in Germany is produced by the addition of a certain amount of the flesh of the horse or donkey; this addition also makes them keep better.-T. R. ALLINSON, L.R.C.P.

[53094.]-Beef Hams.-Flesh usually loses in cooking, unless it be previously dried. Roasting diminishes the weight of a joint of meat about 20 says boiling does the same. If per cent. "Fluid there be a remedy it must lie in the direction of coagulating the albumen on the outer surface of the meat, and so preventing exudation as much as possible. To do this, "Fluid" must plunge his hams into boiling-hot water, not put them into cold water and allow to boil. Or he may try the experibefore plunging into hot water. This forms a hard ment of brushing his hams over with white of egg covering for them, and may prevent exudation. If these fail him, let him try steaming them as potatoes are done. If any of these means succeed, I shall be pleased to know which, as the knowledge will be useful in economic cookery.-T. R. ALLIN

SON, L.R.C.P.

-

cron

[53106.]-Fancy Photographs. If "Omi" will write with a weak solution of sulphate of copper with a clean quill pen and then dry, he will have an apparent piece of white paper. Expose this to the fumes of strong ammonia, and the writing appears blue. This colour fades as the ammonia evaporates, and may be reproduced indefinitely.-T. R. ALLINSON, L.R.C.P.

-

[53111.] Parchment Paper. What does "Os" mean in recommending the querist to use Swedish filter paper for making the above? Doesn't he know that filtering paper is much the same as blotting paper? If so, how does he imagine that it will produce a paper with a surface similar to parchment? The correct method is as follows:Dip ordinary unsized paper into dilute sulphuric acid (1 in 10) for a short time (about a minute). Then wash well with very dilute liquid ammonia to remove all traces of acid. If "Os" manages to make a parchment paper from filtering paper, will he publish his method for the benefit of "ours"?

-CHEMICUS.

[53112.]-Violin.-I have been anxiously waiting for the reply to this query, and am disappointed with that given by Mr. Andrew. Several tools for purfling violins have been described in back numbers; but having tried them all, I have found them more or less failures. They have, however, all been better than the primitive tool Mr. Andrew recommends, being made on the principle of a marking gauge with two thin steel cutters. If Mr. Andrew has ever purfled a violin in the way he describes, he will agree with me that it is a very long and very unsatisfactory job, and at the rate paid for violin making by the wholesale makers, a man would not earn his salt by that process. I have before me the prices paid by a wholesale violin maker in Paris, and I find that for the workmanship of a very good violin body he pays 1s. 44d. This includes cutting out, shaping, and fitting up, and this is a purfled instrument. My idea is that the groove is cut out with a revolving cutter; but I am seeking information on this point and shall be glad to receive it from some reader of "ours."YOUNG VIOLINIST.

[53116.] Telescope. I should recommend "Longworth" to communicate with Grubb about his telescope, and I have no doubt he will get every information. Perhaps "Longworth" bought his telescope secondhand, and some of the glasses may have been changed. I cannot think that Grubb would sell an inferior article, as he is the best telescope maker of the present time.-C. M. C. [53121.]-Weight of Flywheel.-The only loss of power occasioned by the substitution of a fly-61b.), cost 10s. to 15s. wheel weighing 7 cwt., in place of one weighing only 4 cwt., would be caused by the greater friction on the bearings. The heavier wheel would make the engine run more smoothly, and in virtue of its attempt to change its velocity, such as might occur superior momentum would overcome any sudden in sawing wood.-SWASHBUCKLER.

[53121.]-Weight of Flywheel.-G. L. Scott's answer to this query, although true in one sense, is scarcely a sufficient one. It all depends upon the kind of work. If the work is regular, nothing will be gained by increasing the weight of the flywheel. If, on the other hand, it is irregular, an increased weight of flywheel will be a gain, and the more irregular the work, the more may the weight of the flywheel be increased with advantage. WYATT.

W.

[53126.] Magneto - Electric Machine. Make a flat coil of insulated wire that will just pass between the opening in the ring. Note which is at present the N. pole of the magnet, send a current through this wire, moving the coil several times all round the ring, backwards and forwards, taking care that the current travels in such a direction as to retain the original magnetism; id est, so that while the N. pole is uppermost to your left hand, the current passes over the ring, away from you. A small ivory or bone stud, not above in. in diameter, and in. above the level of the split ring, screwed into the split ring of the commutator, at half way between the division line, will act as an interruptor, and may be removed when a continuous current is wanted for any purpose.-S. BOTTONE.

easy to do properly, and most beginners make a hash of it the first time they use it. I use "Cheshire rakes" for fixing. In no case must a swarm be put into a hive with every frame filled with foun. dation, as the weight of the bees will entirely depend on the wax sheets, and a collapse will be the result. Some old combs should be alternated with the sheets of foundation. Having procured the hive, the cheapest way to stock it is to wait until May or June, and purchase a natural swarm (weight 3 to contented for the first year with the experience "Economist" should rest gained by keeping one hive, and should remember that he may in time make beekeeping pay if the bably be disappointment.-ALFRED WATKINS, HOD. capital expended on each stock does not exceed £1; but if it runs up to £2 or £3, the result will proSec. Herefordshire Bee Keepers' Association.

