well indeed without any shade of colour appearing. The planet Jupiter, would, I think, appear nearly the same size as in the 4in. Gregorian, but then the defining power and brightness of Gregorians as compared with refractors is stated by Dawes as 8: 5, that is the proportion of aperture, both telescopes being alike in brightness. As a light test, I am able with 75 to pick up the 7 mag. companion to Antares; Warner with the finest instruments could only do so with 23in. distant 3. I am also able to see two of Saturn's moons, and the ring very fine. When Venus was an evening star, I could observe her with the 150 power without the slightest trace of colour, and to those who know the difficult object she is in the telescope, that is a testimonial of the performance of the glass. The Messrs. Solomon supply the 3in. glass separate by itself, price £2 28., and any power eyepiece 148. For the information of all your readers, I have found by trial during the last few weeks, that the sun had so many spots on his disc that green and red glass combined made the best shade, much better than either above. To those who have not got the " Nautical Almanace," to see the sidereal time time at noon, I may tell them that they can get it by applying the equation of time to the Sun's. (R.A., the reverse of that directed in the almanac pages.

[2236.]-DIRTY CEILING.-All common plaster is pervious to air, which, in passing through it, is, as it were, filtered from the dust which floats in it. Where most air passes most dust is left, and so those portions of a ceiling where the passage of air is not impeded by joists, &c., collect most dust and are most discoloured. -J. B.

(2237.)-SALERATUS.-"A carbonate of potass, containing a greater quantity of carbonic acid than pearl used in cookery."—"Ogilvie, Imper. Dict."

ash;

H. B. M.

[2239.]-PROTRACTOR-The fault lies in the protractor, and not in R. W. R." A protractor, properly constructed, should have a mark, either on the upper or the lower edge of the cross-piece; which, of course, depends on the construction of the instrument. On his instrument, the mark should be on the lower edge of the cross-piece; also the mark for 10, and that for 1800, should be in the same straight line with the centre mark, otherwise the protractor is not properly divided Any mathematical instrument maker will put a centre mark on it for him.-THOMAS J. O'CONNOR.

[2248]-SPEED OF AIR AND STEAM-To calculate the velocity of air or steam rushing into a vacuum, we must first find the height of a column of air or steam corresponding to the given pressure. Then from the rule for falling bodies we must obtain the speed due to that height, which will be the theoretical velocity of the gas on vapour. When the steam issues from an orifice into the open air, we must deduct the pressure of the atmosphere from that of the steam, and then find the height of a column of steam corresponding to the resulting pressure, and proceed as before For instance, the velocity of steam at 15lb. pressure rushing into a vacuum, would be same as that of steam of 30lb. pressure rushing into the atmosphere.MACHINATOR.

1

16

[2302]-POLISHING SCOTC H PEBBLES.-Lapidary mills, &c., on a small scale, for amateurs, may be had in and about Clerkenwell, eit her new or secondhand. Advertise in the ENGLISH MECHANIC, or consult Vols. VIII, IX., and X., for directions how to make the tools.-ENGRAVER.

you have formed a strong tube at least in. thick,
and then thoroughly cont with the shellac several
times, and allow it to dry. To shut out all communica
tion between the primary and secondary coils, it will
vulcanite ends by means of several thicknesses of gutta
be as well to secure the edges of the paper to the
percha tissue cemented by a hot knife, as the insula-
tion is all important, This done, take the secondary
wire and test it on the ree by means of a galvanometer,
and if the needle shows that the wire is unbroken,
you may take one end, and, passing it through the
small hole before-mentioned, commence winding it on
When
carefully and closely to nearly the other end.
and spirit three or four times, and allow it to dry
one row is finished, carefully varnish it with the shellac
thoroughly, then wrap round several thicknesses of
gutta percha tissue, and one thickness of paper soaked
either in the aforesaid shellac mixture, or a warm mix-ner's "Cyclopædia."-PATER.
ture of gutta percha, benzole, and paraffin. You can
then proceed with the next row, and so on, till you
have filled your reel and bobbin to the edge, or nearly
so. The one great thing to guard is the insulation,
and of that it is better to have too much than too
little.-T. S. CONISBEE.

[2309.]-ETCHING ON GLASS has been so fre

quently described in the ENGLISH MECHANIC that I should not like to occupy valuable space with it; besides, it is an unhealthy business. Draw your design as you would on metal, and give the plate to a professed dipper, who will use the hydrofluoric acid instead of the fluor spar. But after all, the effects are not to be compared to those produced by the diamond poiut, or the engraving lathe.-ENGRAVER.

[2267]-WORK ON ELECTRICITY.-I would recommend the work on electricity published by Messrs. W. and R. Chambers, Paternoster-row, price, I think, about 6s., as a very good and comprehensive work on electricity, both theoretical and practical.-T. S. CONISBEE.

[2267]-ELECTRICAL BOOKS.-"S. T. P." might get Dyer's "Induction Coil," price 18., or Noad's "Inductorium." 38., I think, on that special subject. For general details in electricity. "The Student's Text Book," though a rather slip-slop compilation, is a useful book at 12s. 6d. ; but for simplicity and scientific accuracy there is no work superior in a small way to Ferguson's Electricity," at 38. Cd., but it does not go fully into any branch.-SIGMA. [2268-POLES OF MAGNETS.-"H.'s" question arises from a common misapprehension. The poles are not the points of strongest action merely, but the points at which are united the actions of the half magnet as a whole, and from which the relations of the force to distance are to be considered; they bear thus a sort of analogy to the centre of gravity of a body; which is not necessarily the heaviest part: form and arrangement influence the position, as also does the presence of another magnet. The points of maximum attraction are at the extremities, because each section of the magpet has its own power, and transmits it to that beyond; but the action on a body separated the extremity, but from the pole, which explains the from it will vary according to its distance, not from by no means quite clear law of the square of the distance. Thus, at lin., the force may be very much greater than one-fourth that at in.. and if the pole were lin. within the magnet, the body would have to be removed to 3in. to reduce the force to one-fourth that at in. distance.-SIGMA. CURRENTS. An ordinary fine wire instrument, well [2272.) - GALVANOMETER FOR INDUCED insulated, will do, but it must be used differently from [2251.]-DISPENSING QUERY-By altering the usual, as the induced current is instantaneous only, and mixture it can be made perfectly clear, not without.-attended with a reverse current at each contact; hence only the utmost swing of the needle produced by a single make or break of contact can be used, and as the intensity and not quantity is the characteristic of these currents, to get any valuable information would require a series of resistances as well as a galvanometer. Of course, if great care be not taken in the insulation of the instruments while making, they would be apt to be destroyed by a spark of high tension.-SIGMA. [2283.]-PAINTING THEATRICAL SCENES."H. N. H." asks how to paint theatrical scenes on coarse calico with water colours. The thing is easy enough. The calico must be stretched on a frame, and coated once with clean size. When it is dry, the scene must be sketched with a soft crayon or blacklead can be obtained at any oil and colour shop. They must be mixed with warm size, and, when first put on the canvas, should appear much darker than the tint that is required. Different from painting in oil, the first coat of colour must be the final one; the size will then not peel off when the canvas is rolled up. Νο varnish is required.—HIPPArchus.

GUILLAUME.

(2258.]-EQUATIONS.-Mr. Williams will find a solution by "Senior Op." of the treble equation in last number. The following solutions of his other equstions are suggested:

Here

t - a

- b

+

= 0

x = a, y = b

(1)

(2)

-

evidently satisfy (1), and by trial they are found to pencil. The colours to be used are all earths, and they

[2262.]—RHUMKORF'S COIL.-Having provided a bobbin of paper, wood, or vulcanite, with (by preference) vulcanite ends, drill two holes in one of the ends, each about fin, diameter, and at a short distance from the centre. These should be in a line with the horizontal diameter of the bobbin tube. In the opposite end drill a small hole-say-in. diameter, at a rather greater distance from the tube than the others, but this time over the tube. Next take your primary wire and pass one of the ends through one of the first-named holes, and wind it over the tube in a close spiral quite up to the other end, continuing to wind it back again over the first layer to the end at which you first commenced, and passing the other end of the wire out through the remaining large hole first mentioned. When this primary coil is completed, give two or three coats of shellac dissolved in methy fated spirits, and allow it to dry thoroughly. Next take a strip of cartridge paper the exact width of the bobbin between the ends, and wind it on tightly until

[2288.-CHARCOAL for rubbing down silver circles may be obtained at most of the good tool shops; it should be carefully tried first on an old plate; to prevent the risk of scratching good new work. - ENGRAVER.

