not wine, and if it is "wine" it has undergone fer- articles in the Daily Telegraph which treat upon NUN. DOR. [54295.]-Guttapercha Cement for Leather. Dissolve indiarubber or guttapercha in bisulphide of carbon; but if you are wise buy it ready made. The only "secret" about it is to have the surfaces to be joined thoroughly clean; and with leather, that is best achieved by cutting the surface off with a thin sharp knife.-ARAIWY. 154286.]-Bookworms. I am glad to let "Bibliophile" know all that I know myself about the bookworm. A bundle of quires was being opened at a well-known publisher's the other day (54295.]-Guttapercha Cement for Leather. when it was noticed that the paper was drilled-S. E. Simpson should go to a leather furnisher through, and on separating the sheets three of these and buy one ounce of gutterpercha shavings and an "insects" were discovered stowed away in the ounce and a half of carbon-bi-sulph. Should the tunnel of their own making. They were quick in merchant not keep this last-mentioned in stock, their movemente, of a cream white colour, and the you can get it at any chemist's. Then get a under portion of their body seemed to the naked stoppered bottle large enough to hold it. Stopper eye to be possessed of a number of hair-like legs. must be a good fit for bottle, because the carbon These were all in active motion. The creature's will evaporate. Method of applying it: Skive your head was represented by a reddish brown spot, and patch thin at the edges, also scrape the place where the body slightly thickened towards the tail. I patch goes; use a handy bit-stick, put a coat on should hardly think "maggot" would fairly each, and put both surfaces together immediately, describe the insect. It is entirely different in ap- or you will spoil your job. You should have a last pearance to the ordinary maggot found in decaying in the boot before applying the patch. If you will matter. Besides, I think that maggots, as a rule, take the trouble to advertise your address next eat an irregular hole on the surface, and do not week, I will forward a sample made up for use, bore through a body on which they live. Whether free.-JOHN M. MACKAY. the bookworm lives on the paper through which it travels is a point that does not seem to be settled. The source from which the Daily Telegraph got its information was from the Publisher's Circular, to which I forwarded a paragraph announcing the discovery. I have access to a large number of scientific works, and, as far as I can tell, not one of them mentions the bookworm. I judge myself that the worms work with great speed. I am led to this conclusion by the vast amount of work they get through. It has been known for one worm to travel through several yards of books, binding and all. [54304.]-Lathe Mandrel.-Every maker has his own ideas upon this vexata quæstio, and any one who attempts to answer this query may look out for the critical cuts of the front-saddled animalcula. My view of the matter is that a small amount of taper is the best form, as its being so is only for the purpose of taking up the wear. You omit to state the diameter of your mandrel; but I would suggest that the length of the collar, or bearing, be not less than the diameter of same.A., Liverpool. I [54306.-Dynamo. - To MR. BOTTONE. should connect the other eight lamps, place the brushes at the normal position, and note the heating. If I found that the heat was too great, I should arrange the lamps in a combination of series and parallel, so as to get approximately the resistance required.-S. BOTTONE. At the rate of eating or working adopted by the ordinary maggot, it would take many years to penetrate this distance-longer than any insect is known to live. It is astonishing to one who inquires to find the absolute ignorance of the bookworm's life. I feel sure that any further particulars of the worm, &c., would be of great interest to many of "ours." I believe that Mr. Blades, in [54311.]-Arc Lamps.-To MR. S. R. BOTTONE. his Enemies of Book," devotes some space to-Size of carbon, fin. diameter, 8in. long for upper the bookworm; but, unfortunately, I do not, as I carbon; 4in. for the lower; the upper being +. I should like to, possess a copy. Perhaps Mr. Blades believe there would be uo infringement, it being will give us a few words himself on the subject.- a modification of Browning's and Lever's. The A. J. BOWDEN, JUN. Siemen's H-girder armature is an expired patent.S. BOTT NE. [54287.]-Pacinotti Dynamo.-The field magnets retain sufficient magnetism to start the machine. -S. BOTTONE. [54315.]-Lifebuoy. - Procure some good strong canvas, and sew it up into the usual ring form, and fill up with old corks from the pubs, if procurable. Failing this, purchase the necessary corkwood from a corkcutter; give it several coats of white lead paint, and float it as a going concern. [54290.]-Pure Water.