It is

a leaf of laurel or ivy, as being thick, leathery 53388.1-Jupiter's Satellites.-"A Foreign
leaves, they are more easily manipulated. The Subscriber" will find an answer to his question in
time for boiling depends upon the thickness of the "Celestial Objects for Common Telescopes."
leaf, and experience is the best guide.-W. B. very difficult to identify the satellites by a simple
last week, fourth line, read "courses of brick-Almanac or Whitaker's Almanack, and attend to
(53357.)-False Perspective.-In my answer inspection. The querist must get the Nautical
work," not "curves."-EYE WITNESS.
the daily configurations there given. With a little
care, he will then identify them easily. The former
[53370.]-Making Thin Platinum Wire Red-is 2s. 6d., the latter 1s.-S. M. B. GEMMILL.
Hot."Sigma" does not give the B.W.G. of his
platinum wire, so it is hard to tell what battery
power would heat it. I have heated wire of 3
B.W.G. in. long white hot with three Bunsen
pint cells. in. of 29 B.W.G. red hot with same
cells. I daresay "Sigma's" cells are not in good
working order; perhaps the zincs are worn or the
acid long in use, both of which would greatly de-
crease the power of the cells.-C. M. C.

The resistance varies directly as the length and as
[53393.]-Equivalent Resistance of Wire.-
the specific resistance, and inversely as the sectional
area. Hence, denoting the length of the proposed
wire by x, and using the fraction as the equiva-
π
lent of we evidently have the equation-
× 2·8 × 10
102

4

=

(-056)* ×

x = 7 x 10 x 003136 × 1
= 1-7248 × 1015

[53370.]-Making Platinum Wire Red-Hot.-
It is impossible to answer this question. What is from which, by multiplication and cancelling, we
meant by a thin platinum wire, and what length?
A single bichromate cell will make thin platinum-get-
wire red-hot, for this is a common instrument in
form of a small lighter, in which either a jet of
hydrogen or a benzoline lamp is lighted by pressing and dividing this answer, which is in inches, by
the zinc into the liquid; but the wire must be really 6:336 x 10' we obtain 2:722 x 10 as the number
fine and very short. It is also a question of current of miles. I suppose this is a London University
and resistence, governed by well-known laws. A question: it looks like one.-WM. JOHN GREY,
coil is of no sort of use for this purpose.-SIGMA.
Elswick Science School.

the direct question put by the queriet, for the
emple read that I have never examined the
sustrument referred to; but if a few remarks on the
metoda of making stops are of any use to your
readers, here they are. The question, stated broadly,
is How can two sets of reeds in the treble half of the
regater be made to give five stops? and the answer
as ply. In a variety of ways. To make the
question a little broader still, I might ask, how is
It posible to obtain, say, 20 stops out of two rows
of reeds? and it may be as well to treat the matter
on that ground. The firm to which the querist
obviously refers has always had the honesty to say
how many reeds their instruments contain, and
that is in fact all the purchaser needs to know; the
reat he can see for himself. Now, with two rows
of reeds we can divide each into two sets in the
ordinary manner, or we can put a mute to each
octave, and so have ten stops at once; but that is
not the method adopted, though some stops, it is
trus, do consist of only about 13 reeds. We can,
on a two-row board, make quite enough stops to
satisfy anybody, dividing the rows into two of 2
octaves each, or making the bass two octaves and
the treble three. In the first place a difference
(that expressed by the word "Doice") can be made,
by causing the mute to open only a slight distance
Austead of to its full extent-that gives two effects
on one set of reeds, making four where there are
two rows; but the advantage of the second row
comes in here nicely, for by opening one mute
fully and the other only a little way, we get
another effect, for while in one case it gives the
dolce when applied to one set only, by making that
set slightly flat compared to the other, we obtain
more or less of the wave. Now, taking the case
cited by the querist, we have two 8ft. half-rows in
the treble of 24 octaves each. We will call one
melodia, the other clarinet. The first will be voiced
of the usual round tone, the second will be reedy;
and when their respective stops are drawn, they
will be in unison. By fitting another stop which
will open the mute of the clarinet a little way, we
can obtain what we may call clarabella; and by
fitting another which will open the melodia wide
and the clarinet only a little way, we obtain the
voix celeste. (I explained that little matter on
p. 408, Vol. XXVI.) Now we have to make the
oboe. Well, hitherto we have been dealing with
the ordinary arrangement in which the wind enters
the tubes over the heels of the reeds; but it will
occur to the ingenious that there is no reason why
apertures should not be made in the tops of the
tubes, so as to allow the wind to strike vertically
on the free ends of the reeds, which will be found
to have the effect of slightly flattening them; and
if we also admit the wind by opening the mute, we
shall create such a hubbub in the tubes that we can
[53375.]-Shrimping Net.-Use either flax or
call the sounds either oboe, or bagpipe, or any-hemp twine; mesh in. Steep for a few minutes
thing else we please. Now, if we apply this top in hot bark liquor, drain off and dry. This is the
mute to one row we can do the same to the other, best preservative. "London" will find it most
and by admitting wind to one set of reeds verti- tedious work, and very difficult; if he will advertise
cally and to the other horizontally, we shall obtain his address, I will put him in the way of getting a
another effect, so that if we have 2 rows of reeds, good secondhand one; there are always some to be
say, we shall experience no difficulty whatever in got cheap here at this season.-SCARBORO'.
filling the board over the keys with stop knobs.
The simple plan of making a row of holes through
the upper part of the tubes, so that the wind strikes
vertically on the vibrators, is an efficient method of
getting a celeste while retaining the reeds in unison
with the other 8ft. set when both take wind in the
usual way but the other plan can be tried on any
instrument by drawing one stop full out, and then
pulling another out only so far as is necessary to
Cause the reeds to speak. I think I have said
enough to show those who understand just the
rudiments of the matter, that by this regulation of
the amount of opening of the mute, and by the use
of the top mute, which takes the wind to the reed
in an entirely different direction, there is ample
scope for the skilful stop-maker, and no difficulty
in putting even more than five stops to two sets of
reeds. Whether they are worth the trouble is

quite another matter.-ORGANON.