[2291]-ENGRAVING ON METAL.-The point is used for tracing the outline, the scraper for removing the rough burr made by the graver. I really do not know any rule for tempering the graver; metals vary so much in toughness and hardness that practice alone is the sure guide. -ENGRAVER.

[2296.]-MONOGRAM DIE.-If a copper counterpart be necessary, take a cast and copper it by the electro process. To touch up any imperfections, a graver and a seal engraver's lathe are the tools.-EN

GRAVER.

[2299.]-GENERATION OF ELECTRICITY.-I can scarcely give "Lancashire Lad" the information he asks, not being sufficiently acquainted with the arrange ment of the machinery. I suspect that the threads must rub against some dry surface of wood, or other insulating substance, or, possibly, guttapercha belting is used, and works on a wooden pulley. The best suggestion I can give is to fix pointed wires near to the parts at which sparks are apt to be given off, and as close as possible, and connect them to the nearest gas and water pipes. One wire will serve to connect many points. If gutta-percha is used present leaves the pulleys. Will the queriet, if he tries this, a comb of points thus to it at the part at which it say if it succeeds?-SIGMA.

[2312]-HISTORY OF IRELAND.-" History of Ireland, from the Earliest Times to its Last Chief," by Thomas Moore, 4 vols, 8vo, 24s., is contained in Lard

[2318.] ETHERIAL SOLUTION OF GOLD. — B. S. Burden could get this prepared by any chemist, as druggists are usually called; or prepare it by dissolving chloride of gold in ether. The chloride he would obtain of any photographic apparatus dealer, or make by dissolving gold in aqua regia, or hydrochloric and nitric acids, evaporating to perfect dryness and redissolving in water, and again evaporating till all the water is driven off.-SIGMA.

[2323.]-WATER POWER.-If "G. P." can dam up the stream of 200 cubic feet per minute, so as to obtain Sft. clear fall, the power obtained will be 3 h.p.; and deducting one-third for friction and loss, there will remain a useful power of 2 h.p.-C. S.

[2333]- BRILLANTINE. - Glycerine, 1oz.: oil of almonds, 2oz.; oil of jasamin, 1oz.; mix, and shake well.-W. C.

[2348]-ELECTROTYPE.-If "E. R. H.'s" objects are sufficiently large he would get a better result by using hollow moulds and depositing within them, but this might be very troublesome, as the moulds might have to be made in several parts in order to remove them from the model: moderately small objects may be thus copied by careful arrangement of pieces of copper within the mould, but of course not in contact with it.-SIGMA.

[2352.]-OVALS.-The best directions I ever met with for describing ovoid figures are contained in a work by D. R. Hay, "On Symmetrical Beauty," Svo., Blackwood and Co., 68, to whose writings I acknowledge my great indebtedness. Illustrated directions for drawing ovals have been given repeatedly in the ENGLISH MECHANIC. Why does not every subscriber purchase the indexes to back volumes ?-ENGRAVER.

[2356.-GOLD.-" Rudis" may use either of the following processes to recover his gold :-First mix about 1oz. of mercury (comnion quicksilver) with the mixture, and well shake for some time; allow it to settle, remove the sand and drive off the mercury by heat in a crucible; the gold will be left behind. Or be may add a mixture of nitric and hydrochloric acids, and allow the whole to stand; he will then have a boil the whole till the gold has entirely disappeared, solution of chloride of gold, which can be poured off, leaving the sand as a sediment. By mixing the solution with water and mixing with a solution of sulphate of iron, the gold will be recovered in the metallic state as an impalpable power, which, from its neness, will appear as a fine chocolate brown. The latter way, although very troublesome, will yield the gold chemically pure.-T. S. CONISBEE.

[2361.]-SOFT SOAP MAKING.-In 1441 "Thackeley Lad" gives a recipe: 10lb. of potash in warm water over night, in the morning boil it, adding 61b. of grease, then 15 gallons of warm water. I used the best tallow and have failed in soap making, so if information it will be thankfully received.-A CON"Thackeley Lad" or any other reader will give more STANT READER.

[2362.]-METALLURGY OF COPPER,-Mr.Joseph interested me much. Is there in London any metalRoskell's articles on the metallurgy of copper assist at the operations he has so well described ?— lurgic establishment where I should be admitted to

E. V. D. S.

[2363.]-SILVERING CLOCK DIALS. - I know there have been many recipes given for silvering brass, some I have tried, but ineffectually. Surely some of our London or Birmingham readers could give me a cheap and simple recipe that I should succeed with. It is waste of time, money, and patience to keep trying recipes and fail.-POOR CLOCKJOBBER. [Has it ever occurred to "l'oor Clockjobber that possibly the fault might not be in the recipe, but in the way he applied it ?-ED. E. M.]

[2364.]-TIME. In the article on "Time," by "F.R.A.S.," No. 260. p. 618, Vol. X., he says if we bisect the interval S S' thus measured on our meridian line at E, we shall only have to wait until the shadow of the top of our rod G just touches this point E of bisection to ascertain the days of the two Equinoxes, because, to cast a shadow of this precise length, the sun must be on the equator. It is not so, for the shadow of the rod G at the days of the Equinoxes does not cover half of the above-measured meridian line. "F.R.A.S." explain this ?-W. F. SWALLOW. [2365.]-GREASE.-Will "Patience and Perseverance" be kind enough to explain more fully what is meant by caustic or milk lime, and how made, and what quantity he would use of one to the other, as I hard enough? I find the recipe on p. 589, Vol. X, have tried many ways, but failed to make the grease

Feb. 25.-A LONG LOOKER.

Will

32

[2366]-COPPER BOILER. -I purpose having a 3 small boiler made out of sheet copper-in. thick, it has to be 2ft. long and 1ft. diameter. Will some of my brother readers kindly inform me as to what pressure it will be safe to work it, and what power it will drive? -CAUTION.

[2367]-ANILINE COLOURS FADING.-I wish to colour the windows in my stock room to prevent goods which are made from cotton and woollen yarns dyed with aniline colours, fading. Can any brother reader say from practical experience which is the best colour for the purpose? It must be rather transparent, allowing a moderate amount of light to pass through.-W. H. F.

(2368.]-CUTTING AND POLISHING STONES.If you or any of your numerous readers could give a description of the process from first to last, I think it would be greatly beneficial to many of our lapidist

friends-it would be to me, at least.-LAPIDIST.

[2369.]-COLLEGE OF PRECEPTORS.-Will some. one give me some information respecting the College of Preceptors?-when was it established? what are It objects? and how can anyone become a member?. S. KENT.

[2370.]— UNSOLVED PROBLEMS. Would the author of "Unsolved Problems" kindly assist me in the following?-If the piston rod of a steam engine, say 1-horse power, was suitably connected to the rim of the fly-wheel, what saving of power would result? Would it increase the power of the engine? I bave invented the means of doing so; have made a rough model in woed of a horizontal engine about 4in. to 1ft., and it works very smoothly by pressure of the hand on piston rod; it appears to me to be equal to a crank of half the diameter of wheel of a stationary engine.-J. BANNELL.

[2371]-HEATING OF JOURNALS.-I am very much annoyed with a bell (or double) crank and other journals heating, although lubricated with the best sperm oil. Is there any thing which I can apply to keep them cold, or cool them whilst running, with

out having to stop the engines to do so?-RELWOT.
[2372]-WIND INSTRUMENTS.-Can any of your
numerous correspondents enlighten me in the theory of
making wind instruments, such as fifes, &c.? What rules
have they for the places, and sizes of the holes for the
finger and keys ?-SIGISMOND.