[53129.]-To Coppersmiths. If "Coppersmith" had given size of copper globe, one would have had an idea to work on; but if not too large, say, 2ft. 6in., he had better work up his two halves, then lay his flange back and divide each part into four, then cut with sharp chisel. He will find this the simplest way.-T. CLARKE.

[53131.]-Dumb-bells.-I should recommend to you Indian clubs in preference to dumb-bells, for the former you can have more heavily weighted too heavy for you in the first instance. Ascertain, when you progress in strength. Do not use a pair by actual trial, the weight that suits your strengththe weight that you can lift with comparative ease. At any future time lead can be added to them. In practising with them (best done either upon rising any fatigue consequent upon their use. You will or retiring), cease the moment that you perceive find suitable exercises detailed in "Maclaren's Physical Education," where is also to be found a list of the self-measurements you desire.-DEVONSHIRE

SQUIRE.

from 34in. to 36in. round the chest for his height. [53131.]-Dumb-bells.-T. W. Smith should be Not having my books beside me, I cannot give exact figures. Dumb-bells are useful, but must be light ones to begin with; say, about two pounds each, to in the gaslight through the town is not caused by Rowing is good for the muscles of the back. To [53127.]-Gas Engine.-Evidently the jump be used night and morning for five or ten minutes. the quantity of gas absorbed by your engine, as develop the chest muscles T. W. Smith can rig up you state, there is a meter supplying engine, and a simple yet good contrivance: Get a couple of the check or backward tendency is thereby stopped. small blocks, suspend them from the ceiling or The fault lies amongst one of three sources, either other convenient overhead place, to be about half a water getting into mains, faulty construction of yard apart. Pass a piece of rope over the pulleys mains, or mains laid close to surface, and conse-long enough to reach the ground on one side and to quently affected by the vibration of passing trains, reach just above the head on the other side. To trams, &c. Such would also affect the gas in your each rope end touching the ground fasten a weight workshop. This will easily explain second part of of four pounds, to the other end a piece of wood to query, as gas is not supplied through same pipe catch hold of. Grasp the ends above the head and for engine and workshop. Evidently the irritation pull downwards until the hands are level with the is from an outside source, since when filling gas-bag breasts, then slowly raise them above the head and shutting off disconnection the jump still con- This is imitation bell ringing, and develops the tinued.-JNO. C. GILROY. muscles of the front of the chest. T. W. Smith time.-T. R. ALLINSON, L.R.C.P. might turn volunteer with advantage if he has the

[53128]--Bee-keeping.-If you are an "economist," and have never kept bees before, your best plan is to shun all such things as foundationmaking, small colonies, hybrid queens, and Langstroth hives, and begin by begging or purchasing a good large swarm in May, and putting it in straw skep, with a hole in crown. Observe and study them well, read up in the matter, and get used to the working of them. Make a bar hive or two during the winter, and transfer them next year. This will suit your requirements in every way, and will be the truest economy.-J. I. S.

[53128:]-Bee Keeping." Economist" is so evidently a tyro who is placing too much reliance on the statements in some hive maker's catalogue, that I think I can be of most service to him (and perhaps to other beginners) by telling him what not to do. If he were an experienced man, keeping 50 or more hives, it might pay him to purchase appliances for comb foundation making-not without." He must try no experiments, building up weak swarms, and introducing queens the first year, as he would probably lose the lot. He must give his friend the hive maker a wide berth if he wishes to "add to a very small income," and 10s. must be the outside price he should pay for a complete bar-frame hive. Any sum over this paid for a fancy hive is simply wasted. The Langstroth hive is the standard bar-frame hive of America. It is much the best in England to adopt a hive fitted with the British Association standard frames. "Economist" must remember that to earn money at any branch of farming (and bee farming is no exception), a considerable amount of experience is necessary, and he must be content in his first year's bee-keeping to proceed slowly, with little hope of profit. Now, as to the best way to proceed, let him get a modern bee manual for information, and look up the subject in back numbers. If he can do a little carpentering, he can make a hive for himself at a cost of about 2s. 6d. ; he will find full details at p. 340, Vol. XXXVII. (I may mention that these tea-chest" hives have been thoroughly successful both with me and other people). He must refer to his manual for instructions how to fit wax guides or comb foundation. The latter is not