[53373.]-Engine Query.-To "ENGINEER,' Dewsbury-Once knowing that a certain pressure and speed is required for a certain weight, we could hardly expect that a less pressure and speed would turn that same weight; if so, we should have obtained something like perpetual motion. But in this case we fall far short of that, for I find that there needs no difference of weight in the mill, for both diagrams give very near the same average pressure throughout the whole stroke, and even had the average pressures been unequal, I should have attributed the loss of power to the throwing off of some part of the machinery at the instant you were taking the diagram, or to some fault in the indicator, such as dirt on its piston, &c. I have scaled your diagrams very accurately. and I find that No. 1 gives a somewhat higher average pressure (whatever that pressure might be) than No. 2, and this is only natural, since No. 1 has a higher pressure at the termination of the stroke, and is a little crippled at the instant of exhaustion. Hence a greater average pressure is required to turn the same weight; but you must have a large area and high speed if this gives 30 I.H.P. Any further information that I can give I will do so with pleasure, or if you advertise I will correspond with you.-ENGINEER, Dewsbury.

[53378.]-Frumenty.-The wheat should be "creed" for four hours; this is done by putting it in a close jar, covered with water, and placing it in a rather slow oven, when sufficiently "creed" pour it into basins to cool. When cold, make it into frumenty in the usual way.-SCARBORO'.

[53378.]-Frumenty. The correct word is furmety, I believe. Soak your wheat overnight, boil next day for four or five hours, boil gently. Eat with milk and sugar. The furmety of the restaurants is crushed wheat boiled until almost pasty. For myself, I like the grains whole, as then I have something to chew at.-T. R. ALLINSON, L.R.C.P.

[53396.)-Horology.-1st. See that your pinion is properly centred and marked well. Most likely you have used too strong a drill bow. 2nd. Perhaps the ratchet wheel is put on tight on the square. Give a gentle tap or two to loosen it, or if that is not successful take hold of square in watch key, and with a pair of pliers try to unscrew the part that has got the hook in it. Failing that, look for a pin that runs through it. -PENWITH.

[53396.]-Horology.-Remove from your turns the part which holds one centre, and turn the T-rest round to face the other; centre the pinion with fine point of graver; place pivot in the centre of turns hold the drill in pinvice; place it across the rest with your finger resting upon it; no drillstock required; place ferule on the pinion and work the bow with your right hand; a slight groove made in rest for the drill will be of advantage. You can purchase a drilling tool which a child could use for about 98 If you wish to remove the arbor, place on a key, and with soft pliers unscrew the part in barrel. Old Swiss watches have a pin pass through which can easily be removed with joint pusher. The arbor should not be removed for putting in a spring. Place spring on the arbor holding barrel, and spring with thumb and finger of left hand, and wind it in with a key on the square.-MODEL. wire on A, and connect the machine on the shunt [53397.]-Dynamo.-Wind about 101b. of No. 10 system. This amount of wire on A will give plenty of current if the res. of vat. is very small.-W. H. E., Coventry.

[53402.]-Putting Pads on Flute Keys.-I have found a small quantity of guttapercha answer be used hot.-G. FRYER. the purpose admirably. The guttapercha should

[53408.]-Electric Light.-You must have had a short circuit in the cell that was hot. I don't see how it could have been a 10 c.p. lamp, se these take 20 to 25 volts, and you had less than 12 volts with six cells. Did you add the sulphuric acid by drops to the bichromate.-G. D. GOOLD.

UNANSWERED QUERIES.

Since our last W. J. Grey has replied to 52637, 32835, 52998. Improved Carrier for Lantern Slides, 482. 52831, 53038, 53039. Removing Tricycle Wheels, 483.

Pump Suction, p. 567.
Unit Jar, 567.
Pumping Water, 567.

53093. Turning, 567.

The numbers and titles of queries which remain unan[53383.]-Field Magnet.-The arms of your swered for five weeks are inserted in this list, and if st F.M. should each be 12in. by 8in. by lin. The unanswered are repeated four weeks afterwards. We tru most convenient way would be to arrange them our readers will look over the list and send what informanos vertically with the A. at the top. A shunt machine they can for the benefit of their fellow contributors, [533561-Microscopical.-A leaf is composed is much better than a series for running incandescent of three distinct tissues, in layers, the upper and lamps, because by lowering the speed you can ruu under cuticles, in which are situated the stomata or will drive. This is not so with a series machine. one lamp as easily as the full number the machine breathing pores, and the interior, more fleshy part; Put about Glb. of No. 16 on each leg, and connect 52924. all are cellular. To separate these, which is necessary for mounting, cut the leaf into small portions as a shunt on A. Nearly 1-h.p., about five 16-c.p. between the larger veins, and place in a Florence Swans. You will not be able to run the machine flask, with a mixture of 2 parts water and 1 part for above one hour at a time; in fact, these 53080. nitric acid, sufficient to cover. Hold it over the machines (H armature) are not fit to be driven by 53052 flame of a lamp, and let it come gently to a boil: power except for short experiments.-W. H. E., 53998. keep the flask moving, and when boiled for about Coventry. a minute, rotate the liquid quickly, and throw the (1) The precipitate is contents (while boiling) into a basin of cold water; sodic silico-fluoride. (2) The clear liquid is hydro-53109. this will separate the tissues of the leaf, and they chloric acid; the reaction iscan then be removed by a camel's hair pencil and à H.SiF + 2 NaCl noodle. To finish the cuticle for mounting, it recommon and quires to be reboiled gently in a fresh mixture of salt acid and water for, say, a minute, which will renNa,SiF + der it very clear and transparent, and remove all sodic and particles of the interior tissue which may be attached silico fluoride i to it Nothing further is required except to tho-(3) Whether they are poisonous or not I don't roughly wash in clean water to remove the acid, and it can be mounted when dry in glycerine jelly, Dean's gelatine, or dry. Make the first trial with

[53384.]-Chemical.

