This machine is commonly called a "milling machine;" there are also the "fulling stocks" which are used for the same purpose, but the milling machine is considered the best. A is a flanged roller about 6in. wide, into which A runs geared by the two wheels B and B. The piece is passed through the knocking-off board F, which is connected to the driving pulleys by means of levers (not marked in the sketch), so that if the piece should fasten itself, as is very often the case, the board is lifted up and the machine stops. E is a plain roller over which the cloth passes to the flanged rollers A and A on its way to the spout C, where the most of the milling is done. D is the top to the spout, which is weighted according to the requirements of the cloth. H H are the wood coverings to the machine. G G represent the piece in its passage through the machine. This machine, I believe, is the best out, it being capable of milling almost all classes of goods. Any further information I shall be glad to furnish if required.-ARDASIER. [6750.]-TO ENGINEERS.-Is there not some mistake? Six slide valves to one cylinder! and what is the "cut off?"-JACK OF ALL TRADES. [6752.]-SOAP FROM MINERAL OIL.-By adding tallow and rosiu you may do it ; not otherwise.-JACK OF ALL TRADES. [6754.]-PERFORATION OF POSTAGE STAMPS.The machine for this purpose is a patent affair, which the Post Office authorities bad to pay for pretty smartly. Potato starch is the foundation of the cheap British gum."-H. O. B. [6756.]-CHUCKS FOR LATHE.-A "Self-taught Mechanic" will find the following a good plan for boring his cylinder :-Face the ends in the centres, which [6764.]-CASTING FROM PLASTER MOULDS. The best thing "Anon "could do would be to take the castings in clay, as it is the simplest method, and much less trouble.-L. R. C. [6771.]-ORIGINAL GRAVITIES.-To fully describe the customs and method of ascertaining the original gravities of beers, with the necessary tables, would occupy more space than our editor would like to allow, as the subject is not of general interest. I therefore refer Aroma" to Bolley and Paul's "Manual of Technical Analysis," published by Bohn. See pages 336 to 841. If there is then anything "Aroma" wants cleared up I shall be happy to do it.-W. L. [6776.]-MARBLE CEMENT,-I would advise "R. G." to sift some plaster of Paris through muslin and mix it with shellac dissolved in spirits of wine or naphtha, and apply to the parts to be joined immediately after mixing, and squeeze out as much of the composition as possible, wiping the surplus off before it sets. But previously to the pieces being joined if they have not been roughed, get some steel tool with a sharp point and pick it slightly, so as to cause a kind; of undercutting, which OF ALL TRADES. enables the cement to hold much better.-YOUNG JACK [6789.]-SMALL-POX.-Chloride of lime, as a di fectant, although decidedly better than nothing, is much inferior to carbolic acid as a destroyer of germs which communicate the disease from one p to another. In order to obtain the fall protecti derived from the use of carbolic acid as a disinfe it is absolutely necessary that it should be used intermission. The air of the room in which the p lies, the furniture, also the clothes of the attes ought to be constantly impregnated with carboli This may be best secured by means of a small gas s the acid being placed in a saucer which floats in a of water, kept heated by the stove; or a more h method consists of pouring about two tablespom of the acid upon a hot shovel, and carrying the sho about the room until the room is thoroughly permes This should at least be done with the vapour. half hour; no person or article should leave the unless previously disinfected by the above me clothing, &c., being dipped into a solution of the strength a tablespoonful of acid to one gallon of water. This course of disinfection should be contine until the patient is free from every scab, when he say then be allowed to leave the room.-J. H. H (6790.]-GALVANIZING WROUGHT IRON SAL THIMBLES.-One part of muriatic acid and torben a of water put in thimbles; stir about now and then till [6783.]