[53131.J-Dumb-bells.-To T. W. SMITH.→→ The following remarks, based on personal experience, will, I hope, be of use to you. First, if you could possibly contrive to attend a gymnasium, say once a week, I think you would not regret the time so spent. Failing that, you might use dumb-bells not more than 4lb. apiece in weight. The best time would be after your morning bath, but not going on long enough to feel tired. Next try and get hold of a cavalry corporal, and get him to show you the extension exercise they use for "setting up" their recruits. Practise that for two minutes on getting up, and again just before going to bed, when you are not encumbered with braces, &c. You will find it tend to develop the chest and prevent stooping wonderfully. With regard to the ratio of chest to height, no hard-and-fast rule can be laid down, as so much depends on the man's build. I daresay you may increase your chest three or four inches. If you live in London, and will advertise your address, I will send you mine, and if you care to call on me, will teach you the exten. sion exercise with pleasure.-A. A. M.

[53132.]-Earthshine on the Moon.-I observed the brightness of the limb of the moon illu minated by the earthshine on Feb. 29. I think it is due to the angle of illumination; the brightness is caused by the visibility of the radiating streaks, whatever they may be; only, as seen at full, this brightness of the moon's eastern limb is, of course, more readily observable.-J. C. L. M.

[53132.]-Earthshine on the Moon.-When we consider that the earth, moon, and sun are at new moon nearly concentrical, and that the moon is near the middle of a band of parallel rays from the sun 800,000 miles in breadth, it is not difficult to see that some of those rays overlap the horizon of the moon, and cause that ring of light which some people describe as the young moon in the old moon's arms.-R. B. G.

[53142.1-M.R. Engines.-To "AVON."-Yes, Leeds engines did work trains as stated by "Avon." Their numbers were at the time 40, 41, 42, 70, 71,

=

theoretical power obtained energy lost by descending column of water. 330,000 foot-pounds gain = 330,000lb. loss of energy of water; but 330,000 with 200ft. of a head, = 1,650lb. of water 200 required, and 10lb. 1 gallon; .. quantity, of water required to obtain 10h.p. with a head of 165gal. per minute. This would be the case if the motor had 100p.c. efficiency; but that is impossible. Knowing the efficiency of your motor, you can calculate by means of a simpleproportion sum the quantity you require.-SWASH

200ft. =

BUCKLER.

[53177.]-Tangent Galvanometer.-You can take the absolute measurement of current by tangent galvanometer if the "constant" of the instrument is known. The radius of the coil divided by its total length (measured in centimetres), and multiplied by the horizontal component of the earth's magnetism, then multiplied by the tangent of deflection; or, in brief, c=r/1. H. tan. of deflection, where equals radius of coil and its total length. Another way, if the "constant" of the instrument is not known, connect a standard Daniell's cell and rheostat in circuit with galvanometer, make total resistance in circuit, including res. of cell and galvanometer, 1,079ohms, and [53172.]-Peculiar Clock.-"Already Obli- note angle of deflection, take the tan, then to find gated" must have strange notions of mechanics to the strength of any other current passing through fancy such a clock as he saw in Hackney works by galvanometer alone, observe deflection and tan.; electricity. It consists merely of two discs, carry-divide latter tan. by former tan., and result gives ing the hours and minutes round, which are shown strength of latter current in milliampères. To through slots cut out of the dial, instead of carry bring it to ampères divide by 1,000.-LE PRINing round the hands on the outside of the dial. It would be a novelty indeed if the writer could cause electricity to carry round these two circles. Has not the writer ever seen this done for showing the hours and days of the month on some of the old eight-day clocks in London and the country? W. B. CRISP.

TEMPS.

=

UNANSWERED QUERIES.

cered for five weeks are inserted in this list, and if t The numbers and titles of queries which remain una unanswered are repeated four weeks afterwards. We tru our readers will look over the list and send what informatic they can for the benefit of their fellow contributors.

Since our last W. Robinson, jun., has replied t 52557, 62546; "H. T. W.," 52803. 52579. S. E. Engines, p. 395. 52587. Incandescent, 395. 52588. Fireclay Furnace, 395, Boring Head, 395. Elliptograph, 395. Engine for Boat, 395.

52590. 52591. 52596. 52557.

Soldering Joints of Gutta Buckets, 395

52610. 5:614.

52615. 52321.