Hydrofluosilicic
acid

produce
2 HCI
(hydrochloric
acid.

know; but I should not like to try the experiment,
as hydrofluosilicic acid is, I believe, poisonous.-R.
A. Ř. BENNETT.

53100.

53104.

American Cane-built Fishing-rods, 368.
Water Engina for Organ Blowing, 568.
Small Boiler, 568.

Soldering Cables into Switch-boards, 568.

AN international exhibition of metalwork is to be held next year at Nuremberg. It will be held in the new museum building, and will contain speci mens of the art of the silversmith and the worker in brass and copper, together with the machinery and appliances used in the making of jewellery and art metalwork. The exhibition will be open frem the middle of June to the end of September.

QUERIES.

[53409.]-Driving Lathe by Spring.-I wish to drive a small lathe by some automatic power. Cannot I do it by a flat or coiled spring wound up !-H. J. MORRIS.

number.-E.

[53434.]-Bird's Eye View.-In what way do the rules applied to ordinary architectural perspectives differ from a bird's-eye view? I am particularly at faut with the station point and horizontal line.-VITA.

medical correspondents will be good enough to say if I and Halske dynamo and lamps, for example, what would ought to apply anything to them, and what I may expect, be the cost of an installation such as mentioned? Can to take place? Also if they will say what circumstances accumulators be used in connection with the electric determine whether or not a nail will come off, with light? Not hav ng access to back numbers of ours" a description of the mode of growth of nails at the root, for more than 15 months, I beg for information anew if and of way in which old nails come off? Also if in any it has already been given. Perhaps it would be feasible circumstances a new nail never comes ?-SUFFERER. to utilise electricity as a motive power for the railway. A [58422.]-Splitting in Deals-to Prevent.-My dynamo could be placed in the mountains-source of [53410.]-Magnesium Stars.-Can any one tell trade compels me to stack (r pile spruce deals in the wood, as there fuel costs about 5s. a cord. Data in me how to make them? They are not intended for trade open air for seasoning purposes. The exposure to the regard to the above would greatly oblige.-SPRINLLE purposes, but for a gratuitous time signal. If private sun and wind splits the ends of the deals considerably, BRADEN, Sombrerete, Mexico. information is preferred, see address column in present and in many instances makes them useless for my purpose. Consequently, I suffer considerable loss during [53411.1-Condenser for Steam Launch.-twelve months. How can this splitting be prevented? Before fitting out my steam launch this season, I wish to Can any cheap solution, or other remedy, be applied to fresh water to the boiler, as the boat is much used in salt of the weather on the exposed ends of the deals ?-SUBfix a condenser to her to get a vacuum and to supply the ends, when stacked in the pile, to obviate the effect water, and the tubes get covered with salt. Will anyone therefore kindly tell me what kind of condenser I ought to bave, or how to make, and what size? Also what ought to be the cubic capacity of the air pump? I have heard that the exhaust steam has been condensed successfully by passing it through a tube on the outside of the boat. How many square feet of condensing surface is used generally in marine engines? And is it necessary for the steam to be reduced to several pounds below the atmosphere before being condensed ?-STEAM LAUNCH.

SCRIBER.

[53423.]-Testing Coal.-I shall be greatly obliged if some reader will kindly inform me with a sketch of some contrivance by which I can test col as to how much water I can evaporate from a given weight of coal? I should test the same with Lancashire boilers with very good draught; but have not the convenience to measure the water.-STEAM.

[53424.]-Potter's Wheel.-Can any reader give me any particulars concerning the construction and 153412.-Load on Girders.-A cast-iron cylin-working of the potter's wheel? Could an amateur make drical tank, 14ft. 6in. in diam., and 6ft. deep, is sup- one, or is it too complicated -A NEW SUBSCRIBER. ported on rolled iron girders, 6in. by 9in., placed 2ft. [53425.]-Post Office Batteries.-Wanted a deapart from centre to centre (as shown below). The scription of the Leclanche batteries now used in the Government telegraph departments. with approximate dimensions of the zines, or any other particulars that can be given? Also what kind of battery was used before they adopted the Leclanché ?-E. M. F.

weight of the tank and the water it contains being known, will any reader say how the load on each girder is calculated?-The span is 17ft.-SIA.

[63413.]-Hydraulic Balance Lift.-Will any reader kindly tell me how the above lifts work? I do not mean those where the cage and ram are balanced by weights. There are some now made by which the makers claim to use part of the water (which otherwise would be wasted) over again, which I think is done by the weight of the ram and cage coming down, and so forcing the water into an accumulator, and so using it over again; but how I should like to know.-A. Y. Z.

[53414.]-Self-sustaining Lifts.-Can any reader tell me the reason that when a load is put into the cages of these lifts they will not run down. I have noticed on the pinion shaft a circular box; but do not know what is inside, as the lift will not run down unless the endless 1ope is pulled.-A. Y. Z.