-BOOKBINDING.-"Amateur Bookbinder" they are perfectly clean; dry them (but do not should first screw the book up well in the cutting-press; zinc. I generally put things of this descriptions them) with a slow heat, before putting in the malta then scrape it perfectly smooth with a circular piece of wire; a dozen or so at once, to facilitate. Palais steel. He should then burnish it with a dog's tooth or murit of ammonia on the zine for a flux, dropians agate burnisher; then holding the brush in the right thimbles through nux, but when bringing out skim bats hand and a bar of iron in the left, dip the brush in the off, bringing thimbles through clear metal. This process requisite solution and then beat it on the bar of iron will do for nearly any ordinary ironwork.-J. 9. P. till the colour is nearly out, and then just touch over the edges of the book lightly with it. The usual com- [6793.]-GARDEN WALK.-Pour boiling water spes positions used for sprinkling are a solution of umber, them; gas liquor will do, but is not very pleasant to [6776.]-MARBLE CEMENT.-The best cement that "R. fresh plaster "G" could make would be to mix some fit quickly. he can do by fitting a piece of square iron in each end, and centering it true. Then clamp it against his large face-plate, with two bolts. The small American chucks-L. R. C. are the best for wire. He can get them at Mr. R. Lloyd's, Steelhouse-lane, Birmingham. He does not say what width his discs are; as they have a hole in them, I should think he might turn them on a mandril. The four-jawed chuck is the best for general purposes, and will hold four, six or eight sided nuts. He will hold his drill better by putting a centre hole in the end, and forcing it in with his centre, and having a holder in his slide rest, to keep it from turning round (it should be a flat drill). I cannot answer the question as to revol ving cutters, size of pulleys, &c., unless he enters more into particulars. Perhaps he runs lathe too fast to keep an edge on his tool. He will find 20ft. to 25ft. a minute a good speed, and must keep under the skin or scale of the iron, which is very hard. The following he will find good roughing tools. Isenu vermilion, sap-green, or indigo.-L. R. C. and a little Venetian Ped, mis it with water and a little paste, then put a few drops of common oil into it; stir all well up; dip your brush in (the larger the better), then strike it gently on the press pin until the spots are [6783.]-BOOKBINDING.-Get some brown umber the nasal organ.-JACK OF ALL TRADES. of in the [6793.]-PRESSURE OF STEAM GAUGE.-"Anxious before I can assist him; for no one could give la Now slightest information from the drawing af pay him all if he will let me know the following, I will girs him p. ormation he may need. First, the diameter of ves. Secondly, the length of the lever, and its ; and if tempered, the breadth at the extreme Thirdly, the distance from the fulcrum to the assing through the centre of the weight susi on the arm, and the distance from the fulcrum ine passing through the centre of the valve. And the weight of the valve. If the lever is balanced h I think it must, seeing a weight of 221b. to the his drawing-the statical weight may then bo ted, because a lever so constructed exerts no presa the valve.-THOMAS J. O'CONNOR. 4.1-SHARPENING FILES.-I no longer recollect whence I copied the following recipe, nor do I whether the plan recommended is found to r:-"Immerse the file in a mixture of one part acid, three parts oil of vitriol, and seven parts The time it must be allowed to remain in this -ath depends upon the quality of the metal. A very eel will require a longer immersion than a softd metal." Any one would imagine that the acid, y equally on all parts, would simply dissolve away of the metal, and leave the file as smooth and uses before. But such, we are assured, is not the Files may be renovated over and over again, and Iways as good as ever. After immersion in this Tinse the tool well in water, and then (to insure erfect removal of this acid), in milk of lime. It is wards to be dried and the lime brushed away. C. 96.]-MOLESKIN.