-Pure water means of course potable water, that is, sufficiently wholesome to drink, for absolutely pure water cannot be kept for any length of time, as it will dissolve even glass. The querist should boil the water and then pass it-A., Liverpool. through the filter recently described by Professor Guthrie in these columns-the penny filter I think he called it, which is much better than some of the expensive contrivances sold as "filters" (save the mark!). To get pure water it must be distilled, and even then it cannot be kept pure. The statements about the 20,000th part of alcohol preventing the growth of this and that are, in connection with pure water, simply nonsense, no matter who stands sponsor for them.-S. R. [54315.]-Lifebuoy.-A wooden hoop with half a dozen inflated bullocks' bladders attached for immediate use; for future and permanent use collect all the old corks come-atable, fill calico bags therewith, and attach in lieu of bladders. A few loops of line pendant from hoop and there you are. A faggot of rushes would do at a pinch.-C. Portland cement do the biz. ?-A., Liverpool. [54316.]-Slate Water Cisterns.-Why won't [54291.] - Unfermented Wine. The fruit H. R.," shellac dissolved in naphtha or patent [54316.]-Slate Water Cisterns. In reply to must be brought to the state of a preserve (some-knotting worked into the crack when the slate is thing like apple jelly or currant jelly) by evaporation, preferably in a vacuum pan. The inspissated juice can be added to water as required. The addition of a small percentage of salicylic acid will prevent fermentation in saccharine fluids; but I believe this addition is not agreeable to law. - S. BOTTONE. ས B K R E [54291.1-Unfermented Wine.-I was thinking of sending a similar query to that of "Althaus,' as some slight check on the stupid remarks of the oneidea men who have recently aired their crotchets in the "E. M." If there is such a thing as unfermented wine-if there ever has been anything of the kind-by all means let us have the facts-not quasi-learned disputations about "tirosh" and yayin," concerning which the writers know as much, I suspect, as the "man at the corner." I am afraid that those who drag the Bible into the discussion have not much respect for that wonder. ful book, and at any rate I think that the question being one of fact can be settled on the hard and fast lines without any appeal to the "sentimental" aspect of the question. There is no such thing as perfectly dry, or even some good stiff red lead, will "uufermented wine." The terms themselves are often stop leakages in slate cisterns; but it must be contradictory, for if a liquid is unfermented it is remembered that the cistern must be perfectly dry Slate Side Bottom Fig.1 before either of the above materials is applied. The material must also be allowed to get thoroughly dry or set before the water is turned into the cistern. Should the cistern be too far gone, or the crack too large, it may be necessary for you to use a plate, which may be put on as follows (see AB, Fig. 1): -Take a piece of slate, or even iron, as shown at B, having holes bored as at the dots; place this plate over the crack as shown at B A, and mark the holes on the slate, which may be afterwards bored with a brace and drill; after which paint all over the back of the plate B and the slate side where the patch is intended to go, then with some red-lead putty bed the patch B firmly down, and screw it in its place with some small bolts. If the crack is too large for this job, unscrew the nuts HG, &c., and put in a new end, side, or whatever it may be.-P. J. DAVIES. [54319.)-Harmonium.-The defect is probably caused by the reeds not being properly set. Each tongue should be a trifle above the block at its free end. Probably some of the vibrators are too high above the block, while others may not be high enough, or the defect may arise from other causes ascertainable only by a personal inspection of the harmonium in question.-G. FRYER. [54319.]-Harmonium.-Without pretending to understand what "All Together" means by the "voicing" of his harmonium reds being "all right," I may tell him that the de ect of which he complans is due entirely to the reeds not being set right. It is not likely that they are voiced, in the ordinary meaning of that term, and all he can do is to lift or depress them until they do speak promptly: he must not bend or straighten them. Harmonium reeds are not "voiced," as a rule, and they ought to speak promptly, or else hold their tongues. The querist seems satisfied with the tone, and the unevenness of speech is to be remedied by setting the reeds. That is to be done with a little patience by gently lifting the vibrator or depressing it, until the best effect is obtained.-S. MAYER. [54322.]-Zinc Cisterns.