[2373.]-STENCILLING on GLASS-I shall feel much obliged by instructions as to the best method to be pursued for stencilling large numbers of sheets of glass about 18in. by 8in., with explanation of the best kind of utensils, &c.; also the address of a maker who supplies the necessary apparatus and tools for the above process, and who supplies the stone and metal wheels used for putting patterns or lines on glass. Does any correspondent know the process used in Germany for the manufacture of paper table napkins, toilet covers, and cloths? It is not an ordinary paper mill, as the material is so treated that it can be rolled out either by itself or on to linen, and is, when dry, quite tough. Any information I shall be glad of.S. D. T., 6, Mildmay Park, N.

[2374.1-BREWING.-Where can I get a good treatise ou brewing ?-NEW SUBSCRIBER.

[2375.]-LIFTING SACKS.-I shall feel greatly obliged to any of your readers or correspondents who will give me a practical idea for enabling sacks of corn to be lifted from the ground to a height of 3ft or 4ft. by one man's labour. In the course of the year we have to move from our barn floor into a cart or waggon some seven or eight hundred sacks, and I wish to do this with two men only-one to lift the sacks, and one in the cart. Our present mode is to back the cart to the barn door, and then for the men to lift the sack by main force into the cart to the third man. But I imagine some simple mechanical contrivance would enable one man to do this. At first I thought of fixing a pulley to the beam above the barn door, and running a rope through by which to hoist the sacks, but as the sacks weigh 25 lb., and a man about 170lb., it would obviously require a system of pulleys to effect the required lift. It has also occurred to me that an inclined plane from the barn floor to the cart might be made effectual, but as I am not mechanic enough to carry this out, I think it better to state my difficulty, and trust to the ingenuity of your correspondents to offer a solution. Economy, both of labour and material, is indispensably necessary.-RUSTICUS.

[2376.]-GEOMETRY. Represent three planes, each perpendicular to the other two, when two of them are inclined at 50° to 70° to the paper. Show the inclination of the third plane.-A TEACHER. (2377)-GOVERNORS.-Which governor for controlling engines may be relied on as the most sensitive?

-CLAUDE.

[2384.]-WORK ON ELECTRICITY.-Will someone of your readers (perhaps "Sigma ") be so good as to recommend me a good modern work on electricity giving price) describing the theory of the induction coil? If not in English, a work in German or French would suit.-S. T. P.

-I. H.

[2385.1-HARMONIUM TONGUE-RIVETS.-Can
rivets can be procured? Application has been made
some of our provincial friends state where these said
to several houses in the metropolis to know if they
can supply them, but the reply is uo. You may pur-
chase any amount of tongues, but not rivets in London.
[2386.]-TUNING HARMONIUM REEDS. - I am
very glad to see the renewal of Mr. Hermann Smith's
papers on harmoniums, and will be obliged to him if
he will state whether in tuning harmonium reeds the
action has to be opened and shut every time a reed is
scraped? Is there no other method of trying whether
they are in tune ?-VIBRATOR.

inform me how to make a shower bath at a trifling
[2387]-SHOWER BATH.-Could any subscriber
expense, as I cannot afford to buy one?-T. A.
[2388.]-UNANSWERED QUERY-Will some kind
friend favour me by describing the material used in
solution to deposit a blue and red surface on tinsel
plate or flattened wire-such as is used for fire stove
ornaments, and by fishing tackle makers, and if it is
deposited by a battery, and if used hot or cold?-IN-
QUIRING WORKMAN.

[2389.]-VARNISHING GILT MOULDINGS.-I
have heard that there is a process or means of
varnishing gilt mouldings so as to prevent the gilt
from rubbing off when cleaned or dusted; if such be
the case, I shall feel extremely obliged to any of your
numerous intelligent correspondents for information
on the subject.-DESIDERATUM.

[2390.]-INDUCTION COIL.-Will some brother
reader kindly tell me what battery power I can safely
use with a coil of the following dimensions ?-Primary
wire, 54f, wound on in four layers; secondary wire,
3168ft., wound on in thirteen layers? The large wire
weighs 11b., and the small (No. 39), lb.-THOMAS J.
O'CONNOR.

reader of our valuable paper, kindly tell me the best
[2391.]-GAS STOVE.-Would "J. B.." or any
form of gas stove and burner for heating the water to
nearly boiling in a coil of in. iron pipe 36ft. long, and
the time it would take to heat the water?-ROBT.

scientific contributors oblige by giving the process for
[2392-WRITING ON GLASS.-Would any of our
embossing the name, &c., on glass bottles-such as you
see on publicans' bottles in the form of a lable, the
letters being clear, and the ground embossed ?-JE NE

SAI PAS.

[2293.]-NICOTINE.-I should be glad if someone could inform me if there is any non-poisonous liquor that will absorb nicotine.-MAUES.

[2394.]-WINDMILL.-Would Mr. H. Algar be kind enough to explain the plan (described on p 560, Vol. X.) he has for regulating the mill in accordance with the power of the wind, and if the sails be wood or sheet iron, and what length the arms would require to be to have power to drive a thrashing machine?[2395.]-CANARY CAGE.-Can any correspondent inform me how to give the wire of a cage a silvery appearance?-AVIARY.

C. C. J.

I then tried one three-pint cell of the manganese bat-
tery and that also took no effect. Will W. H. S.
tell me the number of cells I should require to make
it equivalent to two cells of Smee, and what is the
best size wire to use in the construction of bells? Any
information I shall be glad of.-A. SPENCER.
[2403.]-FLUXES.-Will Mr. Roskell or Mr. Davis
kindly inform me where to obtain fluor spar, and can
it be obtained in a powdered state? Also what is white
argol, as I cannot find in Park's "Treatise on Chemis-
try," any mention of it? I presume it to be a mineral
substance to be used as a flux.-DORSET.

--

[2404.] TELESCOPE QUERIES. Would Mr. Blacklock kindly say if he can use a power of 500 or 600-which his 6in. speculum ought to bear under favourable circumstances-without screw motion in azimuth? Mr. Peters would also oblige very much by a description of his fine screw motion in azimuth. I am thinking about setting up a reflector, and like Peters-chiefly through his stand having screw the plans of both the above gentlemen, especially Mr. motions in each direction. Have any of your readers compered or tested Mr. Purkiss's specula against Mr. With's? The prices of the former are so gloriously low compared with the latter, that I hardly dare hope for results so good as those obtained from the WithBrowning specula.-C. S.

[2405.] MANGANESE BATTERY. TO MR. STONE.-I duly appreciate the valuable service Mr. Stone has rendered to your readers in bringing the manganese battery so comprehensively before them. I was to describe a cell which acted so perfectly. I use am sorry he should feel it necessary to deprecate the information I have given, but my object in doing 80 uncovered copper wire (No. 17 gauge) insulated at the supports through a piece of india-rubber piping, and the thickness of the wire is, I am told, rather a disadvantage. I have, since Mr. Stone's last communication, fitted up a quart cell according to the dimensions he there gives, but I exceeded his estimate of 23. 8d. for a quart cell, as I had to buy binding screw and platinum foil. This sized cell works my bell very well, but the ring is not quite so powerful. I intend to use the cells alternately-a week each. Will Mr. Stoue kindly say whether they will gain much in power by this interval of rest? I should also feel obliged if Mr. Stone would state how the binding screws and platinum can be dispensed with, as they form no inconsiderable item in fitting up three or four cells.E. H. B.

[2406.]-MANGANESE BATTERIES.-I am about to construct some manganese batteries, but before commencing, would like to know what surface of zine should be exposed to the carbon, so as to obtain the greatest power? Of course the more zinc the longer it will last but is there any method of getting at the proper proportion that should be exposed of each. I also thought of constructing a single fluid battery of carbon and zinc, to be charged with a saturated solution of salt and water. Has such a battery been tried, if so, what are its merits? Will " Sigma" kindly answer the above ?-E. C. MURRAY. form me of a book showing how to obtain different [2407.]-COLOURS.-Could any fellow reader inshades of colours from chemical dyes-as fustic, prussiate, potash, &c.?-MORDANT.

[2408.]-METRONOME-Would some reader give iilustrations and description of a clock metronome ?METRONOME.