-"The skin of the mole is used ir purposes; and made into various articles. The mole has a soft, black, shining coat; but › are varieties met with in which the fur is entirely yellowish, ash-coloured or marbled with white black spots." (Catalogue of the Collections of ial Products, South Kensington Museum.)-N. 97.1-MICRO-POLARISCOPE AND DIATOMS.polarising angle of glass is 58 (by reflexion) not 37° ven by "C. R. H." This will probably account for ailure of "C. R. H." to accomplish any good results. again. Diatoms may be found in any pond or ditch. are often to be seen as a yellowish, brownish or nish scum on the surface of the water. Oftener, aps, as a similarly coloured stratum on the bottom he ditch. Weeds, too, growing in water, have st invariably a number attached to them.-H. P. H. 798.]-WHITWORTH LATHE-See "J. K. P.'s" r. 804.1-THE TEA KETTLE.-I venture the follow-The explosion of small bubbles of steam or perhaps r collapse as they rise off the bottom causes the sic, as the little explosions in a gas burner cause flame to sing. Hot water, I think, does not sing in poured into a vessel. The vessel (only earthene I find) is the musician. I attribute the sound to › particles of earthenware knocking against each er as they get heated by the water and cooled by ir neighbours alternately. I never notice any bubbles the water, but it seems tremulous.-M. P. mixture in the porous cells will require to be removed; and how to remove the white crust which has formed on any porous cells? The battery has been set up about five months, and is charged with salammoniac. The crust is insoluble in water.-TRANSMITTER. [6831.]-THE SIPHON.-Can any of your readers give me any information (per the MECHANIC) on the following questions, viz.: What town or village is supplied with water through a siphon; state where, and also the greatest height of the tube from the water supplying the same ?-SIPHON. [6882.]-EXPRESS ENGINES.-On page 571, reply 6253,"Saul Rymea gives the dimensions of the new express engines on the Great Northern line. Will he inform me what are the diameters of the bogie, trailing, and tender wheels; the diameter and length of boiler; diameter of blast pipe; the average consumption of coal per mile, with ten carriages? and if this engine, with such a large driving wheel, is not slow in getting the train into swing on starting from a station compared with the other express engines on the Great Northern line, which have a 7ft. wheel and 17in. cylinders? Also if this engine can maintain itself well with steam when running with 26 carriages as its train ? C. E. S. [6883.]-MEDICAL COIL.-" Signas" kindly gave a description of the manganese cell, but did not say if the sizes given (84 by 3) were adapted to work a medical coil. If he will give the necessary sizes for working a coil, he will bestow a great favour on-F. S. [6884.] RECOVERING SILVER.- After precipitating, swill with old battery acid. I have a mixture of sulphate of copper, potash, and silver; will any one tell me how to recover the silver pure from this mixture ?ELECTROPLATER. [6885.]-THE LEVER.-Will some of your able correspondents kindly say if there is any rule to find the following:-1st. How can I find what length a lever must be, say to lift five hundredweight, the weight being 6in. from tulerum or pivot, the power being one hundredweight, or, in other words, I hang 5lb. on one, and 1lb. on other, the centre being 6iu. from 51b.; how long must lever be to balance, and the rule to find the same? 2nd. Respecting blocks and falls for lifting. If I hang up one sheave I suppose one pound would balance one pound, but if I put two sheaves at top and one at bottom, how much would one pound be able to balance? What I really want is, suppose I want to lift half ton, and I have a three sheave block at top and a two sheave at bottom, what weight in man power shall I require to lift the half ton ?-J. S. F. [6886.]-RUST IN KITCHEN BOILER.-I have a rust in the water. Could any one inform me what would kitchen boiler which accumulates a great quantity of remedy it ?-Jos. NORBURY. [6887.] RIMS OF WHEELS.