-In the country these cisterns are often lined by the plumber, and therefore I shall give my reader an insight how to proceed with this work. First, cut your metal in such a manner that the soldering is always away from the angles. Now examine Fig. 337 suppose the sheet CD EF there shown to be the size of the end or side of a square cistern-call it 2ft. 6in. long and 2ft. 6in. deep; first strike the bottom line AB, then measure off 6iu., as from E to L, or K to C; this return edge is to allow the zinc to be soldered up without being soldered in the angle, and as shown at FAEN, Fig. 96. Draw the line EF, measure the metal as at CE, FD; then take the now measure the end or side of the cistern, and bevel set to an angle of 45°, and lay it upon the bottom line AF, and with a pencil mark the lines BH, FI, DJ, AG, and with the snips cut out the scollop pieces, JGA and IHF, but leave about lin., as at RQ, to form a kind of underlap when the zinc is bent round. Of course, if the cistern 18 not square, the piece HLF, &c., must be cut out accordingly, which you easily tell by practice. Now get a piece of quartering, say 4in. by 3in., and lay it on the line DF, then pull up the bottom, GIJH, square to the quartering, and with a zinc worker's mallet (viz., a boxwood mallet with a flat head), knock the zinc square up to the quartering; next lay the quartering on the line FM, and bend the side or return zinc, LB. up to the quartering as before. Serve the other side likewise, and the end or side of the cistern is ready to put in (should you require an inch or so to turn over the top, allow for this when measuring the depth; it is usually done). The zinc is now bent to the shape shown at Fig. 338, also as shown at Fig. 324. Now measure ail your cistern, and line it as directed. When all is marked, cut, and bent up, put it in, and with a few zinc or other nails, nail it; put the bottom in so as to be able to solder it, say from 3 to from th angle, knock the corners as at F and D, so that they are a little rounded and so that they will not catch in the angle or sides when you are sliding or dropping the metal into the cistern. Soldering a Zinc Cistern.-Suppose your cistern to be a fixed one, and to be lined as at Fig. 96. First solder up the upright seam, A F, which is done as follows: having your copper bit nice and clean, with a pointed nose and with a face all round, with a spirit brush put some raw spirits of salts all up the joint intended to be soldered. Now have a stick of good, fine solder, and begin at the bottom at F, Fig. 96. First put the solder against the seam, and with the bit bite a bead of solder off, which will still hang to the nose of the bit, and transfer it to the zinc; then another bit of solder, and transfer this just above the last bit, and so on, bit by bit, until you get to the top, doing about in. to in. at each time until you can do larger pieces. Of course, you should bite the bit of solder off the stick when the solder is held up to or against the seam. The secret of this soldering work lies in being able to transfer the solder from the stick to the zinc in such a manner that it will appear like that shown at F A, Fig. 96, which will soon be acquired by patience and practice. After you have run up your upright seam do the bottom, which will be easily understood after what I have written on soilpipe soldering, &c. Always solder your work strong, and be sure to see that every bit of your joint is properly tinned and covered with solder. Always wipe the joint with rag and water after the soldering is done: this is to take off all traces of the spirits of salts.-P. J. DAVIES. 53833. Angle Irons, 288. 54009. Tin Metallurgy, p. 39). 51016. Displacing Yellow Prussiate of Potash, 350. 54041. Electro Motor, 381. 54042. Tile Burning, 381. 54051. Welsh Smokeless Coal, 381. 54056. Boiler Query, 381. QUERIES. [54323.]-Wind Engines.-Will any of your correspondents who have experience in wind engines to raise water, give your readers the benefit of it and say which is the best description -J. G. S. [54324.]-Pulverised Ozone.-What is pulverised ozone? I read in the Lancet that Dr. Onimus has gone to Marseilles to study the epidemic, and to try the administration of pulverised ozone. Does that mean atomised ozonised water, or what?-DOUBTFUL. [54325.]-Indian-Ink Stains.-By what means can Indian ink stains be removed from cotton and linen? -DRAUGHTSMAN. [54326.]-Dividing Circles.-Would "W. H. B." kindly give fully the geometrical method referred to by him in 54818, p. 473?-J. J. E. [54327.]-Condenser for Coil-I have made a coil, core 7in. long, two layers No. 18 for primary, and 15 layers No. 40 for secondary, with pint bich. I get a Will some spark nearly in. long without condenser. gentleman kindly inform me what quantity of tinfoil, 10 by 6, I will require to get best results! Also, what length of sparks I may expect when complete!-Pro GRESS. reader tell me how and where I could obtain a private [51328.]-Propeller for Steamer.-Will some lesson as to the mode of striking out a propeller for a steamer? I am a pattern-maker by trade, and am anxious to have some instruction concerning the above problem. Further, I should like to know what should be the charge for the same, as I should wish to have it sent by post to me.