[2409.] MENDING TORTOISESHELL. Will ornaments ?-A. S. C. someone explain the process of mending tortoiseshell

[2410.]-PEDAL PIPES.-I am building a chamber organ (6 stops), the stopped diapason is the only one I tenor C. As I intend having a separate pedal organ, am carrying through, the others only extending to would any of your readers inform me what scale of pipes they would advise for the pedals-whether a bourdon or a 4ft. stopped (large scale), or a principal? Perhaps "An Adept" would kindly answer my query. The organ is to be more particularly for fugue playing, to contain the following steps:-Open diapason, 42 notes; stopped diapason, 54; dulclang, 42; principal, 42; twelfth, 42; fifteenth, 42.-GEO. M. LITTLE.

(2396.]-CHAMBER MUSIC.-As we cut the leaves
of the MECHANIC and stitch it for dad's perusal, we
always get a peep at the contents, and are much
pleased with the drawing lessous now publishing. We
should be thankful if Dr. Ussher, the "Harmonious
Blacksmith," or any of your musical readers would
recommend some good trios for violin, English
concertina, and cello. Also a few slow movements as
quartetts for the piano, and the above-named instru-J. Jarman, of Ramsgate, oblige with a description of
[2412)-MANGANESE BATTERY.-Will Mr. A.

ments.-OPHELIA AND ALMA.
[2397.] HARMONIUM.
I have an excellent
harmonium by Alexandre, with two rows of vibrators
one of 8ft., the other 16ft.. it has this defect, viz.,
when I pull out the stop grandjeu, the wind seems to
run, and it is with difficulty I can sufficiently supply
it, even by hard blowing, otherwise it is in excellent
order. Will some kind subscriber point out the cause,
[2378]-SILVER FROM LEAD.-Will any reader
and how to remedy the defect ?-J. H. C.
give some information about the extracting of silver
[2398.]-BOOK-KEEPING.-Will someone tell me
from lead, more particularly as regards the cupella- of a good treatise on book-keeping suitable for a manu-
tion, and what is the best kind of furnace? I under-facturing concern-such as an iron works?-T. W.
stand the melting of the lead, but not the cupellation [2399.]-DIE FROM MEDAL.-I have a beautifully-
of it-SILVER ORE.
worked medal. What would be the best way to make
[2379.]-CLARIONET.-Will Dr. Ussher or some
a die, or stamp the same pattern, and what is the best
other correspondent that possesses a clarionet kindly
material?-MEDAL.
give me information on the following points in au [2400.]-CLEANING BLUE TILES.-Would any of
instrument in the most useful key for use, say, with your readers kindly tell me the best way to clean blue
the pianoforte ?-1. The exact length and 'inside Staffordshire bricks from lime which has fallen upon
diameter of each joint, including the bell, of which them in white-washing? Perhaps you could suggest
latter I require the length and diameter of each end? so me method either by a cheap acid, or otherwise.
(This, of course, must not include the parts with the E. D. B.

thread round, as they, obviously, do not contribute to [2401.]-BREAKING WEIGHT OF OAK BEAM.
the length.) 2. The exact distance from the extremity-Allow me to ask Robert Pickwell the method of
of the reed to each finger hole? 3. The number of finding the strain and breaking weight of an oak or
keys necessary, and the position of all except those any other wood beam-say of the following dimen-
which are between the fiuger holes, of which I only sions: 18ft. long and 12in. square, supported at each
require the names, unless he is able and willing to end?-JOHN KYLE.
supply these also which would, perhaps, be as well?
-REED FANCIEB.

[2380]-FOUCAULT'S MERCURIAL CONTACT BREAKER FOR RHUMKORF COILS. Will someone describe the above, and also state whether or not it possesses any advantages over the vibrating contact breaker?-R. S.

[2402.]-ELECTRIC BELL AND BATTERIES.-
Will Mr. W. H. Stoue, who has lately given us a
description of the manganese battery, answer me a
few questions concerning it?
In the first place, then,
how inany cells should be required to ring a bell that
rings well with two-piut Smee cells? I have tried it
with eight Minotto's cells, and it would not ring at all.

any kind [2411.]-GRINDING LENSES.-Will reader inform me where I can buy the gauges and counter-gauges used in grinding the lenses of microscope objective ?-HIPPARCHUS.

his mangauese battery, its construction and arrangements, in our next number, for a fellow-subscriber?ELECTRO.

[2413.] - -DOMESTIC TELEGRAPH.-Will some practical reader answer query 2099, p. 661, of the last volume ?-J. O.

two numbers whose difference is 2, and product multi[2414.]-ALGEBRAIC EQUATION.-What are those plied by their sum is 12? Please work out at length.

-PATER.

[2415]-SARSAPARILLA-Could any reader inform me how I could make a decoction of sarsaparilla? I want to make it so that it shall be strong enough so as not to use more than one or two tablespoonfuls in a wineglass of water.-SARSAPARILLA.

[2416] ADHESIVE MATERIAL.-Would any reader inform me what is the best adhesive material for affixing ordinary paper labels on brown paper parcels, how it is made, what it is made of?-BETA. [2417.]-FERNS.-Will any reader inform me how to construct a fern case, medium size, and the best species of ferns to stock it with? 1 do not want costly ones. A few hints on their cultivation would be very welcome.-IGNORANT.

[2418.] OXFORD AGRICULTURAL EXHIBITION.-Can any reader inform me what class of implements will contest for the prizes at the Agricultural Society's meeting at Oxford?-GEO. HOLDON.

[2419.)-GALVANIC BATTERY.-Is it necessary to amalgamate zinc wire for a salt-water battery? If so, which is the best way to put the mercury on?→ VOLTAIC.

[420]-SPRING BOW-Can I weaken the spring of a spring-bow without making it thinner? It cannot be mode longer, boing in one piece.—VOLTAIC.

THE ROYAL DUBLIN SOCIETY has commenced its session for the delivery of popular scientific lectures. Some of last year's courses, were of the deepest interest. Mr. Huggins has already given one of the present course of lectures "On Recent Solar and Stellar Discoveries." Amongst others it is an[2426.]-UNANSWERED QUERY.-PIG IRON.-nounced that Dr. R. M'Donnell will give a lecture "On Phosphorescence and Fluorescence; Could some reader of your valuable and widely-circulated journal tell me the reason why pig iron that has Hull, "On the Coal-fields of Great Britain; Dr. to atmospheric influences, almost invariably works been stocked some six, nine, or twelve months' exposed better in every respect in the forges, and its products in the mills are more satisfactory than iron that is newly made at the blast furnaces? - AN IRON WORKER.

surfaces?-THOMAS BAXTER.

[2430.]-TO MR. GEORGE BATES.-I should be much obliged to Mr. George Bates, agent for Hopkinson's valve, if he would give me the rule by which the calculation is made as regards loading the valves, one valve being smaller than the other, and one being without a lever and likewise the float; what weight it would take to lift the small valve at a pressure of, say, 25lb. to the square inch? I should like to correspond a little more with Mr. Bates on the mechanical improvement he sees in his daily travels (through the medium of the MECHANIC), which will benefit ine and others also to insert his address. His last information corresponded exactly with my views on the compound safety valve.-A. F., Leamside.

[2431.]-WEDGWOOD PLAQUES.-Where can I procure the above, of small medallion size for enlaying, and about what would be the cost ?-F. S.

[2432.]-STONE CARVING ON SCULPTURE.Would someone of experience tell me a little about the tools and mode of procedure, and working? I can work at wood carving.-F. S.

[2433.]-KEYLESS WATCH BUTTONS. — Will some reader tell me how the gold is put on the iron or steel in the buttons of key less watches?-J. HOLT. [2434.]-MEASURING LABOURER'S WORK.— Will any brother reader inform me how to measure land, &c.-such as is required upon a farm-as I wish to be able to measure the work done by the labourer? -A YOUNG FARMER.

[2435.]-PROJECTION.-I will be obliged if Mr Quilosa or any other subscriber will give an explauation of the following problem :-A cube of lin. edge is to be represented by its plan and elevation when the planes of two faces are inclined at 50° and 70° to H. P.-T. CORNFORTH.