[63415.]-Slide-valve Cylinder.-The cylinder of my model engine formerly had a glass barrel, for which I have substituted a brass one, and I find that one end of it does not fit tight enough to prevent the steam getting out. White lead will not stay in it. Will any reader advise me as to the best way to manage?-EDDIE

[58426.]-Dissolving Wood.-Can any of my fellow readers give me some information about a liquid called the " bisulphite of lime process" employed to dissolve the resinous matter of wood in making paper out of wood pulp, instead of using a caustic liquor composed of soda ash and lime, which is very expensive. The former process is used largely in Germany, and I am very anxious to know how the liquor is made. Are there any books on the subject ?-J. CHAPMAN.

[53427] Boat Launch. - Querist would feel obliged if any scientific reader wou'd suggest any easy method of floating a boat, length 100ft., beam 29ft.. depth 11ft., flat bottom, weight about 300 tons. The boat is on the seashore about 2ft. too high for the tides.-ENGINEER.

[53428.]-Small Dynamo.-To MR. BOTTONE.Relative to the construction of the small dynamo described in "ours," I would be thankful for the information as to what will be the approximate number of layers of wire that is supposed to go on F.M. I have 71b. of No. 16 wire (as supplied by the party from whom I got the castings, and who says it is the proper quantity), five layers of which I have got on, but rather hesitate on putting on more, on account of receiving the information from another party that the correct amount for F.M. is 6lb. My armature being 13in. diameter may make the difference. In other respects, the dynamo is the same as described.-F. CORRELL.

quantities of glue; but the report has always been "Not
[534385.1-Strongest Glue-I ship at times certain
strong enough." Will some friend of ours" oblige me
with a recommendation, and, if possible, with a rapid
method of testing it ?-NEGOCIANT, JR.

damages be claimed for a little boy who met an accident,
[53486.]-Fmployer's Liability Act.-Can any
which necessitated the amputation of the arm higher up
then the elbow, in the following manner?- He and his
father were employed by a widow farmer to cut corn with
the reaping machine, and while they were at their work
the employer's son, a chemist, and at home for his holi-
days at the time, came to the field to shoot rabbits that
might come out of the corn, and, owing to the shooting,
the horses were frightened and ran away, and the little
boy was thrown into the knives of the machine with the
above result. The employer is a fairly well-to-do farmer,
and the employed are only poor people. Can any damages
be claimed, and how much, if any, damage is like'y to be
allowed on an appeal to a County Court?-FRIEND OF
THE POOR.

of an endowed chapel be turned out by the trustees when
(53437.)-Legal-Chapel Affairs.-Can a minister
his moral character cannot be impeached, and when he
fulfils, as far as he can, all the duties of a minister? and,
can the minister and the congregation appoint additional
trustees without the consent of the old ones!-GWILLI-

AMUS.

[53438.]-To Mr. Wetherfield.-Kindly inform me what is the cost of articles of clerkship to a solicitor? How long is the term, and can that term be shortened by hard study? What is the course of study, and what are the subjects of examination?-JUNIOR.

[53439.]-Venetian Blinds-Will some reader give me the way of setting to work to retape Venetian blinds? -J. W. B.

[53440.1-Music Engraving.-Will any of the readers of "ours" kindly inform me respecting the above, the tools, plates, &c, and manner of procedure, or direct me to a published work (if any) on the subject!IZAAC THOMAS.

other correspondent, kindly inform me the length from [53441.1-Double Bass.-Will "Fiddler," or any nut to bridge of strings, also the weight (in pounds) to bring lowest string up to pitch (AA)?- IZAAO THOMAS.

[53442.]-Kopf Violins. - Will some reliable authority of "ours" on violin matters inform me if the Kopf violins are considered of first-class make? I have Kopf violins, but although I have my own private of inion heard some violinists speak in unfavourable terms of the of them, I shall value the opinion of some of our able violin correspondents on the subject. I solicit a reply from none except those thoroughly acquainted with violin construction, such as our esteemed friends "Fiddler," "War," or "Captain Cuttle."-G. FRYER.

[53429.)-L. & Y R. Engines.-Will Mr. Stretton, the bogie express engines of this Co. Also of the fouror some other correspondent, kindly give dimensions of coupled passenger locos. (leading and driving), built on the G.N. model, with domes added more recently, and of the four coupled passenger engines (built by the Co. themselves, I think), of the No. 40 class? Any information as to the manner in which the above engines do their work, and how they are liked by the drivers, would, I am sure, be appreciated by many Lever.-Will any of our horological correspondents [53443.]-Converting Verge Watch into readers of the E. M.," as it is seldom we get any in- kindly give instructions how this is accomplished, and [53416.)-Legal.-A. dies, leaving a business and formation respecting the engines of this Co. Can any state the necessary tools required, or refer me to any some property to be equal y divided amongst his three reason be given why this Co. invariably have their en-back number in which I can find the required informadaughters, B., C., and D., whom he leaves as sole execu-gines built with smaller driving-wheels than most other tion? I want to experiment on a good old verge watch. trix. B. gets married, and draws one third out of the Co.'s passenger engines ?-AURANIA. business (her share of it), retaining her interest in the property. She now wishes to be paid her share out of that. How would you advise her to go about it, supposing C. and D. are unwilling to divide ?-F.

MCCORMICK.

53418.]-Spent Oxide.-Can any one inform me of one or two methods of determining the S in spent oxide from gasworks! There is one which consists in burning the S in presence of O, and passing the SO, into a solu tion of I. Please give example and descripti: n of apparatus required.-GAS WORKS..