Paper Scenes, 393. Copper Reduction, 395. Chromoscope, 395. Siemens' Dynamo, 396. 52622. Oxyhydrogen Lantern, 396. 52625. Field-glass, 396. 52637. Dogcart, 396. Gumming Machine, 396. Manganese Battery, 396. Drain, 396. Negative Plates for Bittery, p. 482.

52650.

52893.

Lantern Lenses, 482.
Moving Lantern Slides, 482.
Improved Carrier for Lantern Slides, 482.
Circular Saw on Lathe, 482.
Stained and Coloured Glass, 482.
Photographing Gas Flame, 482.
The Action of the Pump, 483.

52910.

52921. 52923.

Microphotography, 483

J. I. S.

[53175.] - Dynamo.-To MR. S. BOTTONE. 1st. Two little metal hooks, at same distance apart as the platinum rings of the lamps, protrude from any wooden stand or bracket; the other extremities of the hooks terminate in binding-screws, to which the leads are attached. To insure the hooks making good contact with the rings of the lamps, a spiral formed of a few turns of thin, but springy, brass wire, is fastened to the stand or het, so as to eucircle the two hooks. The the lamps hook on to the two hooks, a . so doing push down the spiral, which there' tends to keep the hooks and rings, or eyes. close contact. 2nd. About No. 16, indiffere with gutta or cottonlatter cheaper. 3rd. Armature not to exceed 3,000 revs. per minute. It will not light one lamp, unless resistance be inserted as a shunt; but on the main circuit it will light four 5-candle power Swan's. 3rd. Don't know exactly, depends on pressure of gas; say from 12 to 14-candle power. 4th. Put on four 5-candle lamps. Please remember that this dynamo is not constructed for continuous work, as it gets too hot.-S. BOTTONE.

[53178.]-Granule Cell.-I do not know the resistance of this cell; but you can easily measure by tangent galvanometer thus: Insert the cell to be measured in circuit with tan. gal. of low resistance and rheostat. Observe deflection, take tan. when only res. of cell and gal. is in circuit, and then by means of rheostat, add resistance until a deflection is obtained where tan. equals one-half of former tan. The resistance so added will be equal to the res. of cell and gal., and knowing latter, by subtracting it, we get the former.-LE PRINTEMPS.

[53179.]-Ohm's Law.-The diagram referred to by "Practical" is quite correct. If he will read the text, he will find the explanation as clear as the diagram.-C. D. S.

[53179.]-Ohm's Law.-The diagram in Ferguson's book, is quite correct. If the whole battery of 9 cells be taken it will work as three cells each of treble the capacity on one cell, but of course if you take only three cells, it will give on a short circuit the current of one only, but the E.M.F. of three cells.-ELECTRO, Manchester.

[53180.]-Dynamo.-To MR. S. BOTTONE.-1st. Not necessary. 2nd. A reply to this would be an advertisement. Several good electric wire manufacturers advertise in our pages. Buy of the manufacturer only, and you will not be far wrong. 3rd. Instructions are given on this point in current number. 4th. Quite safe; but you must insert about 12in. of No. 36 iron wire as a shunt between electrodes of the dynamo, so as to get heat effects. More details as to this will appear About 100 rev. of the armature per minute will then give ample current for the coil.-S. BOTTONE. [53182.]-Dynamo.-To MR. S. BOTTONE.-Quite as good, even better, because it can be driven at a higher speed. But please remember you must not drive for more than 15 minutes at a time, or else the iron gets hot, owing to the Foucault's currents, and the insulation breaks down, to the ruin of the dynamo.-S. BOTTONE.

[53177.]-Tangent Galvanometer.-A current flowing in the coil will turn the needle aside through an angle such that the tangent of the angle of deflection is proportional to the strength of the current. The absolute measure of current by the tangent galvanometer is found by the following equation: i= . H. tan. d. The quantity is called the constant of the galvanometer; represents the radius of the coil; H is the horizontal magnetic force; d, the angle of deflection; n, number of turns in the coil.-B. D. WILLIAMS.' [53177.]-Tangent Galvanometer.-In order to measure the strength of a current by the tangent galvanometer, the first thing is to find the constant of the instrument. The constant = radius of copper ring. The earth's magnetic force x the num[53189.]-Drying Box.-I believe a good one ber of turns of copper ring x 6.2832. Having was fully described one or two volumes back. All, found the constant, take a deflection on the instru- however, that is needed is a large box with closement, and find the tangent of the angle of deflec-fitting door, which for extra safety should have a tion; multiply this by the constant, and you have double rebate round it to keep out the light. This the current in C.G.S. units. 1 ampère 1 C.G.S. requires a zigzag passage at bottom and top for the units. N.B.-All measurements must be in the entrance and exit of air, and should be fitted with proper units: Length, centimetre; weight, gramme; shelves fitting the box from front to back, but 3in. time, second. Having found radius of ring in less in length, each shelf thus leaving a space 3in. inches, multiply by 2-54 to give centimetres.-wide at alternate ends of the box for the air to pass. Over the exit at top should be fitted a tall chimney with a lamp or gas flame in it, to cause a [53177.]-Tangent Galvanometer. To mea- draught through the box. I fully described mine sure current by the Tangent galvanometer, the in the Photographic Year-book some years back, and horizontal component of the earth's magnetism HI do not suppose the Editor would care to occupy must be known for the place, at which the current is to be measured. The constant of the instrument space with what is consequently old matter. FINEM RESPICE. must also be known, and is expressed by the formula 2π where r radius of the coil, and π = 3.14159. The full equation for the strength of current is

