselves before they write.-ED. E. M.] three weeks or thereabouts, or the emigrant may go to New York, and thence by rail at a cheap rate. I have several correspondents in Texas, all of whom give a highly satisfactory account of the country. In comparison with Canada, which being British territory is therefore urged upon the attention of the public

station.

2ndly-I don't believe in the alarmist cry of a ba harvest. As far as I can gather, grain will produce average number of quarters. It is only upon light land that a failure occurs, and I opine that when the light land produces a good crop the heavy land fails, and vice versa. A fact I know is that here the wheat, beans. and barley are good-very good.

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Lastly, your contributor, Mr. Underhill, would shout with delight to be encumbered with fossils, &c., as I am. I ask, "Do you meet with any fossils when digging?" "Yes, sir: I will show you some I saved." 64 W. D. KING. Thank you: I am not much of a geologist ?" is this, sir? and this, and this, &c., &c., &c. You can take what you please, sir." "Thank you." Such is specimen of conversation held between your humble servant and those he questions. I declined taking specimens, thinking some one might prove more generous to the finder than I should, so they remain for the next wandering "English Mechanician" or geologian.

A SUGGESTION.-THE HARVEST, ETC.
[194] SIR,-I have an uncontrollable passion for
questioning. Sometimes such questions lead to pleasant

a

I have not seen your last issue, and may not see the next or the next. If, therefore, correspondents will take note of this, and querists content themselves by waiting, I will make up arrears as soon as I am near a library, and not so distant as three miles from a postoffice. C. H. W. B.

MOUNTING PLANING MACHINE.

[195] SIR,-Perhaps the accompanying rough sketch might prove of service to some of your correspondents desirous of mounting a planing machine on their lathe at a very small outlay. Should your space permit the insertion of the drawing I should feel much gratified.

A is a Z-shaped casting of iron, firmly bolted to the side of the lathe-bed by four bolts. To it is firmly bolted a compound slide rest. A gut band passes from the smallest pulley of the flywheel over two pulleys fixed to the bed of the lathe near the cone headstock; the gut passes along round a disc B having a radial slot, and bolt, which is adjustable, seen also from above. A rod passes from the bolt to the tail of the saddle S, which carries the object to be planed, between two jaws movable by screws or other means.

This machine works perfectly with light cuts for casting 10in. x 5in. and adjustable to 5in. in height. The edges of the lathe-bed are chamfered. The slotted disc was suggested by Munro's planer in South Kensington Museum.

GEO. CROWE.

REFERENCES IN PLAN OF SADDLE.

a. Screw to press removable bar b against casting. d. Casting to be planed.

e. Iron bar which can be fitted to various holes in

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saddle in the same way as bar e carrying pressure tearing it to pieces we may admit iodine water-this

screws.

diameters. In barley flour we see more cellular tissue than in wheat flour, and the granules of starch are more often found enclosed in their cells. When a black or dark mass is seen, instead of using the needles and blackens the starch and only colours the cell tissue slightly yellow; on turning up a strong light, the MICROSCOPICAL JOTTINGS, CHEMISTRY, ETC. object is clearly depicted. Portions of the husk and needle-shaped fragments are also seen in barley flour [196] SIR,-It is not many months ago since I which are never seen in ordinary wheat flour. Exsent you some microscopical representations of starches ceedingly small granules are also seen in this flour as of various kinds. If you think they are worth insert-in wheat, and of the same form, with the exception ing I send some more. Fig. 1 is the genuine Maranta that the hilum is more plainly seen. Fig. 3 is a sample of bean flour, which Dr. Hassall

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arrowroot, for which inferior varieties are often substituted. On p. 588, Vol. X., of the ENGLISH MECHANIC, I gave a figure of the Tacca arrowroot, referring to the Maranta, which I did not give; having now given it, your readers will be able to compare the two sorts. We often see in print that the starches are readily distinguished from each other under the microscope; certain kinds may indeed be thus distinguished, but to the "tyro" certain species are a source of infinite confusion. When potato starch is mixed with the Maranta arrowroot, and this is a case which often occurs in trade, it is not easily distinguished; the presence of the potato starch granules may be inferred by their size, but it must be remembered that there is no difference between a large Maranta and a small potato granule. There is, however, another mode of discrimination; the potato granule is strongly marked with concentric rings round the hilum-the Maranta granules exhibit this property in a much less marked manner; and again a few of the granules are too large to be classified as Maranta, and some of them are less regular in form.