[53419.] Oscillating Engines. Would any reader tell me why oscillating engines of a high power are not made to work the slide by the oscillations of the cylinder, as in small engines? Are the latter capable of

-G. FRYEB.

other amateur sailor, kindly describe the floating anchor, [53444.J-Anchor Floating.-Will J. Brown, or and how I can construct one? I also want a book containing information for fitting up a small cruiser as regards lockers. furniture, utensils, &c. I have "F. and A. Seamanship" and "Corinthian," but require smaller details. Any hints on 3-tonuers would be esteemed.-R.

[53430.)-Illuminating Face of Clock.-I wish
to illuminate the face of a clock sin. diam. at a distance
of 13ft. from the source of light (an Argand gas-burner).
Will some of ours" tell me what lenses I require? I
have tried two opticians. The first sold me a pair of 4in.
lantern condensers, and told me that was what I wanted;
and the second gave it up for a bad job. Surely some of
can help me out of my difficulty. What I want
to know is, Size and focus of lenses, and how placed ?-
using, if possible, the 4in. condensers I have. They are [53445.1-Watkins' Range Finder or Tele-
plano-convex-the convex sides together. -ILLUMIN-meter.-Please describe the construction and use of this
ATOR.
instrument.-GLATTON.

"ours 39

ladies admitted as students, and at what age? what
153431.]-Lady Doctors.-At what hospital are
are the subjects for preliminary examination? What
are the fees and necessary expenses, and at what age can
a qualified lady take the diploma? Any additional in-
formation thankfully received.-G. B. G.

HANNEN.

casualty unfortunately occurred about three years since. [58446.]-Lady Falling on Ice. The above When skating the foot slipped, the lady falling on the elbow of the left arm, which, at the time, was painful, but nothing worth mentioning; but of late it has turned to be very painful, aching from shoulder to palm of hand, where it general y rests for some time. She is unable to when walking) owing to the pain it gives. Two doctors arm by the side (having to support it by the right hand have been seen on the subject, but they fail to do any good. The arm to look at seems pretty right, with the exception of the elbow looking rather red. Hoping some kind reader will take the matter up, any advice will greatly oblige-A. R. R.

being reversed? If so, by what means? Is there any Table.-Will any of your readers be kind enough to carry anything of any weight by that hand, or keep the

cheap work on gas-and-air engines or gas-engine?D. W.

153420.]-Battery.-I use a four-celled bichromate battery for lighting a small incandescent lamp. The porous pots contain solution 7, water 10, bichromate 7, potash i, and sulphuric acid 1. I only use the battery for about half an hour every evening, and I find that on the night I charge the battery, the lamp gives a very good light; but on second night after ch.rging, the light is much duller; and on the third night duller stilleven if I have not used the battery since charging it. I think this is owing to the fluids in the porous pots mixing with the fluids in the outer pots. Can any one tell me a remedy ?-H. B.

[53432.] Everett's Universal Proportion give a description of Everett's Universal Proportion

Table 1-STUDENT.

temporary is a table from July, 1882, to December, 1883, [53447.]-Sunspot Maximum.-In the Congiving the daily average number of sunspots at from 5,000 to 20,000. Will some of your readers who have large estimate such numbers, and give some idea of he sun's telescopes kindly say whether they are able to count or appearance! Occasionally I see 20 or 30 spots with a

[53433.1-Light Railway-Electric Light.Knowing the universal kindness of the friends of "ours," I take the liberty of inquiring as to the "single rail'" railway. It is desired to build a light inexpensive railabout $840 or 35s. a cord to bring it a distance of twentyway for the purpose of hauling wood. It now costs us five miles. I have have seen notes in regard to "s ngle rail" railway but I do not know the principle upon kindly give data s to building, necessary material per which the equilibrium is maintained. Would some one mile, weight of iron per yard, cost of operating, motive (53421.)- Crushed Fingernail.-Last Friday an installation of electric light, both are and incandes-in-J. S. C. power necessary, &c., &c. Also, it is proposed to make got the ends of the second and third fingers of my left cent. There are three mines and one mill; but it would hand crushed between au iron bar (inch square) which was be desirable to place the dynamos at one of the mines resting on the ends and a flat-iron plate. To-day (Tues- and conduct electricity to the others. From this mine, day), the nail of the third finger is deep purple in colour, one is 1.800ft., and the other 4,500ft, the mill 2.500ft. and that of the second dead blue-black, the finger-end The mill is between the two. Can the current be sucbeing swelled to about twice natural size, and of a cessfully conducted so far! It is proposed to have at reddish appearance about root of nail. The pain in both least 20 are lamps of, perhaps, 200-candle power each, bas much abated. I shall be glad if some of your and about 40 Swan or Edison lamps. Taking a Siemens

[58448.]-"Roaring" Harmonium.-I have a harmonium which is a perfect "roarer." It has four rows of reed-, all of which are very loud and harsh, more especially the Hourdon row, which is useless, as it drowns the others, even with the most careful pedalling and the aid of the expression stop. Can a ything be done with the ees to prevent their harshness and buzzing? Or, could four rows of American organ reeds

be inserted in place of old ones, and could they be pur-it does not do if the valves are wrongly adjusted. I note
chased voiced" ready to insert, and at what cost? I am
not skilled in the use of tools. Any assistance will be
appreciated.-CLERICUS.

that the valve for igniting the charges "blows" a little
on the return of the piston, although it is made exactly
to design, and fits fairly well. and I believe the valve
opens enough, I have got a hin. gas supply through a
5-light meter. My gas bag is about 6in. or 7in. long, and
should think the supply-pipe is plenty large enough, but
opens to about 4in. brosd and 3in. deep in middle. I
I am not sure about the meter. As I have tried altering
eccentric valves and everything else that I can think of,
I should feel obliged by any assistance of my fellow-engi-
neers who have been successful in making one of these
little engines go. I may add that however much, or
little, air I allow to mix with the gas, there is no sign
whatever of an explosion. As I believe there are others
in a similar fix to myself, it would be a great assistance
if those who have been successful will give what help
they can as soon as possible.-SMALL GAS ENGINE.
of our kind lathe friends give drawings, with particulars.
[53461.]-Boring Bar for Lathe.-Would some
boring bar for 5in. foot-lathe ?-GASLIGHT.