[2436.]-TO "F.R.A.S."-I am much obliged to our learned friend "F.R.A.S." for his courteous reply, but regret that my letter was not fully understood. I stated that I proposed grindin an object glass of 18ft. Sin. focal, and that the glass I intended using would require the crown lens to be 6ft. 10in. focal length to correct the chromatic aberration. I know for certain this will do it, so that the focal lengths are settled. But what I wish to know is, what would be the best curves to correct the spherical aberation, the outer curve of the crown, and the inner curve, also the outer and inner curve of the flint lens? I know that our learned friend could do this in a few lines. I should like to grind them according to his formula, if he will favour me with one.-NEPTUNE.

APRIL 8, 1870.]

been introduced during the past week at Portsmouth
in the trial of two large plates for the Glatton and
the Devastation breastwork monitors. Hitherto, the
practice has been to fire at the plate with spherical
shot from the smooth bore 8in. gan, but the method
now brought into use by the Admiralty substitutes
the 7in. nuzzle-loading rifle gun with chilled shot for
the smooth bore. The powder charge varies accord-
ing to the thickness of the plate under test in the
following degrees: For 12in. plates, 211b.: for 11in.
plates. 18tib.; for 10in. plates, 161b.; for 9in. plates,
14lb. The distance between the gun and the plate is
30ft, and four shots are fired at the plate within an
an area of two square feet. The plate for the Glatton
was from the rolling mills of Messrs. Charles Cammell
and Co., Cyclops Iron and Steel Works, Sheffield,
measuring 10ft in length, 3ft. 6in. in breadth, 12in. in
thickness, and weighed 7 tons and 2 cwt. The plate
for the Devastation was from the rolling mills of
Messrs. John Brown and Co., Atlas Iron and Steel
Works. Sheffield. Its dimensions were 14ft. in length
by 4ft. 6in. in width and 10in. in thickness, and weight
10 tons. The average penetration of the shots in the
12in. plate was 7.2in., and in the 10in. plate the pene-
trations were 63, 8, 68, and 7-8in. respectively. It is
a remarkable feature in the manufacture of these
enormous slabs of iron for our new turret ships that
they are bent to the required form direct from the
rolls, and when at cherry-red heat.

CANDLE STAMP.-It is marvellous, writes the Scientific Review, to observe what trifling articles may form the subject of a useful invention; the stamping of candles, for example, would appear to be a very unimportant matter, yet Mr. Schleidner, of Paris, has designed a special machine for the purpose. The candles are placed on an inclined plane, from which they successively slide into the notches of two simiJar wheels or rings, which, at each revolution of the driving pulley, bring a candle under the stamp. This stamp. suitably engraved, is heated to an unvarying temperature, by steam or otherwise, so that on pressIng lightly upon the candle it melts the fatty matter, leaving the candle stamped with a very clean impression, ontained without shock or stain. The candle then leaves the notches, falls upon another inclined plane, and passes thence into a box.

It is reported, on the authority of the late Major-
General Davis, of the Royal Artillery, that the Redu-
vius serratus, commonly known in the West Indies as
the" wheel bug," can, like the Gymnotus electricus,
communicate an electric shock to the person whose
flesh it touches.

M. HESLING states, in the Journal de Pharmacie et de
Chimie, that eveu long before milk becomes sour there
are generated in it very small organised spores of an
Ascophora species.

THE exports of railway iron from the United King-
dom attained a heavy total last year, having risen to
895,848 tons, while the corresponding total for 1867 was
only 583,488 tons.

M. Alphonse Milne-Edwards shows that at the time of the deposition of the tertiary beds of Bourbonnais its Fauna represented that now existing in Africa.

M. Hurtault has patented a process for rendering petroleum inexplosive by the addition of a certain proportion of amyl alcohol.

A process for the manufacture of artificial butter has been patented in France.

M. Oudemons has succeeded in making an alloy of zinc and iron. The new metal, which contains 40 per cent, of iron, is remarkable for its whiteness and tenacity.

DOMESTIC RECIPES.

(From the Food Journal.)

THE VOCALIST'S SOUP.-Take three ounces of sago, and,
after washing it in boiling water, add it gradually to about
two quarts of medium stock, which should be almost boiling.
After half-an-hour's simmering, it will be well dissolved.
Beat up the yolks of three eggs, add half a pint of boiling
These materials
cream, and stir them all quickly in the soup, not allowing the
latter to boil, lest the eggs should curdle.
will make sufficient soup for eight people, so that it can be
recommended for dinner before an amateur concert.

POTTED PIGEONS.-Stew the gizzards and livers of the
pigeons, chopped fine, and add grated ham, bread crumbs,
This is to be made into a force-meat, with the
and herbs.
yolk of a hard-boiled egg, and the pigeons are to he stuffed
Put them into a stewpan, with water and a little
with it.
butter; add the gravy from the gizzards, some four, and an
onion, with the addition of a glass of wine, and stew gently
until done.

VEAL SOUP.-Boil the real with two-thirds of a cup of
rice, and add sweet herbs or celery, and the usual seasoning.
This makes a plain, wholesome soup.

NEW METHOD OF EXTRACTING GELATINE, &c.-It is announced that a mode of obtaining gelatine from all animal substances capable of yielding glue has been discovered. The oils and grease are separated from the gelatine by means of benzine, coal-oil, or other hydrocarbons. In some cases it is found advantageous to treat the material with lime, before the hydrocarbons are employed; but these are exceptional. After the substances treated have lain for a considerable time in benzine, or other agent employed, the latty matters are dissolved, and the pure gelatine is found at the bottom of the vessel; they are, therefore, easily THE PRESERVATION OF MILK.-The following recipe separated in order to be treated in the usual manner. appeared in Cosmos-"To every litre (= 1 pints, 5 oz.) of The hydrocarbons are recovered by evaporation, by unskimmed milk, previously poured into a well-annealed means of steam and condensation, and both the gela-ginss bottle, add 40 centigrammes (about 6 grains) of bicarine and the fatty matters are afterwards purified by bonate of soda. Place the bottle (which must be well corked) he ordinary processes, containing the milk for about four hours in a water-bath, heated to 900 (194° Fabr.). On being taken out, the bottle is varnished over with tar; and in that state the milk contained in it will keep sound and sweet for several weeks."

THE WATER TYPE.-Mr. Wanklyn has recently published an important paper that will probably give rise to much controversy. It does not admit of brief abstraction. The author desies the analogy between the acids and metallic salts; that the acids are built on the water type he is indeed not prepared to deny, but be maintains that the acids and the metallic salts are built on totally different types. The alkalies, instead of being waters, and iike the acids in structure, are like metallic salts. Thus caustic soda is Na

H!

POTATOES A LA MAITRE D'HOTEL.- Peel the potatoes, when boiled, and, after trimming them into the shape of large corks, cut them into slices in thick; then place them in a stewpan, with sliced green onions and minced parsley, pepper, salt, and butter. Moisten them with stock, and let them be well tossed, until the parsley is cooked.

ANSWERS TO CORRESPONDENTS.

ANOTHER TESTIMONY.

SIR,-I have great pleasure in adding my testimony to that of the other subscribers, as to our MECHANIC being a first class advertising medium; in fact, I have found it so good that I have been obliged to very much increase my facilities for the execution of orders. I may also say, I am much appear outside, and the general improvement of the paper.pleased with the new arrangement for advertisements to F. PERKS, Wolverhampton.