NO 3

affirms was found in a sample of "cones."
The granules themselves are very peculiar, being ir-
regular in shape, and being marked with an elongated
and deeply furrowed hilum. Cellular tissue is also
seen, and there is a strange absence of the small
granules which would answer to those of wheat and
barley flour.

By the irregular form of the granule this kind of adulteration may be readily detected, but, strange to say, I have never had the opportunity of viewing it side by side with wheat flour in a commercial sample. The cut (Fig. 3) was made from a sample of beans, reduced to a fine powder by means of a file, which method answers exceedingly well for preparing samples of flours in the pure state for the purpose of practice in microscopical analysis.

"Sabbas" [4329] wishes to know what sort of a microscope to purchase. I should advise him to invest £5 in one of Crouch's instruments, with a fin. objective; this will show starches as the figures in this letter, and is nearly as good as one of Ross's instruments. If £5 is too much, get Field's "Society of Arts" Student's microscope, price £3 15s., with powers from 50 to 200 diameters; this is not nearly so good as Crouch's, but is a very good instrument.

On taking a sample of flour and magnifying it 200 diameters we find the granules nearly the same; in fact, to the tyro it would be the same, and the sample would be passed by as pure. But if they are only nearly the same, and not quite identical, there probably is a mix- In answer to "C. R. H." [4328], he cannot expect ture of barley with the wheat. Fig. 2 shows a sample to mount such an object as a cricket upon a glass slide;

he can mount parts of it, that is all. Heat must be applied to the balsam to melt it, the object placed in it; air bubbles withdrawn by an air syringe; the thin glass cover put on and set aside for some hours. Very small insects, as the diamond beetle, may be mounted in a small box, so that the insect is exposed when a glass lid is withdrawn; but this is only done when the wing cases present a surface worth looking at. Seeds should be soaked in turpentine; petals may be mounted in water cells containing camphor. Zinc rings are the best for beginners to manage, the gold size takes easily to the surface. Glycerine is also very useful in mounting vegetable tissues.

ART DEGREES, &c. [4355.]-"Beriro," if he is anxious to graduate, must do so at the London University. He must produce a certificate to show he is over sixteen years of age, pay a fee of £2, and go through a matriculation examination, held at the University of London, or at Owen's College, Manchester, Queen's College, Liverpool, or St. Patrick's College, Carlow.

The candidates for examination are examined in the following subjects:-Arithmetic, algebra, geometry (theoretical), the rst four books of "Euclid," mechanics, hydrostatics, hydraulics, pneumatics, and optics, inorganic chemistry, Greek and Latin. The examination of Jan. 9, 1871, will be from the following books:- Xenophon, "Cyropædia," lib. ii.; Virgil, "Georgics," lib. iii.; "Eneid," lib. iv. June, 1871, Homer's "Iliad," lib. ix.; Cicero "Orat. II., in Catilinam.” Besides the above, English language, English history, modern geography, and either the French or German language, at the option of the candidate. If "Beriro" passes the examination, after one years' study he is admitted to the higher grades, or examinations for B.A., M.A., D.Lit., B.Sc., D.Sc., LL.B., LL.D., M.B., M.D., &c. These are not given in the results of one examination; two examinations are required, except for the "Doctor" degrees, when three are requisite; and two years must elapse between the completion of "Bachelor" degree and the examination by which the Doctor's degree is obtained.

In query 4404, J. M." asks for a sketch of Griffin's (Griffith's burner he says, but I suppose he means the well-known Griffin's furnace) burner, and wishes to know how the blast is arranged. Griffin's furnaces are arranged for heating either at the top or bottom. The enclosed is a rough sketch of the burner. The

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air is supplied by a blowing machine, and a pressure of water upon the gas of in. is sufficient. The furnace for heating at the bottom is arranged thus:-A crucible jacket, crucible, and cover is placed upon a flat plate resting upon an iron stand. The lifter is then placed so that the crucible shall stand in the centre. A plumbago dome is then placed over the crucible, resting upon the lifter; the furnace is then built up with clay cylinders, and nearly filled with water-worn pebbles. When ready, the burner is connected with the gas on one side and the blowing machine on the other. The gas is lighted and pushed into its place in the flat plate whereon the crucible jacket rests. The blast of air is then sent in, and the progress of the operation can be watched by removing a plug in the lower cylinder.