-Will some reader inform me how rims of wheels are put on; in two pieces or in one piece? I find great difficulty in putting a felloe on a wheel, say, 4ft. 6in. high, with 8in. stock, 24in. rim. I find that the holes are about 4in. to 4in. shorter on 6810.]—CUTTING ENGINE.-" A Country Clockthe inside than on the out, so that when the felloe is ker," in order to cut wheels in a lathe, will require a put on two spokes, the third has to be strained conster-frame to fix in the slide-rest, on the principle of one figured and described in No. 245 ENGLISH ME-siderably to come to the hole on the inside.-A WHEEL ASIC, Dec. 3rd, 1869, only, in place of the round-edged tter H, which is there shown for grooving taps, he Il want a plain circular saw for cutting the notches. he wants to cut and round the teeth at the same time, inust have a cutter of suitable section; 14in. diaeter is a large size to cut in lathe, and he would have put blocks under his headstocks to raise his 54in. the to 7in, in order to do it at all. The larger the dision-plate the more likely is the result to be good; and should not advise, at any time, the use of a plate of ss diameter than the work to be done. Consequently, think that even under the most favourable circumances-that is to say, with the best of tools-his requireents are beyond the capability of his lathe.-J. K. F. QUERIES. [6875.]-BINDING WITH INDIA-RUBBER.—I shall be glad if "Ab Initio" will inform me whether the plan of binding by cutting the backs of the sheets and bindng by means of gum elastic-india-rubber-is lasting; if so, how is it done? I read some years since of the above method having been introduced, but have not heard how it succeeded.-AMATEUR PRINTER. [6876.]-MEASURING, ETC.-1 shall be obliged if any of your readers will inform me how to work out the following dimensions of a ballast heap:-Bottom circumference, 93; crown circumference, 34'; height, 7 6"; total in cubic yards ?-GREGORY. [6877.]-PHOTOGRAPHIC.-Will any of your photographic readers be kind enough to answer for me the following queries:--Supposing I have a new 30 grain negative bath of 18oz. and take twelve plates, carte de visite size, in a day, how soon shall I have to add fresh silver; and what amount of silver will the bath lose by the preparing of the twelve plates? What amount of silver will a printing bath (of 60 grains to the ounce) lose by the silvering of six sheets of albumenized paper, supposing the bath to consist of 12oz.? I have evaporated an old negative bath, and obtained therefrom about oz. of a yellowish flaky substance, with some crystals in it. Can I use this for my printing bath; or does it require any further treament?-S. T. [6378.1-HEADACHE.-A friend has been afflicted with this complaint for several years, and has consulted medical men, but failed to secure a permanent cure. It almost invariably attacks him after breakfast or dinner. I am induced to insert this (with your permission) hoping that a remedy may be secured from some one of your numerous readers.-G. L. [6379.]-GLASS SILVERING.-Can any of your readers inform me of an easy method of silvering cut glass, more particularly flat surfaces, such as plate glass?-WM. JONES. [6880.]-MANGANESE BATTERY.-Will "Signus," or Mr. Fox, kindly tell me how often the manganese WRIGHT. Engine" but I believe his result is wrong; it shows a loss of effect for the rotary engine, and that I do not believe any more than that there is such a loss with a crank.-F. P. [6894.]-ETCHING ON EARTHENWARE.-I have seen some black glazed earthenware jars that have been embossed; the designs have been traced out with Brunswick black, or something, to resist the acid, and when this is washed off it leaves the scrolls bright, while the rest of the article is dull, as though it had been roughed, after the manner of glass embossing. If any one will give me an idea how this is done I shall be obliged.-A POOR STUDENT. [6895.]-STILL FOR GENERATING CHLORINE GAS.-If any of your clever correspondents could furnish the proper proportions for the parts of a still suitable to generate chlorine gas for bleaching purposes, at present requiring about 5 cwt. of chloride and lime daily, or give address of makers of such stills of best form and material, applicable in a mill where steam is at command, they will much oblige-A WORKER. [6896.]