[53190.]-Chinese Serpents' Eggs.-These are composed of sulphocyanide of mercury, which is generally rolled up in a cone of tinfoil. But the most strange-looking chemical serpents are made with sulphocyanide mixed into a paste with a little thin gum water, and either roughly made into a cone or into small balls. These, when lit, burn with the utmost fierceness, producing a snake of a light or dark brown colour many yards long. If the above is unsuitable, I shall be pleased to give another.-B. D. WILLIAMS.

52924.

Removing Tricycle Wheels, 483,

QUERIES.

153194.1-L.B. & S.C. Ry.-Will any one give m the dimensions of the tank engines like Sydenhan Brompton, Denmark, Stepney, Whippingham, Hoathi Deepdene; and goods tanks like France, Dijon, Lucern horne, Newhaven, Southbourne. Also classes of th Berne, Geneva; and passenger express engines Imber above-RICHMOND.

(53195)-Distillation of Wine.-I have just bee distilling, with Dring and Fage's revenue still, a sampl soon as distillation commenced, the wine became milk of Malaga wine. I added nothing at all to the wine. A and then chalky in appearance, and the in'erior of th retort became spotted and streaked with some opaqu matter like chalk. The distillate also, from the firs was milky, and this milkiness increased as distillatie proceeded. The milkiness in the distillate showed ign of settling, and resembled that caused by sulphur i some chemical operations. Will some one kindly tell m to what I must ascribe these phenomena 1-LABRADOR. [53196.]-Pyrogallic Acid Stains in Marble Can any reader tell me how I can get stains of pyro gallic acid out of marble Some months ago, developing a negative (dry-plate), J cirelessly left som valuable washstand slab; and before it was noticed i overflow of the solutions -Marion's formula-on had sunk into and stained the marble a dirty brow colour. I shall feel very thankful to any one who ca tell me what will remove the stain.-TERRA NOVA.

I

pull beer machine; but it does not lift beer satisfactorily [53197.1-Beer-Engine.-I have fixed a new four having sometimes to take three strokes to pump on gill. It will pump clean water with very little trouble Thinking the suction-pipes being in fault, they bein only in. diameter, working barrel is of brass, 24in. diameter. new put in pipes in diameter; but with very little improvement. height from cellar floor to pump does not exceed 101s Will Mr. P. J. Davies, or some of your readers, kindly explain the cause of the pump not working to my satis faction, and how to remedy the evil!-QUELIST.

- Roasting Jack. Will any of th readers of your valuable paper kindly inform me how t make and fix the inward motion of a roasting jack! The one now in use has been in work for many years. works with a fan and what we term a screw jacklarge screw cut upon the upright spindle which work into an appropriate cog which turns the outward motion,-and I am thinking of renewing the inward motion; and I should like to know the simplest and best way to do so, believing that there are modern in ventions which will suit much better than the presen one.-ONE IN A FIX.

(53200.)-Marking Cogs.-Would some one kindly instruct me how to mark off cogs upon a wheel. I hav made a wheel 14in. diameter, and I want to make on difficult to do; the small won't work in the large. Perhap 4i0. diameter to match (mitre cog); and I find it very some kind reader would help me out of the difficulty And which is the best way to mark off plain square cogs -ONE IN A FIX. [53201.]-Legal-Income Tax.-Can some lega gentleman of **ours " say how subscriber should proceed in following case! At proper time he claime exemption on ground of total income being £140. way recognised as a correct return of income; bu been made upon the remaining £20, after abatemen quietly ignoring right to exemption, an assessment ha being allowed for £12. Can payment of this illegal s sessment be enforced and if so, can the assessed har any redress ?-I. POTEST,

That

[63202.]-Dynamos.-Is it possible to join tw dynamos together so as to send their united current

round a circuit, in the same manner that the currents of two Bunsen cells would be sent if the two zincs were joined to one end, and the two carbons to the other? If 80, will some one kindly say how the connections should be made? The dynamos have each four terminals connected with the two ends of armature and field-magnet coils (De Meriten's C pattern).-R. G. J.