the materials being gas tar and either whinstone or hard so that an amateur would be able to make for himself a to correspondents, under cover to the Editor, are not for

Well Boring at Burton.-An interesting illustration of the uncertainties of well-boring operations has just occurred at Burton-on-Trent. One of the largest breweries there had occasion to [53-459.]-To Mr. W. J. Lancaster. Though only increase its water supply. Recourse was had to a recent subscriber to the "E. M.," I shall be glad if you boring, and the work was carried out by a local can inform me of the best reversing electric motor and well-sinker. The spot chosen proved an unforbattery to use for my boat 25ft. by 4ft. 6in. (3-horse tunate one, and after a depth of 176ft. had been power engine, &c., is usually used), also the size of motor reached, Messrs. Le Grand and Sutcliff, artesian and number of cells. I do not want to use a battery in well engineers, of London, were consulted as to which sulphuric or nitric acids are the liquids-I thought sal-ammoniac or bichromate. The motor I could not further search for water. This firm having had make, but shall be glad of instructions how to make, considerable experience in well-making operations prepare, and charge the batteries (flat oblong cells if pos- at Burton, advised the abandonment of the boring, sible). Also, information how long a constant current and suggested a fresh site which they selected. would last before recharging, and the cost per hour. I This suggestion was adopted, and at a depth of note your are experimenting with a new form of bichromate of great power and very small compass. This only 114ft. a supply of between 5,000 and 6,000 seems the very thing. Will it be useful to me?-gallons per hour has been obtained from a single

(53190]-Gas-Engine.-Some time since I saw an extract in the "E.M" from a letter to Messrs. Dorrington, stating the success of a gentlemen who had made THE preliminary work in connection with the one of their gas-engines which was working satisfactorily. I should be glad if that gentleman, or any other who has International Electrical Exhibition, to be held at been successful in making his gas engine go, would kindly Philadelphia under the auspices of the Franklin assist me in the following:-I have one of the above- Institute, is progressing very favourably. The connamed firm's engines duly made to instructions; but do tract has been awarded for the erection of a building all I will, it will not go. As I know something about on a site granted by the Pennsylvania Company to other makes of gas-engines. I knew it was necessary to set the slide-valve right. This I think I have done, as I Messrs. Wilson Brothers and Co., of Philadelphia, have made it admit gas and air just as the piston has and will include a main building 283ft. long and started on its outward stroke. No explosion, however, 160ft. wide, with a 60ft. tower at each corner and a takes place, Lowever much I turn the wheel, and I cannot large triangular building joined to the main hall. understand whether it is insufficient supply of gas or a The buildings are to be completed by the 15th of mechanical defect which prevents the engine working. I June, exhibits being received from the 11th to the must explain that I have the gas-jet burning in its proper 30th of August, so that the opening ceremonies can place behind the valve for igniting the charges, and as far as I can see the exhaust opens at the proper time, for be held on the 2nd of September, the exhibition to the engine runs very freely when turned by hand, which remain open until the 11th of October.

The English Mechanic giving a total displacement of about five for the propulsion of launches which do not

tons, was, according to Mr. Yarrow, 69 run too far away from the base of their supknots, or eight miles, the revolutions of the plies. The high speed at which the pro

AND WORLD OF SCIENCE AND ART. motor being 674 per minute. The propeller peller must be driven to obtain even such a

FRIDAY, APRIL 18, 1884.