For heating at the top-which arrangement, by the bye, is much the best-the perforated flat plate is placed as in the preceding, but instead of the lifter a cylinder is placed next. Over the perforation at the bottom is placed a hollow cylinder with holes in the sides and a solid top. Solid cylinders are now placed to the required height, and an outer clay cylinder placed in position. The annular space is then filled with pebbles, and a perforated flat plate placed on the top when the crucible and cover in its jacket has been arranged; the gas is then lighted, as in the former description, and allowed to play on the crucible before being thrust into its place, otherwise the cylinders will crack or the gas go out.

Possibly it may be unknown to "J. M." that Messrs. Griffin & Sons issue a guinea oil lamp blast furnace for melting metals. It will melt 1lb. of cast iron in twenty minutes, by the use of threepennyworth of oil at 3s. per gallon. The blowing machine is charged extra.

CHEMICAL.-The reason "Prussian Blue" [4401] failed in attempting to make potassium ferricyanide was passing the gas into the solution too quickly, the solution was too concentrated, or he allowed the liquid to get hot. The grand secret, if there is any in the matter, is to cool the chlorine before it reaches the solution; to pass it in slowly; and, above all, do not add chlorine in excess. The end of the operation is determined by the solution giving no precipitate with a ferric salt. By acting on a dilute solution, and afterwards evaporating down to crystallizing strength, the potassium chloride is left with a little of the ferricyanide in the solution, while the greater part crystallizes out. This is the method I have always employed, and have found no difficulty in obtaining a

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[197] SIR,-The clear and interesting description yougave the readers of your inestimable weekly by calling their attention to the subject-matter of a patent iron battery electro-magnetic engine, induced me to test their power in many ways, and compare the amount of work they would do, at what cost, taking the same number of cells of zinc and carbon (ordinary Bunsen battery), each having the same amount of surface exposed to the excitant. result has far exceeded my expectation; and my great astonishment is that it has been so long kept from the public generally, or so very little notice or mention of iron as such a powerful element when used as a sub

stitute for zinc.

The

I have read carefully most of the letters on electricity, &c., "given by that most worthy contributor to your pages"-"Sigma ;" and although I cannot endorse all he says respecting this "Slater's iron cell," I have nevertheless to thank him for the careful and com

prehensive method stated as the result of his experience. I will now proceed to explain the amount of absolute work done by the iron and carbon battery in 25 hours; ditto zinc and carbon (Bunsen), 25 hours; each a series of 24 connected to its voltameter and from thence to two gasometers.

At the end of an hour the zinc carbon had 42 cubic inches of the mixed gases (decomposed water) more than its rival; in 2 hours, 5 enbic inches only more than the iron; the 3rd hour the iron took the lead, and stood 34 inches ahead of the zinc; 4th hour, 764; 5th. 115; 6th hour, 1604; 7th hour, 214; 8th hour, 275 inches more than the zinc carbon. At this time I was compelled to leave them until the expiration of the 25th hour, when the iron carbon had the advantage by

1,762 inches.

There was considerable energy in the iron and zinc at this time, but the Bunsen was exceedingly feeble, as the galvanometer showed a deflection of only 14, while the iron stood at 37. I had previously weighed the metal before commencing. The zine had lost 9 ounces more than the iron and required 5 plates to be reamalgamated.

Experiment No. 2.-I resolved to try them another 25 hours, again to compare their work and comparative cost, which were as follows:

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or

271b. at 14d. Attendance

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8 10 3s. 104d. against 12.,- being an advantage of more than 8s. in favour of the iron cell, saying nothing of the extra work done by the iron. The result of the second day's trial was more in favour of the iron, more gas being liberated and much more zinc lost by local action. Indeed, some of the plates were used up, while the iron showed no sign of ill-usage beyond a uniform thinning. I find no use in making the solution in contact with the iron very strong, as there is a useless evolution of hydrogen with but little extra power; and when the porons pots have been used a few days I do not find that the solution rises in them as "Sigma" speaks of.

Sea-water is a uniform and excellent excitant for the iron. I am using this battery for an electric light with great satisfaction; and am sure that when its great power and the cheapness of the working cost is made known it must become a great favourite.

As I must not trespass further now, I will, if agree able to your readers, send the result of further experiments with a series of 36 cells. I wish you and your scientific contributors every success. OMEGA.

BICYCLE RIDING AND WALKING. [198] SIR,-As varions letters on the "Bicycle" have lately appeared in the ENGLISH MECHANIC, all very much in favour of this new machine, I think a few words from myself-I having been in continual practice for over twelve months-may be of some interest, and save much disappointment to those of your readers who are about to learn.