RECEIVED.-J. G., S. & R., S. S. & Co., James Hunt, W. H.N.
J. G. Watts, W. Melroy, J. E. Pearson, G. Woods, J. Hinks
& Son, T. Winter, B. & Co., Fred. Walton, W. Butler, H. H.
Lloyd, Otley & Nuder, W. H. C., W. Ferrell & Son, W. A.
Gibbons, J. E. Holmes, T. J. O'C., Geo. Jackson, C. & H.,
George Plant, W. M. W., R. W. P., W & T. Pye, Excelsior,
J. K. P., F. J. H., J. Kilburn, W. E. Hickling, J. Radcliffe,
John Holmes, Procul, M. A. Ennis, W. J. C., R. Rumsey,
S. W. & Co., J. C. Scott, W. C. R., Capt. O. Haldaue
Stokes, R. A. Proctor, Omicron, J. Rattray, Coalbrookdale
Co., H. Bradley, C. C., E. S., C. B. A., B. N., J. V, S. S. &
Co., J. Rattray, S. & J. F. D., J. W., M. B. A., S. W. & Co.,
P. Bros., E. S., J. Holt, W. C., J. Kilburn, J. Radcliff, W.
P., P. Champs, R. J. Boyall, W. H. Coffin, Caffal and
Miller, E. V. S., F. H. B., Hy. Canning, C. S., J. Jennings,
C. and D. Jones, C. H. B. H., W. Leary, A. Tolhausen, J.
E. Fenney, Edwardian A., Geo. Gregory, A. F. S., W. H. B..
Neptune, G. E. Crick, One in a Fix, A Young Farmer,
Ianthe, S, M. J., J. Holt, J. Cornforth, Delineator, H.
B. A., G. G. Ventnor, Waherof, Thos. Stanway, J. O. Clark,
An Old Sub.. A Young Irishman, W. H. Ridgway, Ash-
hurst Bros., W. R. Bland, H. C.

WILFRED.-Your query, like too many which reach us, is very
ambiguously worded. You do not say what Leather your
couch is covered with, therefore no one could advise you
how to clean it.

HYPO.-We never pass any correspondent unnoticed.
SIGISMOND.-State more precisely what instrument you
require music for.
CHUCK.-Consult indexes.

J. D. M.-Could only say after perusal.

PESKEY CUSS.-Replies dealing with such a malady uppeared some time back. Why adopt such a signature? H.G. HOULT.-Communications on mesmerism reached us in such numbers that a general acknowledgment only was made of their receipt.

E. G. WILLINGLY.-Send us the addresses. Our simile was
founded on the Biblical account of the fate of the magicians'
rods, whose owners attempted to compete with Aaron in
miracle-working.

W. J. B.-You write anonymously, and, therefore, to no pur-
SAMUEL FORRESTER.-Only at certain times, which vary in

A

pose.

different districts.

pages.

our columns are open to you. If you want to push it com-
CHEMICAL MAN.-If you choose to describe your invention
mercially, we can only help you through our advertisement
PHONOGRAPHY.--Shorthand-writers are divided in opinion to
a certain extent as to the merits of the systems you name,
but the great majority prefer Pitman's.
GEORGE WHITAKER.-We know no other address.
LUX. We think not.

METRONOME-Second query inserted. Reply 2091 will
help you to solve the first.
SAMUEL WYMER.-We cannot advise you.
GILBERT.-You send a query to which replies are even now
appearing. Be more considerate.
AMICUS SCIENTIE-The information you ask for has been
given repeatedly. It is not our fault that you do not possess
the back numbers.

T

BANNELL.-First query inserted. A search at the Patent
Office will give you the desired information.

It may be briefly stated that the accuracy of the mode of representation proposed by this distinguished chemist entirely depends on the question, is there, as a matter of fact, a fundamental analogy, or fundamental want of analogy, between hydrogen and the The copper is then to be booked on a pot hanger, and the J. W. BEDFORD.-The correction did appear in this column.! metals? In Mr. Wanklyn's opinion, in favour of which he gives strong reasons, there is a fundamental dissimilarity between hydrogen and the metals.

DETECTION OF ARSENIC IN FUSCHINE.Dr. Riecker finds that the pigment Fuschine contains arsenious acid, the amount in some samples Leing 2:07 per cent.; he therefore recommends that there should be legal prohibition to the employment of this pigment as a colouring for sweetmeats.

CONVERSION OF CRYSTALLINE SULPHUR INTO THE AMORPHOUS MODIFICATIONM. Lallemand finds that the direct action of sunlight converts crystalline sulphur into sulphur insoluble in ulphide of carbon. By placing a solution of sulphur in sunlight concentrated by a lens, the author states that the sulphur is rendered insoluble and deposited in the amorphous form.

CHIPS.

M. SOMMER propounds a new theory of sleep: his idea is that sleep is simply a result of the deoxygenation of the system, and he believes that sleepiness comes on as soon as the oxygen stored in the blood is exhausted.

HARE A LA ST. HUBERT.-Persons who object to "high"
game will find the following recipe most useful:-The dish
is called Hare a la St. Hubert. The hare must first be
skinned soon after death, put into a copper, and great care
taken to save as much blood as possible; secondly, 4oz. of
bacon fat are to be added, with leeks, parsley, &c.; and,
lastly, a pint and a half of good strong, spirituous red wine.
wine set on fire. While this is flaming, roll six ounces of
butter in some flour, and when the wine ceases to burn, add
the butter rolls to the stew, which may be allowed to remain
on the fire for half-an-hour. A veteran French spinster,
whose word on such matters is law, bids us, on eating the
dish, bless the memory of the propitious saint. A hare, thus J. CHERRY-Please send the note on starch.
cooked, merits this effusion of gratitude.

Truss it neatly,"

HOW TO COOK TOUGH POULTRY.-Madame Miau is, what
may be called an Anglo-French authority on culinary opera-
tions. At least she was born in England, educated in France,
came back to England, studied, talked, cooked, and ate a
great deal in both countries. A friend in extremity once
asked her, what she could do with "a miserable half-starved
chicken that the dogs had killed?" Her answer was prompt
and encouraging to those mistrustful people, who are com-
pelled to dine in doubtful eating houses.
Madame Miau replied, "stuff it with sausage and bread-
crumbs; mix some flour and butter, taking due care it does
not colour in the pan, for it must be a white rout; plump
your chicken in this, and add a little water, or soup if you
have it." We are told besides to put carrots cut in half, tops
of celery, chives, bay leaf, parsley, &c., then "cover close, 80
that all air may be excluded, and keep it simmering two
hours and quarter; it will turn out white and plump place
the vegetables round it, stir in an egg to thicken the sauce,
off the fire, and your dish will make you blush." Without
actually snatching hall-starved chickens from the mouths of
dogs, might not Madame Miau's instruction render many a

Cosmos" asserts that it has recently been demon-tough old bird palatable? strated by reference to authentic documents that Guernsey and Jersey have sunk more than fifteen yards during the last five centuries.

On Saturday the 26th ult., Mr. Green, the celebrated aeronaut, died suddenly at his residence, Tuffuel. L'ark, in the 84th year of his age.

DR. HOOKER has been elected an honorary member of the French Acclimatisation Society, on account of lis exertions in regard to the Cinchona plant.

THERE are in America and Europe more than 250 manufactories of rubber articles, employing some 500 operatives ench, and consuming more than 20,000,000lb. I gum per year.

THE ENGLISH MECHANIC LIFE-BOAT
FUND

Subscriptions to be forwarded to the EDITOR, at 31, Tavis-
tock-street, Covent-garden, W.C
Amount previously acknowledged
164 6 1
010
J. S.
0
0 1
Vibrator
0 5 0
R. G. B.
W. H. Coffin
0 3

33

164 13 4

A BROTHER can only have his query inserted as an advertise-
ment.
NOVICE thanks Mr. A. W. Blacklock for answering his ques-
tion on parabolising specula. With the assistance of the
diagram "Novice" says he "saw the thing at once."
F.R.G.S.-Thanks for your offer to "supply epitomised
accounts of the proceedings of the Royal Geographical
Society." We are sorry, however, we cannot give you
much space.
Whilst bestowing
DR. B.-As you say, nothing is perfect.
We cannot
praise on most things you ridicule others.
reply to all, but will refer to one as an example-that of
"Pills." You have no patience with "Wry Face" for
asking such a question, and you are not the only one who
has so written. On the other hand, we beg to say that the
question was asked by one of our most intelligent corre-
spondents; that it was a fit question to ask, and that it
has elicited several valuable suggestions, one of which
A question like this, or the answers it
appears to-day.
elicits, may not be interesting to "Dr. B" and others,
but they are interesting because useful to many others.
J. MILLS-See letter "Criminal Literature" on another
page. One letter on the disagreable matter is enough.
DR. B.-We cannot advise as to the quality of the goods men-
tioned in advertise ents. The house you mention, that of
Mr. Cox, Ludgate-hill, London, is a respectable one.
DR. USSHER-In printing a large number of copies, and
rapidly, some badly-printed sheets occasionally pass through
the machine, and we suppose your copy last week was an
unfortunate оне.