-SEWING MACHINE.-I am fitting up a sewing machine on the Wheeler and Wilson principle, but am at a loss to know the following:-First. What use is the spring-like blade that is soldered underneath the cloth plate? Second. Has the rotating hook any steel about it? Third. What is the proper shape of the spool ring or holder, and how to fit it?-RIBBLE. [6897.]-CHLORIDE OF SILVER.-Can any reader tell me how to dissolve chloride of silver made by putting salt into a solution of nitrate? I have tried weak nitric acid, and it settles at the bottom, the same as in water.-J. W. T. [8898.]-MERCURY.-I want a liquid substance, about five or ten times as heavy as water, that will not be effected by water; mercury, no doubt, would answer the purpose, but it is too expensive; but does mercury affect water at all, say in ten years' time ?-MARS. [6899.]-BOAT-BUILDING.-Will you oblige me by inserting the following queries in our paper? 1st. In clincher built boats, skiffs, &c., is any cement or other material put between the planks to keep out the water and make them tight joints when nailing together, or does the paint or varnish afterwards put on do this? 2nd. With what tool are the planks at their edges bevelled to make them lay together? 3rd. Are the ribs of clincher-built boats steamed to shape, and how is it done ?—A. A. [6900.]-SURVEYING AND MENSURATION.-Will some one please explain the following? R. M. KEYBOARD.-Will [6888.] ORGAN one of my fellow-readers tell me how to varnish the ivory? The Also [6901.]-COPPER COIN.-Can any one oblige me with keys are quite new, but the polish is gone off. the cause of several of the pipes in my organ slightly date, value when coined, and present value of coin deCoin probably Roman, bronze, about speaking? When I touch the one note I can detect the scribed below? Obverse:-Three Roman next pipe slightly speaking; for instance, if I touch the the size of our farthing. soldiers, with helmets, spears, and short coats, and middle, the next pipe C-sharp or B would be heard, say, quietly speaking. It is no fanit in the trackers or pull-reading, of which IOR is only visible on the left-hand side, and VS on the right-hand side. Reverse:-Man's downs, as one key clearly pulls down one pallet. fancy it must be in slide. I find it more in the stop head, with laurels and very prominent nose. Reading illegible.-ALPHA. diapason than any other stop.-GAMBA. I [6890.]-PARABOLIC SPECULA.-Mr. Tydeman, in a recent number of your paper (reply 1475), said that there were several very nearly perfect methods of giving the true parabolic figure to a glass speculum. Will he kindly direct me to the systems he means or recommend one that is likely to come within the limits of my own capabilities, for I cannot afford to construct any machinery such as is commonly recommended in works on astronomy? Will he also inform me how to obtain glass discs, dished to the proper curve.-A WOULD-BE ASTRONOMER. [6891.]-ACHROMATIC OBJECT-GLASS.-I have an achromatic object-glass, 18in. aperture and 6in. focus; I frequently see opera-glasses for sale, warranted with several 4-lens eyepieces; but the opera-glasses I refer to 10 and 12 lenses; I am acquainted with, and have made are generally not above Gin. or 7in. in length, when drawn out, and the 4-lens eyepiece of itself would be that length. I have conned over my MECHANIC back to Vol. III. and there is the only 3-lens eyepiece I can find, which is composed of three double convex lenses of in. focus, lin. apart with small stops between. But is this not bad for spherical aberration? Will some of our kind optical friends help me? I do not want a concave eyepiece; but I want the greatest power I can get, say 12, within a compass of about 9in. Will 3 in. plane convex lenses do, placed doable their focal dis tance apart?-ANOTHER BINDER. [6892.]-RE-HAIRING VIOLIN BOW.