Some time back, at the first introduction of these machines, I, Herman Sloman, and others, while advocating the use of them for amusement and exercise, deprecated their utility for practical purposes or economising force. A correspondent at that time calcu

lated theoretically the difference between bicycle riding and walking; he concluded an elaborate calculation proving that the force necessary for walking a distance, say five miles, if put into use on the machine, would only carry three miles, or little over two thirds. These calculations were based on the fact of the bicycle not taking the rider, but vice versa, the rider pushing the machine, of which, by experience, I am painfully

aware.

endurance.

I have travelled most of the Surrey and Kent main road-, and find (with the bicycle), taking the roads as they come, and using force enough to thoroughly exhaust myself on a twenty mile journey, an average of about four miles an hour to be the outside speed, I can continue the journey-this being less than my walking pace. The machine I ride is a 38in. wheel; my height is 5ft. 10in.; weight 11 stone. On a walking tour I manage generally to do about 30 to 40 miles a day, which, up to the present I have not been able to do on the bicycle; although, had I trained twelve months for a walking expedition, I am satisfied 50 miles within the 24 hours would be rather under than over my power of My experience makes me believe that those of your correspondents who write of travelling 15 miles an hour on the bicycle must either be joking, or totally unacquainted with the subject. I will admit that on a level asphalte road, say a quarter of a mile round and perfectly level, a very high rate of speed may be obtained; and so it is with the locomotive, which on a plain road travels at 10 miles an hour, but on rails, where the friction is reduced to a minimum, 40 miles is done easily. I therefore consider the bicycle a toy, and only fit for exercise; although there are some men particularly fitted for these exercises, which perhaps may explain some of the astounding feats of which we read; but I find, on enquiry amongst my friends, that the majority join me in discarding the machine for all practical purposes. If enthusiasts think it necessary to have a manual machine for utilizing force, I cannot recommend them anything better than a round wire cage similar to that of the squirrel; by imitating the movements of that industrious little animal, they may produce motive power to their hearts' content. A wheel-barrow, also, would do, but has the disadvantage (as some bicyclists say) of not utilizing the weight of the body. I can quite agree with your sensible, but facetious correspondent, W.," who on a long journey thinks it better to carry the bicycle; and I am perfectly satisfied, joking aside, that on ordinary hilly and dusty roads it is much easier to walk behind and push the machine with the hands than to mount and force it forward by using both hands and feet. R. G. BENNETT.

POST-OFFICE ORDERS.

[199] SIR,-You will be as well able as any one to judge of the expediency of my proposition, and hence it should interest you to insert my letter. There are many of the readers and subscribers of your journal who are constantly wanting to send small sums to you, to their tradespeople, to their children at school, and to their correspondents at home and abroad; and the same applies to the world at large. Now, stamps are troublesome to all parties, and a temptation too strong for many postmen to resist, and a 3d. Post-office order is a heavy tax on 6d. to 2s. 6d. Hence, I would ask, could not a short and counterpart ticket system be adopted by the Post-office authorities, at d. or 1d. charge, to be more convenient and safer to the public. And again, as an old colonist, I have often to write for advice, and often to those who don't like to pay 6d. to oblige me; and which I quite as much object to their doing; but as our stamps are useless there I do not like paying 4d. or 6d. to send out 6d., and therefore do not sometimes get replies, of course. And I am but one of many tens of thousands, and I say the public servants ought to study the public convenience and interests in some suitable way; but by your inserting the above it may lead to a useful consideration of the same. L. HEWETT, C. and M. Engineer.

to me.

MUSICAL.

[200] SIR,-In looking over the pages of our MECHANIC this week, my eye caught a letter headed "Musical," in which my name figured; and I naturally expected to find something interesting and instructive, at least for myself. I am sorry to have to say that I was disappointed. I do not wish to be harsh to any of our correspondents, but why should people write upon subjects about which they evidently know nothing ? Nearly the whole of the letter is simply unintelligible The part commencing “and why should signatures," and ending "flats or sharps," is particularly obscure; and after puzzling over it for half an hour, I am almost inclined to follow the example of our excellent "F.R.A.S.," and offer a small prize to any one who will discover what it means. "Music" seems to think that something "ought to be glaringly apparent" from his arguments (?). Perhaps it is all clear enough to him-I can only say that I do not understand it. Then there's the question:-"What remains of the seven, being flats or sharps." I'm sure I will not pretend to say; perhaps "Music" will kindly give your readers the interesting information. Will "Music " tell us something further about "the very effective mode of marking expression by joining the stems of the notes,' as it is possible that some others of our readers, like myself, may never have heard before of such a mode of marking expression? "Music" first enquires what is the origin of the stave, and then immediately assumes that without doubt "it represents the strings of an instrument," &c., on which (wrong) assumption he pro

ceeds to enquire:-"could any notation be Eze musical?" This appears to me a rather a establishing one's point. In conclusion, Music himself pointed out the only means of gaining a ledge of this subject, and I should advise him to s himself vigorously in the way he indicates, so the next letter may be a little more intelligible.