CANUTE.-You give good reason for using "Terset Deuroy,"
the name of your residence. "Canute" rolls over the tongue
a little more easily. Certainly "Neptune cannot object

A FRIEND TO IMPROVEMENTS.-There is no person or society to give a reward for such an invention; but if it be as you say, any capitalist would co-operate with you, or if you gave the invention to the nation, the Government might give some kind of reward. Sir Wm. Armstrong, for instance, was rewarded vastly and made a baronet in the bargain, when he offered his invention to the Government, but the invention was worthless, nevertheless. But Sir William was an adroit and persevering diplomatist. His gun has cost the country at least £3,000,000, and we shall never get in return 3,000,000 farthings.

ARGUS. The suggestion, if made, would not, in all probability, be adopted.

SCRUTATOR.The matter in dispute between you and Minnehaha," would hardly justify the insertion of more letters on it.

WM. TURNER.-Questions publicly asked, must be publicly

answered.

EQUATION.-No. 2258. Several answers have been received. We give preference in such matters to the shortest. HERALDRY.-W. H. H. says:-"If Lincolniensis' has not yet purchased a work upon heraldry, and if, further, money is any particular object to him, I shall be happy to send him free gratis" an old, but, I believe, perfectly reliable book, containing, besides the treatise, the arms of the nobility of England, Scotland, and Ireland.' If he would like to have it, and will send his address to me at 12, Chapel-street, Bedford-row, W.C., I will despatch it by next book-post."

THE SIXPENNY SALE COLUMN is the only place in which can appear queries forwarded by E. Spencer (second query), "Vulcanite," J. Benson, "W. G. H.," "Tyne," "Metal

Head," "Tackle Maker."

JOHN C. SCOTT.-Not received.

W. R. BLAND. We intend to give chess problems, but yours
is incorrectly stated, and is not a very good one. In the
first place the W. R. moves to the Q. B. 4th, and not to the
Q. B. 5th square; next the White Queen moves to Q. 5th,
and checkmates, and not as you say, to Q. 4th.
J. W. T.-If the drawing and description were given they
would be of no use to anyone but yourself.
W. S. MCKAY.-Ingenious but impracticable.

865 J. Sawyer. Alma-street. New North-road, London, N., and J. Brindley, Sunnyside-house, Chingford, improvements in furnaces 866 S. Bateman, Asnieres, apparatus for measuring card filleting whilst making

867 G. A. Buchholz, Regent's-park, machinery for manufacturing semolina

868 E. Cambridge, Bristol, improvements applicable to steam boilers or generators

869 T Claridge, Bilston, and J. Jeavons, Sheffield, armour plates 870 W. R. Lake, improvements in turbine water-wheels-A communication

871 L. Watson and J. Hall, Craven-street, Strand, registering

goods raised or lowered in breweries, and other buildings

872 W R. Lake, preparation of ammoniated sulphuric acid-A communication

873 A. Baumann. Heilbronn, steam engines

874 T. Gibb, and C. Gelstharp, Jarrow-on-Tyne, smelting copper and other metals.

875 T. Gibb and C. Geltsharp, Jarrow-on-Tyne; extracting copper from ores

876 T. J. Smith, of Robertson, Brooman, and Co., 166, Fleet-
street, new docimastic process for treatment of simple and complex
sulphurets and the arsenic sulphurets of lead, antimony. copper,
and iron, as well as coppery matts and coppers containing precious
metals, to extract silver and gold therefrom.-A communication.
877 W. R. Thomson, Glasgow, improvements in locks, latches, or
bolts

878 E. T. Truman, Old Burlington-street, improvements in treat-
ing and preparing gutta-percha
879 R. F. M. Harcourt, 9, Essex-street, Forest gate, Essex, im-
provements in fastening railway carriage doors

880 J. Cross, Bristol, propelling vessels

881 J. Townsend. Glasgow, obtaining and applying iron and
manganese protoxides in utilising bye or waste products in the
manufacture of chlorine, copper, and alum

882. B. IIunt, 1, Serle-street, Lincoln's-inn, valves.-A communi-
cation.
883. A. Dixon, Railway-place, Fenchurch-street, railway or other
season tickets

884 C. Jean, Paris, weighing cart

885 W. R. Lake, improvements in valves.—A communication
886 W. Ramsden, J. C, Pearce, and B. Ayrey, Bradford, apparatus
for sorting wool

887 A. Angell, Rio de Janeiro, heating and delivering metal bars,
-A communication

888 W. H. Grassam, Spalding, improvements in horseshoes
889 C. D. Abel, 20, Southampton-buildings, machinery for grinding
and polishing saws.-A communication

890 J. C. and G. Watson, Leeds, machinery for making dip candles
891 T. J. Smith, Robertson, Brooman, and Co., apparatus for

892 A. Dickinson. Hartshill. Stoke-upon-Trent, W. W. De la

Rne, Bunhill-row, bezique markers

LOTTERIES-GREAT PRIZES, &c.-J. T. Keighley, of 20,
Barton-street, Ribbleston-lane, Preston, writes to complain
of the non-receipt of a prize drawn by him in a distribution
which took place some time back in connection with
another journal. He and any others who have similar
complaints to make had better apply to the former pub-regulating driving of millstones.-A communication.
lisher. We have had nothing to do with "prize distribu-
tions," and never will. There is really nothing given to
the subscribers. When these distributions are honestly
conducted, (which we fear is but seldom the case), each
subscriber has to forward four or six stamps, which more
than defray the cost of a considerable number of "magnifi-
cent prizes," which generally consist of bull's-eye lanterns,
concertinas, and similar valuable articles.
KENNINGTON AMATEUR.-Inquire through a bookseller.
W. ROBERTS.-No.

J. W. RUSSELL-We are afraid you are hard to please. Such
letters only discourage.

FREDERICK SMITHE-Agreed.

E. KERNAN.-With MSS., making four packets in all.
F. D. HABT.-Mispickel is arsenical pyrites.

B. JOHNSON." Hungary" is thus made on a large scale. 10
gallons of rectified alcohol, 60% over proof, 15 oz. of otto of
neroli of lemon, 5 oz. otto petit grain of orange, 6 oz. otto
of rosemary, 8 oz. etto of citron zesle, 2 oz. of otto neroli of
orange.

M. VAN B.-Probably rutile (native oxide of titanium,
coloured by iron). It has sometimes been met with in
specular iron,

B. L.-Vanadium was discovered by Sefström in 1830, in a
Swedish iron mine at Jaberg.

THE INVENTOR.

IN obedience to the suggestions of a number of readers, we have decided on appropriating a portion of our space to a condensed list of patents as nearly as possible up to the date of our issue.

APPLICATIONS FOR LETTERS PATENT DURING THE
WEEK ENDING MARCH 29th, 1870.