INNER..

(53203.)-Earthwork-Would any correspondent kindly explain the formula for calculating volumes of earthwork called "The Prismoidal Formula"!-A BE[53204.1-Water Power for Sawmill.-Having an available stream, I shall be much obliged by any information respecting the minimum diameter and breast measurement of an overshot waterwheel to drive a ircular saw requiring at least 8-h.p. Please to state he minimum area and depth of the reservoir, with the lepth below the surface of the water for the pipe or leat eading to the penstock. Would the power be better ommunicated from the waterwheel to the driving pulley by spur or bevel or band connections ?-SHADOWLESS MAS.

[63205.]-Biological.-Will any of your readers favour me with a typical answer at a public examination on the life history" of any biological subject-say of Chara -HYDRA.

[53206.]-Experimental Physics. A jet of rater is projected against a fixed wall so as to strike it it right angles. If the velocity of the jet be 80ft. per econd, and 100lb. of water strike the wall each second, what pressure will be exerted against the wall (1) when he water does not rebound, (2) when it rebounds with a velocity of 10ft. I er second ?-HALS.

(53207.1-Landscape Lenses.-How can I know Dallmeyer single wide-angle landscape lens from an ordinary Dallmeyer landscape lens? The wide-angle ens is said to be composed of three lenses cemented torether. The ordinary view lens of two, also cemented; but, looking at the mount. I wholly fail to discern how nany lenses it is compounded of.-WANDERER.

[53208.-Finding Circle from its Segment. have been to see a fine elm blown down with many thers in Holker Park. Length of trunk from base to rown, 20ft. girth half-way up, 14ft. 4in I wish to find he girth lower down, but the tree is partly buried. Can ot the girth be found from the segment above ground? Sircumference of segment, 10ft. 6in., altitude 3ft. 9in ARGENT SABLE.

53209.]-Governors. Would "Firer, Dewsbury," elb. balls on two pendulums 24in. in length, rising when blige me by answering the following? If I had two unning at 50 revolutions a minute, supposing I took he 361b. balls off and put 181b. balls on the same length I pendulum, what difference would it make ?-IN

UIRER.

(53210.]-Optics.-Would any reader give any rules formula for finding the position of objects and images mirrors and lenses! I have failed to find a guide to is in many books treating on light. Perhaps Mr. W. Grey would kindly answer or name any textbook.IVATE STUDENT.

53211.] To Colour Leather.-Would some of - scientific contributors inform me as to above? I sh to colour a quantity of leather I have, a nice safn yellow-the same colour as rug straps. I have tried veral combinations of some of the aniline dyes; but ve failed to get the colour I desire.-MEDICUS. [53212.]-Boiler.-Wou'd some one kindly tell me e safe working pressure of a copper-riveted loco. type oiler of the following dimensions? Also what sized linder (launch-engine type) she would drive! Outside rebox, 7in. long, 6in. wide, 7 in. high; inside firebox, in. long, bin. wide, 54in. high; boiler Sin long, 6in. ide; whole length 17 in.; 21 in. tubes, brass; to burn de, 4in. deep; ashpan 1in. deep; smokebox 2in. arcoal; in. space of water down side of fire; made f copper 16lb. plate, No. 19 B.W.G.; tube plates fin. nick.-J. B.

(53213.]-Embossing on Steel.-Will some kind ader inform me how to emboss patterns on polished Ceel plates? I have been told to paint patterns with runswick black, and then apply nitric acid. I have one so; but find when I apply acid most of the pattern ill come off, and the little that is left I find acid has urnt through, and took all polish off. Will some one ell me if there is something better than Brunswick lack for painting, or if there is some other acid used? might say I have seen some plates done, and the part ten away with the acid has a very nice frosted appearace.-P. H. P.

[53214.]-The Agricultural Holdings Act, 883.-Will some kind reader oblige with a definition f the word "pastoral," occurring in the 54th section of his Act? The meaning of the whole section is obscure, nd the obscurity is intensified by the introduction of the Ford pasto al to convey some meaning I have never seen plied to it in my limited reading. The phraseology of cts of Parliament seems peculiar to that class of terature, and is such that no fellow can understand, ntil the meaning has been settled by a judge and jury. I the drawers would condescend to write in "English" sixpenny dictionary would supersede law courts in the eaning of the words, and a vast amount of litigation ould be prevented if a spade were always called a

ade.-BLACKBURN.