-Would some reader inform me of the best way to re-hair a violin bow? I have had two or three re-haired at different music shops, but they have never been equal to new. The hair is not lying even and flat, and not being all of the same tension. I can buy the hair, and can also fix it in the bow; but I want to know how to get the hairs of an equal tension, and to make them present an even surface to the strings of the violin.-XIX. [6693.]-POWER OF STEAM ON A RECTANGULAR PISTON.-Will some correspondent show how to cal culate the theoretical power of steam on a rectangular piston moving in an annular space? Tredgold gives an investigation of this in his book "On the Steam [6902.]-OIL PAPER.-Can any brother-reader inform me how the oiled paper used for wrapping blacking in is prepared ?-D. GARDNER. [6903.]-BAROMETER TUBE.-How many pounds of mercury is required in a barometer tube, the tube being one of those bought in a chemical instrument maker's shop ?-T. H. SOMERVILLE. [6904.]-DECIMAL BALANCE.-Will Mr. Davis, or some other reader, inform me how to make one of the above balances for chemical purposes; the tools to be used to be in the hands of one not acquainted with the highest class of instruments? My three points of ignorance are:-1. Must the beam be divided. 2. The length of beam. 3. How is the turning edge constructed. I want a balance for the quantitative analysis that a chemical tyro can indulge in-such as amount of lead in PbA and mineral salts. An answer to my queries would much oblige, but a whole description would be preferred.-T. H. SOMERVILLE. [6905.]-SUGAR BEER.-I am about to remove to the back settlements of a colony where carriage is a great difficulty, and being accustomed to beer as a beverage, I shall have to brew it from sugar, as malt is not easily procurable. Will you let me ask for instruction how to proceed; and the proportions of sugar and hops to water for both ale and table beer? Perhaps some initiated one will also tell me how much sugar is considered an equivalent for a bushel of malt; how much molasses for a pound of sugar; and how much hops is used to a bushel of malt in ordinary brewing.-EMIGRANT, 6906.]-PEDAL HARMONICS.-Will "H. G. W. B." give a short explanation of the chords used as pedal harmonics? The book I am studying says that to comprehend them clearly it is necessary to leave the pedal note itself out of consideration, and treat the lowest of the upper part as the real bar. Now, what can guide me in the selection of the lowest part? Can I make any part the lowest, provided I do not transgress the rule about fifths and octaves, &c., or must the lowest figure always mean the lowest note? Please tell me what chords the figures 2, 4, 8; 2, 7 mean, when placed on a dominant pedal note-say G; also, 4, 5; 8, 7 flat, and 3, 4, 6; 4, 7, on tonic, &c.-say C; that is to say, what do they represent after the pedal note itself is disregarded? This chord of 4, 5, puzzles me very much. VERTUMNUS. [6907.]-AERIAL MACHINES.-Will some one inform us of the results of fair experimental trials of screwpropellers in the air ?-QUERIST. 624 ENGLISH MECHANIC AND WORLD OF SCIENCE.-No. 312. [6908.]-TELESCOPE (STANDS.-Will one of our astronomical friends give me the diameters and thickness of the several parts of Mr. Browning's stand for reflectors' equatorial, same as is figured in his "Plea for Reflectors" (it is to be a 6in. mirror), the hour circle to be 12in? I have not the opportunity of seeing one, and I cannot make the measurements of the woodcut agree. A MECHANIC. [6909.]-MAKING GOLD TOUGH.-Will any one tell me the way to make gold tough after it has been alloyed with copper and silver, as I find it is very brittle. J. W. [6910.]-WORM-CASTS IN TURF-PLOTS.-Would any of your readers kindly suggest a means of destroy ing worms, or of preventing them from throwing up casts? I have a plot of turf which is completely disfigured by them, and no cure that I have been able to think of has proved successful.-AMATEUR. [6911.]-COAL.-Will any of your readers give me their opinion how much coal should be burnt under a Cornish boiler to drive a 12 horse-power engine twelve hours ?-ASSOCIATE. [6912.]-DISCOLOURED TURQUOISE STONES.I shall be glad to know how to renove a green colour which is spreading over some fine turquoise stones? ASSOCIATE. [6918.]