is 24in. diameter, with a pitch of 13in., and speed as eight miles is notable, and is not Mr. Yarrow thinks that if it had been de- without interest in connection with vibration signed to make a less number of revolutions in steam-vessels, a subject which is not altoELECTRICAL PROPULSION, VIBRA- for the eight miles, it must be remembered, confessedly very much of a puzzle. the efficiency would have come out better, gether understood by experts; in fact, it is TION, AND STABILITY OF SHIPS. Mr. was accomplished with the tide. Each cell, Otto Schlick read a paper in which AMONGST the more interesting papers it is stated, is equivalent to about one horse- the subject is considered at length, read at the recent meeting of the In- power for an hour developed on the shaft, and in which he shows that the vibrastitution of Naval Architests were those but in practice Mr. Yarrow finds that a con- tion depends on the isochronism of the. relating to electric propulsion, the vibration, siderable reduction must be made, and it vessel's vibrating period with that of the and the stability of ships, the latter sub- would probably be safe to reckon only about disturbing forces set up by the engine. The ject having produced no fewer than seven one half that amount. Mr. Reckenzaun stated most important of these forces are the papers, in consequence, no doubt, of the that with a weight of 2lb. of motive ma- forward thrust, the turning couple of the disasters to the Austral and the Daphne, and chinery, including shafting and propeller, engine, the sideward the suspicions aroused as to the cause of loss one horse-power could be exerted on the propeller, the pressure of the reciprocating pressure of the in vessels that have sailed from port and shaft for one minute, therefore 840lb. would masses, and the pressure of the rotating never been heard of again. The electrical be required to drive a boat requiring one masses when the position of their centre of launch formed the text of Mr. Yarrow's horse-power for seven hours. That method gravity is out of the middle. Mr. Schlick paper, and gave rise to a discussion on the of looking at the question is simply a little thinks that the three last-named forces are probable future of electric propulsion. We exercise with figures, and is utterly useless, those which produce the shaking; but all have given a description of the launch in for 21b. weight of machinery will not drive the forces are capable of setting up vibraquestion (see p. 441, Vol. XXXVIII.); but a launch, or anything else, for a minute or tions in the more or less elastic hull. In a the figures now brought forward are sup- any other period of time. The use of such weakly constructed vessel, where the mass plied by Mr. Yarrow, and may be taken as figures, legitimate enough in one way, only is great and the elasticity of the hull small, correct, though for some he is dependent on helps to cloud a question which is of very the vibrations are of considerable duration, the Electric Storage Company and on great interest, and which should be dealt and the extremities swing in a slow meaMessrs. Siemens Bros. The launch is 40ft. with from a practical point of view at once. long, 6ft. wide, and weighs two tons. The The motive machinery used in the launch mass small the vibrations will be rapid. It sure; but if the elasticity is great and the storage cells employed weighed altogether referred to weighs, as we have stated, 10cwt., is not necessary for the production of strong 40 cwt., and the weight of the machinery is and the cells to supply the power weigh a vibrations that their period and the revolu10cwt., giving a total of, say, 4 tons. The little more than two tons. To talk, then, tions of the engine should coincide; it is storage cells are of the Faure-Sellon- of 21b. giving a horse-power for a minute is sufficient that one should be a multiple of Volckmar type, each containing eighteen simply misleading, and is utterly beside the the other. Mr. Schlick suggested methods pairs of plates. The positives are coated question. The fact is that a boat weighing of preventing vibration, the most feasible of with red lead, and the negatives with with its accumulators and propelling ma- which seems the shifting of the propeller on litharge. In the course of forming the red chinery four tons and a half was able to run the shaft relatively to the cranks; but so lead becomes peroxide, while the litharge is in practically smooth water at the rate of little is known of the matter that it is clear reduced to the spongy state of lead. The eight miles an hour with the tide. The ob- experiments must be made on the individual liquid used is sulphuric acid and water injections to the use of electricity, or at least ship. Mr. Denny, of Dumbarton, said the the proportion of 1 to 4. The action is electricity in the form of the secondary thanks of the meeting were due to the tolerably well understood, from the frequent battery, are the difficulty and delay occa- author of the paper for the manner in which descriptions that have been given; but it sioned by the necessity for frequent charg- he had treated an important subject. His may be doubted whether it is quite correct ing, the greater first cost, and the greater firm had made many experiments as to the to say that the plates after giving out elec- cost of working; but there are some others best manner of strengthening the heel of a tricity are in exactly the same state as which specially militate against the use of vessel, and he described a few of the devices they were prior to being charged. electricity in torpedo boats, or in anything adopted. Mr. Yarrow gave an account of a That, however, is a detail-an im- but pleasure boats used on smooth water. practical experiment made on a torpedo portant one when the durability of Mr. W. H. White said that he had gone into boat with the propeller removed. With the the cells comes to be considered, but which the matter a year ago, and arrived at the engines running at 200 revolutions there can be put aside for the present, the im- conclusion that it is not practicable to apply was vibration, at 300 none; at 400 it was portant point is the economy to be obtained electricity to a second-class torpedo boat; very heavy, and at 500 there was none by the use of electricity. An average of the but Mr. Morgan thinks that if storage again. At 600 it returned, at 700 ceased; estimates gives a loss of 15 per cent. between batteries can be used in pinnaces and cutters but at 800 revolutions, the highest rate attainthe engine and the dynamo, leaving 85 per carrying spar torpedoes an immense advant- able, it was very severe, facts which appear to cent. of the total mechanical energy of the age would be gained in the aggressive power show that the action of the propeller on the engine; the loss in passing the electricity of the latter, but he stipulates for a speed water has very little to do with vibration. into the accumulators is 10 per cent. of that, of nine knots, and overlooks the fact that Mr. White also instanced the famous trials and the loss incurred by converting the rough water would materially affect the of the Iris, during which at 14 knots, there stored electric energy back again to mechani- estimate if the present form of storage cell was little, if any, vibration, while at 16 cal energy is 25 per cent. of the last total, is to be used. Admiral Selwyn stated that knots it was considerable, and at 18 knots, so that there is an estimated residue of 57 it was possible to obtain a storage battery the highest speed, it again disappeared. per cent. From his own observations Mr. weighing 55lb. which would yield one indi- Mr. Yarrow and Mr. Samuda also spoke of Yarrow thinks that from 45 to 50 per cent. cated horse-power for 10 hours, at a cost of similar effects in connection with light of the power required to charge the cells only £3 and last for 10 years! We have draught and stern wheel steamers, in which may be relied upon as available for pro- no notion how he has arrived at the dura- there seemed to be one or two speeds at pelling the launch, so that at least half the bility of this wonderful cell, which he said which vibration was reduced to a minimum, power of the steam-engine is lost. To comwas Mr. Spagnoletti's; but we know very while at others it was so excessive that if pensate for that, however, it must be remem- well that if it can do what he says, which allowed to continue it would shake the vessel bered that by keeping the steam engine and he repeated when asked, it is the most to pieces. The stability of vessels is another boiler out of the launch the whole capacity wonderful cell in existence, and would be point of very great importance, and a variety of the boat is available for seating passengers, bought by the thousand if such a perform- of opinions on the subject were expressed there is an absence of noise and risk of ex-ance could be guaranteed, for, as Mr. Recken- by the authors of the papers and those who plosion, and great cleanliness, to say nothing zaun pointed out, it is about 800 per cent. took part in the discussion, the most sinof comfort and pleasure. The motor sup- better than anything known to electricians. gular of which was perhaps the astounding plied by Messrs. Siemens is capable of Mr. Yarrow's figures are no doubt approxi- assertion that the present race of shipworking up to 8 or 9 h.p., but probably it mately correct, and they show that it is im- captains were unable to understand curves has never given out more than 7 h.p., and possible to get more than about 50 per cent. of stability. when a continuous run is attempted the of the power originally employed to charge do not, for the simple reason that it has It may be conceded that they power soon falls off, the reduction in speed the cells. The theoretical energy in a pound never been their duty to endeavour to combeing about half a knot per hour during the of lead is 360,000 foot-pounds, but in practice prehend the jargon of the naval architects; first three hours. To meet that difficulty only about 33,000 foot-pounds can be ob- but Mr. Gray made the matter worse when the full power is not used at first, but a tained. certain proportion of the cells is reserved to battery, and utilise a large percentage of due to the use of hard names such as "metaIf some one can devise an iron he suggested that much of the difficulty was be coupled up as may be required; but even the theoretical million and a half foot- centre." Mr. Denny, who read a paper on then the launch cannot be kept at work for pounds per pound of metal, there would no the subject, stated that his firm were premore than six or seven hours. The best longer be any question as to the success of paring for one of the vessels now building result obtained with six persons on board, the storage battery as the reservoir of power a small volume, in which all the particulars VOL. XXXIX,-NO. 995,