840 J. Milne, St. Andrew's, fire grates
841 R. H. Rimes, Bradford, boots and shoes

E 842 W. H. Clemesha, and T. Roberts, filters

843 W. Gallimore, Leek, machinery for drying thread in the hank 844 D. Joy, Saltburn, increasing efficiency of steam generators 845 W. R. Lake, counteracting pressure on slide valve engines,A communication

846 8. S. Turner, Westborough, Massachusetts, machines for sewing straw

847 J. H. Johnson, 47, Lincoln's-inn-fields, improvements in locomotion-A communication

848 D. Gray, Wishaw, wheel tyres

849 T. J. Smith, of Robertson, Brooman, and Co., 166, Flootstreet, treatment of ores.-A communication

850 C. J. Eyre, Westbourne-grove, apparatus for producing motive power

851 J. and J. Bradbury, Denton, machinery for felting hat

bodies

853 J. B. Colbran, and W. Pollard, Holloway, trap for vermin or animal

854 C. Farrow and R. B, Jackson, Great Tower-street, iron wine bins

855 M. Chapman, Charterhouse-buildings, Goswell-road, improved album

856 W. R. Lake, Southampton-buildings, bars, plates, and sheets of steel.-A communication

857 J. Moore, Dublin, metal bushes for bang holes of casks 858 J. C Cushion, Penrose-street, Walworth, improvements in mill bills or chisels

859 J. H. Miles, Birmingham, velocipedes

860 S. Mawson, Bradford, nitrous oxide gas (or other gas that may be inhaled) indicating the quantity at each and every inhalation 861 T. P. Hawksley, New Bond-street, clinical thermometers 862 J. Gilchrist, Glasgow, ratchet drill, brace, and grab combined

863 H. R. Fanshawe, 14, Finsbury-place, and W. H. Smith, 12, St. Ann's-gardens, Haverstock-hill, treatment of hides and skins in tanning

864 R. H. Kay, and A, T. Richardson, Mobberley, improvements in manufacture of crape.

893 J. C. Morgan, H. Macaulay, and F. W. Waide, Rotherham,
register stoves.

894 W. Dobson, Stockton-on-Tees, apparatus for cooling liquids
895 W. Bailey, Wolverhampton, brewing

896 J H. Johnson, extracting moisture from peat, clay, and other
materials

807 A. M. Clark, 53. Chancery-lane, rotary printing machines
898 J. W. Perkins, Herne-hill-road, fuminating compound

899 R. Smith, Manchester, doubling and winding yarns and
threads

900 J. Hopkinson, Lower Town, near Keighley, and R. Newton, Engineer, spinning and twisting fibrous substances

901 J. Sampson, and R. R. Minton, Liverpool, improved varnish
paint

902 W. Gray, and T. Biggin, Sheffield, metal bushes for casks or
barrels
903 S. P. Baker, Whitton, near Hounslow, locking and unlocking
gates on railways
904 J. H. Johnson, 47, Lincoln's-inn-fields, wrenches-A comma.
nication

905 A. Nicole, Soho-square, improvements in lever escapements
906 W. R. Lake, improvements in anchors.-A communication
907 W. E. Newton, 66, Chancery-lane, improvements in pumps,-
A communication

908. J. S. Davies, and W. E, Yates, Manchester, looms.
909 O. H. Weed, Boston, U.S.A., cabined washing machine
and ironing table,

PATENTS BEING PROCEEDED WITH

3297 G. R. Mather, giving form to wood
3306 J. Garrard, buffers

3307 W. Niell, Lancaster, Engineer, blast engines
3312 S. J. Mackie propulsion of vessels
3324 C. Faure, galvanic batteries

8328 H. A. Hammond, improved chimney cowl
3629 G. Petrie, brick and tiles and manare

3334 T. E. Lundy, and J. L. Dunham, improved means of commu-
nication between passengers

3340 W. and M. Bayliss, cast-iron earth screws

3943 W. J. and F. W. Edmondson, engraving cylinders used in printing

3346 H. Wilson. lubricating apparatus

3347 B. Giuseppe, boilers

3353 T. R Hetherington, machinery for preparing, spinning and doubling cotton

3354 D. Morgan, lubricating oil or grease

3355 T. F Lynch, bottles for holding poisons

3358 W. R. Lake, distributing type

3360 S. L. Loomis, apparatus for tightening and holding window sashes

3364 R. Wilson, hydraulic presses

8367 J. Bourne, improvements in gauges

3373 J. Thomlinson, cements

3376 H. A. Bonneville steam-boller supply cock

3377 H. A. Bonneville, Improvements in electro-metallurgy
3378 H. A. Bonneville, elec ric batteries

3380 J. E. Croce-S pinelli, propelling and steering vessels
3381 E. Round, indica or for marking games.

339 W E. Gedge, improved system of hydraulic traction
3397 J. Turnbull, connecting and disconnecting carriages and

3570 W. E. Gedge, velocipedes

3645 A. M. Clark, manufacture of superphosphate of lime 219 F. Kohn, extracting juices from plants

553 H. Bessemer, lessening or preventing sea-sickness

569 J. Saxby and J. S. Farmer, locking or securing railway points and signals

594 C. W. Siemens, treating iron ores

658 E. Stevens, apparatus used in cooking

696 J. Neilson, hollow cast-iron cooking utensils
711 J. Jeavons, armour plates

725 H. A. Bonneville, machines for setting types
736 J. Polson, treating grain

775 G. Holdsworth, preparing designs on ruled design paper for manufacturing purposes

780 J. T. Walker, horseshoes

782 W. R. Lake, forming trenches or ditches

819 G. W. Fox, treatment of medicinal oils, to render the same palatable

All pen ons having an interest in opposing any one of such application are at liberty to leave particulars in writing of their objections to such application at the office of the Commissioners before the 9h of April, 1870.

PATENTS SEALED.

2612 J. Porteous and H. Gibson, manufacture of tobacco
2805 R. Harlow, improvements in valves

2810 T. R. and T. W. Harding, leather driving bands
2815 J. Taylor, bradawls

2816 W. Whiteley, apparatus for roving and spinning fibrous substances

2823 H. Y. D. Scott, improvements in kilns

2835 H. Hughes, reducing metal rods, bars, or tubes

2937 J. Anderson, improvements in treating maize

2839 H. Woolf, hat brims

2846 J. Dewe, construction of locks and indicating number of times lock has been opened

2849 F. S. Barff, utilising vapours arising from furnaces

2872 F. Grau, improvements in lamp sockets

2880 C. Montagu, improvement in umbrellas

2932 A. Brooman, liquid meters

2938 B. Baugh and B. Walters, ornamenting bricks

2964 W. Bennett and J. Carrall, improvements in kitchen ranges 3040 A. V. Newton, a sacking for bedsteads

3131 W. E. Newton, improvements in drawing frames 2856 A. J. Eli and H. Sawahn, apparatus for registering distances travelled by vehicles

2864 C. A. Maugin, silvering looking-glassos

2889 T. W. Bunning, and W. Cochrane, apparatna used in getting minerals

2949 A. Welch, cattle trucks

2257 W. R. Lake, permanent way of railways

2973 J. Smith, timing ships' logs

3005 W. R. Lake, improvements in sewing machines
3038 C. E. Spagnoletti, apparatus for signalling
3039 A. Welch, cattle trucks

3095 J. H. Johnson, adhesive compound for stamps
3162 B. Bianchi, cartridges

3211 A. M. Clark, boring tools

3383 H. F. Shaw, cutters for mowing machines

3497 J. Smith and T. Eastwood, working and reversing valves of engines

3544 J. S. Robertson, improvements in horse-shoes for frosty weather 3680 F. Ellershawsen, and T. Wehle, apparatus for utilising the force of the waves

22 C. Wyndham, apparatus connected with bicycles

64 B. Brown, improvement in machinery for spinning fibrous

substances

901 J. Werndl, fire arms

911 D. Foster and R. Cooke, casting of Bessemer steel hoops for the tyres of railway wheels

859 G. Davies, rotary digging machines

861 J. Johnson, textile materials

863 A. Wyley, breech-loading fire-arms, and bayonets

874 E. O. Greening, iron and continuous fencing

886 G. E. Donisthorpe, getting coal and other minerals

907 W. Crighton, preparation of fibrous materials

922 E. H. Aydon and E. Field, smelting iron and other ores

927 W. Easterbrook, railway points and signals

939 W. Bywater, drawing, spinning, twisting, and laying of hemp, fax, &c

1034 W. P. Butchart, treating and softening jute, hemp, flax, and other fibrous substances

917 G. A. Buchholz, manufacturing semolina

918 J. Howard and E. T. Bousfield, machinery for cutting and spreading grasses

1004 J. H. Barker, improvements in milling machines
1064 J. H. Player, phosphorus

891 E. W. Shirt, plane irons

PATENTS ON WHICH THE STAMP DUTY OF £100 HAS
BEEN PAID.

770 G. Davies, improvements in wrappers or papers for needles
769 J. Reilly, lubricating shafting and bearings
779 J. H. Worrall, producing surfaces in imitation of wood
942 J. Smith, furnaces and boilers