-THE ARIEL LEVER BICYCLE WHEEL.Will your correspondent, "A Bicycle Rider" (let. 1516, p. 569), kindly inform "J. H." and other subscribers by stating how many miles per hour he has accomplished on the Ariel Lever Wheel Machine, and for how many hours successively? also what is the size and weight of each wheel? and the weight of the entire bicycle would, I feel sure, be interesting to all bicycle riders.-J. H. [6914.]-MEDICINE PHIAL.-An apparatus or tool is employed in the American glassworks for making medicine phials. I wish a brother reader would give some particulars about that apparatus ?-JOHN D. [6915.]-EQUAL BISECTRICES.-If in a triangle two bisectrices are equal, this triangle is isoceli-a geometrical proof of this theorem is desired?-E. B. S. [6916.]-AIR-TIGHT TEMPORARY JOINTS FOR RETORT.-What can be used to make temporary joints in an iron retort heated to a red heat, air-tight, which will have no chemical effect on the contents ?W. F. M. W. [6917.] QUALIFICATIONS OF AN EXCISEOFFICER.-What are the requirements necessary to become an excise-officer, and the salary ?-J. E. W. [6918.]-SMALL TENT FOR EXCURSIONS.-I want to make a small portable tent for boating excursions. Any one who will kindly tell me the best shapes, and how to render canvas or calico water-tight for that purpose, will greatly oblige me.-C. R. G. [6919.]-THE HONEY DRY-PLATE PROCESS.-I have been trying the honey dry-plate process described some time back by your correspondent, H. Booth, and find the solution of honey and silver turns quite black in a day or so. Is there any method of keeping it which is the best accelerator ? Glycerine in the bath is said to have that effect, but I feel dubious about putting such a substance into a good negative bath, want something to use occasionally for very short exposures, as children, dogs, &c., &c.-SHOPMATE. I [6920.]-PLASTER BUSTS.-Will some brother reader tell me the best and most effectual method of making plaster of Paris busts (such as sold by Italians) washable, and give them the appearance of Parian marble; also how they are bronzed?-FIDE. [6921.]-HYDRAULIC PROPULSION OF SHIPS. b x d2 b x d3 Tib= [6929.]-HYDROGEN.-Will any chemical friend in- called) worn over the mouth and not over the natural [6933.]-COLOUR FOR YACHT'S BOTTOM.-Will [6934.]-SMALL FAN FOR FURNACE.-Can some best way to construct a small fan for furnace or forge? it to answer.-J. BIRCHALL, [6935.]-CUTTING WOODEN TEETH IN COGWHEELS.-Will any fellow-reader kindly inform me the best method to cut wood teeth to cog-wheels? Can it be done with a band saw? The teeth are about 4in. long for mill work.-РEM. Dock. of [6936.]-INDUCTORIUM'S COIL.-In the description [6937.)-BUNSEN'S BATTERY.-I thank Mr. Tonkes [MAR. 17, 15 moderator by which the shock can be applied strong, but I am at a loss as to the constructi bands.-G. WILLIAMS. MACHINE.-Will some kind reader of the E (6944.] ARMATURE OF MAGNETOLI MECHANIC inform me of the way to coil the of a magneto-electric machinery? I have tr cannot get it to produce any sensation in the operator; and I believe the fault is in c RHONDU. [6945.]-FIRE-BOX OF BOILER-May I correspondent "Jack of all Trades, vision he makes space round boiler from burning, as there appears to prevent the fire-be the fre? What gauge of would he advise for a boiler; a gauge of rivela 18in. diameter, and distance between each rive plan shows no fire-door. Some years since 12 corrugated double shell riveted would prev strong boiler. I should like to see "Jack of all Tbciler well stayed before experimenting with flanges or angle iron.-C. T. of 8,000lb. to the inch. His joints are laid DOMESTIC RECIPES. (From the Food Journal), liver; cnt it into thin slices; place it, with a bit of NORWEGIAN OATMEAL PORRIDGE.-Tak or three handfuls of meal, mixed, coarse, and Could any fellow-reader say how it is we hear nothing maximum number, and not add the cotton-covered wire proportion of one third latter to two of the former. I of the hydraulic propulsion of ships now; a short time ago it was to eclipse everything? What has become of the Nautilus and Waterwitch? they were said to answer at the time. My object is to be enabled to decide on the relative suitability of the paddle, screw, or hydraulic propeller for a small boat.