[53215.)-Engine Query.-Will one of our able ends please say if a 12-horse steam engine with an inlet 3 diameter of pipe, and an exhaust in. larger, ould lose any power by being carried 60ft. from engine. r purpose of warming a room, before reaching outlet? BASSO.

[53216.]-Curb Chains.-Will any friend tell me w the curb chains (gold and silver) are made to lie At The links seem bent in some way.-AMATEUR, 53217.]-Astronomical Clock.-Will some kind respondent tell me the simplest and best way to set 7 clock to Irish time I have a 9in. altazimuth Hector, and my longitude west is 6° 47' 30".-VICAR. [63218.]—Oval Chuck-Will some correspondent

give me directions how to make a simple oval chuck for a common woodturner's foot-lathe ?-ORGAN TUNER,

advice. My third finger on my left hand has become stiff [53219.1-Organ Tuner's Stiff Finger.-I seek in the second joint. When I open my hand it remains at right angle to the rest of the fingers. No pain It has been coming on for two years. Age over 60.-ORGAN TUNER. (53220.]-Attaching Lincrusta Walton to Stone or Metal.-Would any obliging correspondent say if this can be done, and the best method to adopt in either or both instances -TU QUOQUE.

[53222.]-Marking Designs on Glass.-Will any of your readers describe the process, and name the acid, used in working the above? It appears when finished as if done by a stencil plate, and is not etched or wheel worked.-J.

[53223.]-Legal.-TO MR. WETHERFIELD.-A. obtains from B. £100 on a promissory note for six months. A. two months afterwards deserts his wife and family, and is supposed to have gone abroad. A.'s wife obtains a protection order six weeks afterwards, and carries on the business on her own account. Can B. interfere with the business and household effects, or make the wife pay the amount owing to him ?-ANXIOUS.

[53224.]-Dyeing White Coral Rock.-Can any reader inform me how white coral rock could be dyed red, or if it is capable of taking in colour! It seems to be of a porous nature, and I am anxious to see if it could be done.-JAMES ARTHUR.

magnets 10lb. of 20 wire. Cannot get but feeble current. Insulation all right. I have driven it 2,000 per minute. What is the matter?-H. R.

bequeathed to her life interest in one of two houses, on [53239.]-Legal.-To MR. WETHERFIELD.-A. has condition that the moiety of the debt on both houses be paid by her. The portion of the debt consisting of money borrowed on note of hand must be paid up in a few weeks. A. declines to pay the moiety. Conse quently, house must be sold in order that the money may be paid. Can A. claim any compensation from the trustees -C. B.

(53240.1-Dynamo.-To Ms. S. R. BOTTONE.-I have nearly finished the dynamo you have so kindly given instructions for making; but I see by your answers to a recent query that it cannot be worked by power for more than five minutes at a time, it getting hot. If not asking too much, would you give instructions for making one that would take about or h.p. to work it? so that an amateur could light his workshop and two ordinary rooms. I should also like to know how the lamps are connected with the wires. Also how the lamps are cut off or out of circuit.-W. W. E.

[53241.)-Robins in the Garden.-Do robins de as much harm in gardens as sparrows? hand, do they do as much good?-ARCANUM.

"

On the other

[53242.]-Pump Regulator.-I should be glad if Meteor," or other railway correspondent, will give details of the air pump regulator used generally on the N.E. and other engines -HISTORIAN.

[53243.)-Railway Keys.-Wanted details of railway keys used on the Furness and other lines which never fall out of the chairs.-HISTORIAN.

[53226.)-Cobblers' Wax.--Will any reader give a recipe for making shoemakers' (cobblers') wax? I should prefer one for making brown wax; but black would do. Also please say if it is the same as that used by saddlers and harness makers -JACK.

[53227.]-Value of Freehold Groundrent.-A railway company intend purchasing a ground rent of £9 What ought they to pay for it? They have power per year, with reversion (in 50 years) of two cottages. to compel me to sell.-J. WATTS.

[53228.1-Wharncliffe Meeting.-What is meant by this term, frequently applied to meetings held by railway companies ?-W. B. P.

[53229.]-Turning.-I have a lathe by a first-class firm which gives me every satisfaction; but when I use the face plate, I find that in screwing the article in position to be bored, I cannot get the job tightly enough, in consequence of the dog (that is diametrically opposite the one I may be screwing) receding from the centre. however tightly I screw up the set of dogs at back of face-plate. They are provided with washers. I get over the difficulty by inserting plugs of wood in the slots; but this practice is inconvenient, and I shall be glad to know a better remedy.-AMATEUR TURNES.