I notice on page 431 a query upon taming br temperament. A proper reply to this would good deal of space, and require a small shetr musical type. If our editor is willing to make ro will give the information next week, as donites would interest many readers besides the queri J. N. TRAILER [We will "make room."-ED. E. M.]

MR. RUDGE'S AIR PUMP. [201] SIR,-Will your correspondent, Mr. Pat. have the goodness to give some description of pump? At present, we are indebted only to e. Mr. Taylor's engraving for a very good elevatin instrument, but this, for practical men, is com worthless; and as the greater part of your a practical men, it is a great desideratum Dr. formation should be of that character in or.. may be useful. And as you will see, from th brings the mercury down to the 30th part of Ez Now if the pump will produce sach a vacuum, do not see how the "photos" can show it, thes. do what few pumps will do.

He says,

What does Mr. Rudge mean by "a metallic pis mechanically fitted ?" I have not the fainted.. ception. I know what "metallic pistons" are in general scientific n-e of the term, but they are, inapplicable to the air pump. Again, how a "stude box" can be " composed of twelve collars of leather I cannot comprehend; or in what way the chamber," "the piece of hollow brass," the "other pieces of leather," and the end of the gland connected, I am quite at a loss to discover. Again, be speaks of the valves; but he does not say what valves, of where they are situated; and there is no indication in the drawings, admirable as they are, to show where or what they are.

are

From the position of the pipe leading to the cylinder I opine that it is on Tate's plan, but I should be glad if the maker would give a more special and accurate account of the pump internally, the external construetion being sufficiently clear from the engravings. Will he also be good enough to state the kind of oil silk he uses and where procurable; what kind of oil he uses; and how the piston is oiled?

I shall be happy to answer any enquiries on the INDUCTORIUM. subject of my coil.

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MR. PROCTOR AND MR. LOCKYER. [202] SIR,-I thank "Luke the Labourer" Mo "wishing to be hard upon me. He is most and considerate. Yet I should deserve no mer ever if I had really acted as he supposes. 7 with, I could not even plead ignorance, read all Dr. Dick's charming works on astrea even if not, how could so obvious a fact as t ment of the sun from certain parts of Satma520 ring system-a fact which every one who has the planet through a telescope can see for liste become the subject of a reclamation. The preposterous, and had I made so Indierons & G "Luke the Labourer" might have been hard ape2 with a vengeance.

Premising that I charge Mr. Lockyer with noti worse than forgetfulness, I will now submit to ye readers the passages from my " Saturn and its Syste and from Mr. Lockyer's Elementary Lessons # Astronomy." After referring to Table XI. (forming octavo pages closely crowded with figures, which I occupied seven weeks in calculating, and every deta which was absolutely new), I proceed-“From this ta it will be seen that (for instance), in latit 40 (Saturnian), the eclipses begin when nearly thr years have elapsed from the time of the autumn equinox. The morning and evening eclipses contre for more than a year, gradually extending until th sun is eclipsed during the whole day... These tota eclipses continue to the winter solstice, and for a corresponding period after the winter solstice; in ai for 6 years 2364 days, or 55430 Saturnian day This period is followed by an interval of more than a year of morning and evening eclipses. The total period during which eclipses of one kind or another take place is no less than 8 years 292-8 days. If we remember that latitude 40 on Saturn correspones with the latitude of Madrid on our earth, it will be seen how largely the rings must influence the conditions of habitability of Saturn's globe, considered with reference to the wants of beings constituted like the inhabitants of our earth."-"Saturn and its System," p. 181.

In the "Elementary Lessons of Astronomy," Art 276, Mr. Lockyer writes:

"In latitude 40 we have morning and evening eclipses for more than a year, gradually extending until the sun is eclipsed during the whole day. and these total eclipses continue for nearly seven years; eclipses of one kind or another taking place for 8 years 292 days. This will give us an idea how largely the apparent phenomena of the heavens and the actual conditions as to climate and seasons are influenced by the presence of the rings."

And, as I said in the letter on which "Lnke the Labourer" comments, there is nothing to show that

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