-J. M. C. [6922.]-SLIDING SCALE.- I shall be glad if any of your readers can inform me the name and purpose of a sliding-scale I have in my possession-12in. long, with two sliding-scales, figured both sides; also a barrelslide, figured and marked on all its eight faces: the grooves also are all figured-such words as:-cube, side, gunpowder, sol, globe, icofaedron, meridian, rum, ale, marble, steel, and many abbreviated words, with a profusion of figures entirely covering the instrument. I gather from these that it can be used by surveyors, gangers, astronomers, engineers, &c., but shall be glad to hear if it is a known instrument. I have never seen one before, and an engineer I showed it to this morning was also ignorant of such a measure being in existence. It is marked, Ios. Suxpeach Inor. Ratcliff, 19th Feb, 1753. Ben. Parker, fecit.-INQUIRER. [6923.j-PORTABLE TURKISH OR VAPOUR BATH. -I should feel very pleased to see simple instructions in the ENGLISH MECHANIC how to make a portable Turkish or vapour bath; and what would be the best heat to apply? Would gas do; and, if so, in what way should it be burned?-T. B. [6924.]-HOT AND COLD WATER CISTERN.-There is on the top of my bath-room a large iron cistern to hold hot and cold water, divided by a partition of iron, fin. thick, and I should be glad to know how to prevent the hot water heating the cold water. Would an additional partition do; and, if so, of what material, and how fixed ?-SHOWER-BATH. as recommended. I shall be glad to see Mr. Tonkes' acid fumes.-CURRENT. [6938.)-SPEED PULLEYS FOR TURNING WOOD. -Required the dimensions of speed pulleys for turning wood, brass, ard iron respectively, with a driving-wheel of 3ft. diameter revolving once per second.-J. ADAMS. CINGS.-Will any brother subscriber kindly tell me [6939.]-MOUNTING AND VARNISHING TRAhow to properly mount and varnish tracings for the workshops ?-Y. Z. [6940.]-ARTIFICIAL ROCK-WORK.-I built some artificial rock-work last year of coke, &c., and coated in a basin of cold water and pour into a pan conta about a quart of boiling water, adding a small p of salt. Set on the fire, and keep stirring, s from time to time small doses of meal until it bris has acquired a proper consistency; which m known by its glutinous state, as it drops from spoon. Let it simmer ten minutes, then pour common dinner plates. Spoon ont portions, and in new milk, adding sugar to taste.-J. F. UNNOTICED QUERIES. In order to economize space the numbers and titles of unanswered queries will in future be inserted only once. We trust our readers will look over the list and send what information they can for the benefit their fellow-contributors. [6941.]-WHITWORTH'S 5IN. LATHE.-To "J. K. Since our last J. Hirst has answered 619: "Fes [6925.]-CHEMICAL AFFINITY.-TO "SIGMA.""Sigma," in let. 1869, says that carbonic oxide and iron and hydrogen and palladium unite in similar manners. [6942.]-MUSIC.-I should be glad if any musical I would feel particularly obliged by information as reader would kindly give the names of a few choice to where I may be able to learn particulars of this?-trios, quartetts, &c., by Correlli, Haydn, &c., easily arranged in 1, 2, or 3 sharps, suitable for an amateur musical party of 1st and 2nd violins, flute, cornet, cello, and piano. Also the names of any quadrilles, waltzes, &c., arranged in the same keys. No doubt the above desired information would be very acceptable to many of our musical subscribers.-CORRELLI. G. Y. M. [6926.]-BLUEING WATCH HANDS.-How can I blue watch and clock hands ?-SYDNEY CARTON. [6927.)-SOFTENING STEEL PALLETS.-Can steel pallets be softened for filing, and afterwards rendered quite hard for use, and how ?-SYDNEY CARTON. [6928]-VELOCITY OF FALLING BODY.-Will any reader of the MECHANIC kindly tell me the velocity a falling body has acquired at the instant of passing a point the one hundreth part of a foot below the point of departure; and the time in decimals of a second in alling the above distance ?-J. MASON. |