[53245.] Churchill's Hypophosphites. Can any reader say whether, from experience, there is any danger likely to arise from the use of these medicines, apart from their remedial properties, in cases of consumption and chest complaints—W.

[53246.-Thermopile.-Will any of "ours" give the E.M.F. between German silver and iron, also between copper and iron, when a difference of temperature of 100 Centigrade is maintained between their junctions! method of construction, what effects were obtained, and If any of "ours" have made a practical thermopile, I should be grateful for particulars respecting metals used, cost! Do not refer to back numbers.-W. H. E., Coventry.

153247.]-Paint Blistering.-Is there any preparation or mode of mixing paint to prevent blistering from the heat of the sun, or is this in any way due to the quality of the timber! Suggestions for treating a hall-door for this defect would much oblige.-APRIL FooL.

(53248.]-Battery.-I have three quart Bunsens, previously been used for plating, &c. I wish to convert them into Leclanchés for bell work. Will some kind

reader inform me how to do it, and what solution and quantities to use - ONE IN a Fix.

[53231.1-American Railways.-Have any new American railway engineering 1-QUIDAM. editions or works been published lately on the subject of

[53232.]-Dynamo.-To MR. BOTTONE.-I read in last week's" E. M." that it will not do to run the dyn mo minutes. Will you kindly say if it can be run continuyou are describing continuously for more than twenty ously at a lower rate, and how many volts it would then give? I wish to work it by small windmill, to charge an accumulator having E MF. of seven volts, and it should be capable of running during the whole twenty four hours, or when there is wind. If it won't do for this, how can it

be altered? - Lux.

[53233.]-G.N.R. Locos.-Will any loco. correspondent kind y give dimensions and sketch (if possible) of the new bogie passenger tank engines on this line, No. 694 class, with cabs greatly altered? How many

are there of this class --H. N.

-AIR-PUMP.

[53250.]-Wrought Iron Work.-I wish to turn down some 3in. lengths of wrought iron accurately to in. diameter, but I am rather uncertain as to the best way to set about it, as I fear that, however carefully I back the work up, being so slight, it will spring from the tool. Can any of your readers help me! Would it do if I was to grind them down by means of a revolving the blanks for the twist drills are made. My work must emery wheel fixed in the slide-rest? I fancy this is how be quite true, or it will be of no use.-G. STOCK.

[53251.]-Gut Lathe Band.-Is the making of a gut lathe band within the power of an amateur? I am told they are made from the intestines of sheep. If that is so, will some kind reader please explain how? Raw material is easily obtained, hands are willing, but cash very scarce.-RUSTIC MECHANIC.

desirous of fitting one to my launch, will some one kindly [53252.1-Silencing Tank for Launch. -Being give me particulars of construction of one, or refer me

[53236.1-Portable Forge.-I have made a portable forge and bellows, but cannot get the bellows to fill with sufficient force to gradually lower top side. It will bump down at the same time I raise the lever. The clapper at bottom works all right. My bellows are 2ft. square. Can any kind friend tell me the reason of my difficulty? I should esteem it a favour. TROUBLE.

ONE IN

(53237.-Model Steering Gear.-I shall be glad of a proposal for the above, the action of which shall be automatic, but unquestionably reliable. The desired end for a fixed time, when the rudder shall be acted on until Is that a 5ft. inodel steamer shall steam straight ahead the turn homewards is made, and then, of course, resume its previous position. Would not clockwork be more simple for the purpose? Particulars will be esteemed.— DOUBtful,

[53238.]-Dynamo-To MR. BerTONE.-My armature, 10 by 2, on which is wound 2lb. of 16 wire; on field

Also how to prevent the salts from accumulating on the top of zincs! I clean the zincs every month, and scrape the cells and wipe them with a dry cloth; but they get as bad again in a week or so.-A. J. G.

[53254.]-Lantern-Microscope. I have two oxyhydrogen lanterns, and want to make a microscope attachment to enable me to show small objects. What lenses shall I want (the condensers being 4in. diam. aud in. focus) ? Can I use balsam mounted objects? Will some reader kindly furnish me with a little information on this subject 1-E. H. SHORT.

[53255.]-Carbolic Oil.-I shall feel obliged if some of our chemical contributors will inform me what quantity, in drops, of carbolic acid is added to ether oil or glycerine to make the so-called "carbolic oil" or "carbolic glycerine," both of which are used as outward applications.-CARINO.

department of the Natural History Museum I saw

(53256.] Tourmaline. - In the mineralogical pink variety the same polarising power as the ordinary "Rubellite: a Pink variety of Tourmaline." Has this dark green crystals -i e., would two slices stop a ray of light as much as the dark variety when the axes of the crystals cross each other? What is the difference in composition ?-KANET.