having reference to the safe working and profitable occupation of the ship would be set forth, for the use of the owner and the master. He had originally intended supplying the curves of stability; but after learning the opinions of Prof. Elgar he had decided not to do so. More than one speaker referred to the alteration in the stability of a steamer as her coals are consumed, and Mr. Martell, of Lloyd's, took the opportunity to point out that excessive stability obtained by increasing beam at the expense of depth was likely to prove as dangerous as defective stability. In all these points, however, there is no sign of a suspicion that steam is likely to be superseded by electricity, although the use of the storage battery would at once place in the hands of those concerned a means of avoiding much of the vibration and of securing all the stability desired. The reason is obvious, for it is the simple fact that it is cheaper to carry engines, boilers, and coals, than a dead weight of lead and acid sufficient to propel the vessel to her destination. In other words, the 50 per cent. loss incurred by the use of accumulators more than compensates for the loss of cargo capacity in the space occupied by the machinery and fuel, and, for the present, electrically propelled vessels will be confined to short distances within the limits of which they can be readily recharged at the least expense.

PRACTICAL NOTES ON PLUMBING.-
XCIX.*

By P. J. DAVIES, H.M.A.S.P., &c.

(Continued from p. 115.)

Fixing or Fitting up.

LET us now look over the section of a house be emptied at any of the draw-off cocks, and which has been fitted up on one of the therefore will be the best system to adopt (should most approved principles. For this refer to the water supply fall short through frost, &c.), Fig. 463. Here we have a close kitchener, because there will always be a good supply to marked 45 and 46, with boiler at back, as shown keep the boiler from becoming dry. Some at Figs. 436 and 440. P is the cold water or plumbers use a dead weight or other safety valve return pipe, bringing the cold water from the on the top of the boiler or tank to open should bottom of the circulating tank to the bottom of there be any extra pressure accumulated within

the boiler.

In this case the HOT WATER TANK is fitted at the bottom of the house and near to the

the boiler or tank.

R

Sink 5

Top Bath Waste Pipe

of good white hard varnish, which can be pro cured of any oilman. The two should be well incorporated together by working with the brush intended to be used for laying on the varnish.

The varnish should be applied in a thin layer with a soft brush, so as to disturb the paraffin coating as little as possible, since if the paraffin mixes with the varnish, this latter never dries, but remains a sticky mess. For this reason, the coating of varnish should be allowed to dry without the application of heat, which, if the "white

kitchener. This often saves a long length of THE DYNAMO: HOW MADE AND hard" be good, it will do in about 8 to 12 hours.

pipe. The cold water supply pipe LMN is brought right away from the top tank, and as shown with a stopcock at M, and also a trap to prevent the hot water rising through this

supply pipe. But notice if the hot-water tank

is above the bath as marked by the dotted lines at 36, and if the cold supply pipe to bath, &c., as at 4 is, as shown, taken off the pipe N, then you will be likely to get hot water into your cold when drawing, especially if any part of the pipe between the cold-water cistern and branch be cramped, or a Rotherham stopcock fixed thereon, unless the return of the hot water be properly checked with a proper check valve, which may be an ordinary screwed for iron spindle valve. In fact, when the hot-water tank is fixed above a cold draw-off cock, then no draw off should be allowed to be taken off the cold water supply pipe to the hot-water tank; that is, if the tank is fixed at a higher level. The coldwater pipe 4 in that case should be run from AQ to A K, and branched on at this point, or brought direct from the cold-water cistern. But if the cold-water pipe N M is properly trapped, and then taken direct into the return pipe at the nearest point to the boiler, or still better direct into the boiler, and this pipe together with all stop cocks, and other water passages larger than the draw off, then the chances will be that you will not get hot water with the cold. I is the air or steam pipe taken to the top of the house. The hot water supply pipe H to the best bath is with a Tee taken off this air pipe, also the hotwater pipe I, J, K, Q, R, A B, and G to supply the washbasin, scullery sink, servants' bath, &c. In this section may be learnt the whole system of hot-water work. By reference to the manner

in which the draw-off pipes are taken off the top varnish. The best for this purpose is made by part of the tank, it will be plain that it cannot mixing about 2oz. of the best red lead, with to

A second coat may be given if desired; but as this generally fills up the interstices between the layers of wire, it detracts somewhat from the neatness of the appearance.

§ 37. The varnish being quite dry, the dynamo may again be put together, care being taken ther the parts are adjusted in the position which they occupied after fitting. If this has been properly done the armature ought to turn freely in