-XANTIPPE. [54329.]-Beta Cygni-Having split Beta Cygni with 54 0.g., power 66, I am desirous of knowing whether the above is considered a fair test object. The instrument is a dialyte.-A. BEST. I have Temperature in Deep Mines.-At a recent meeting of the American Society of Civil Engineers reports upon the temperatures of the earth as shown by deep mines, were presented by Messrs. [54330.]-Sweating Screws.-I shall feel oblized Hamilton Smith, jun., and Edward B. Dorsey. At if any of your correspondents can enlighten me on the the new Almaden quicksilver mine at California, above subject. I have to make a screwed joint tight and at a depth of about 600ft., the temperature was tested to 300lb. per square inch according to specifications very high-some 115-but in the deepest part of by sweating, say, for example, 6in. tube and socket. I the same mine, 1,800ft. below the surface and have first to screw the tube and socket a little easy to allow for a coating of tinning, then it has to go to the 500ft. below sea level, the temperature is very coppersmith or tinplate worker to have the screws pleasant, probably less than 80°. At the Eureka tinned; then I have to screw them together, moderately mines in California, the air 1,200ft. below the sur-tight, when it again goes to the tinplate worker to be face appears nearly as cool as 100ft. below the sweated, which is a secret process of the trade.-PERsurface. Mr. E. B. Dorsey said that the the mines PLEXED. on the Comstock vein, Nevada, were exceptionally hot. At depths of 1,500ft. to 2,000ft., the thermometer placed in a fresh-drilled hole will show 130. Very large bodies of water have run for years at 155, and smaller bodies at 170. The temperature of the air is kept down to 110', by forcing in fresh air cooled over ice. Captain Wheeler, United States Engineers, estimated the heat extracted annually from the Comstock, by means of the water pumped out and cold air forced in, as equal to that generated by the combustion of 55,560 tons of anthracite coal or 97,700 cords of wood. Observations were then given upon tem- [54332.]-Orickets.-What can I do to drive the perature at every 100ft. in the Forman shaft of the crickets away from my fireside! I don't want to kill Overman mine, running from 53' at a depth of them-innocent creatures-but they are a nuisance, and 100ft. to 121-2 at a depth of 2,300ft. The temno mistake. Will some one help me ?-ABAIWY. perature increased:-100ft. to 1,000ft. deep, in[54333.1-Securities for Friendly Society.-Is crease 1 in 29ft.; 100ft. to 1,800ft. deep, increase there any means of safely getting more than three per cent. 1 in 30 5ft.: 100ft. to 2,300ft. deep, increase 1° in for the spare funds of a friendly society? The rate of in32-3ft. A table was presented giving the tempera-terest is a measure of the security, I know; but is there tures of a large number of deep mines, tunnels, any safe investment which yields more than three per and artesian wells. The two coolest mines or tunnels are in limestone, namely, Chanarcillo mines and Mont Cenis tunnel, and the two hottest are in trachyte and the coal measures," viz., the Comstock mines in trachyte and the South Balgray in the coal measures." Mr. Dorsey considered that experience showed that limestone was the coolest formation. Lathes and Lathe Fittings. We have the [54331.]-Galvanic Belts for Cramp.-I suffer very much at night, sometimes, from severe cramps in my legs, and have to get up and walk about the room for half an hour at a time, to get rid of them. tried black silk, and also flannel, in strips tied round each leg below the knee, like garters, but still I am subject to this affliction. My daughter also is troubled in the same manner. I shall be much obliged if any of "ours" can suggest a remedy, for I know of none. Perhaps Mr. Sprague, Mr. Lancaster, or other electrician, will kindly give this their attention, and say, whether or not, any kind of galvanic belt or garter, would be likely to prevent the cramp? A reply in "ours" will greatly oblige.-LD. W., Taipeng-Perak, via Penang. cent. 1-NEMO. [54334.]-Verdigris Battery-I see a notice of verdigris being used as a much cheaper material than construction of the cell and its E.M.F. 1-B. F. oxide of copper. Can any correspondent kindly state the [54335.]-Engine for Dynamo.-To Ma. W. H. E., COVENTRY. I have a well-made engine, 3in. diameter and iin. stroke, cutting-off at stroke, steam-pressure Soib. per square inch, revolutions, say, 750, and dynamo tough to rure dynamo described by Mr. S. Bottone in 1,500 per minute. Would such an engine be powerful new catalogue of the Britannia Company, Col-No. 10! My boiler will make steam for an engine chester, which contains, besides the usual matters, twice the size.-AH SING. some new features in the shape of price lists of parts, castings, &c., which will be useful to many of our readers. [54336.]-Turret Clock Striking.-It is desired to cause the time of each hour to be sounded on a large turret bell. The cost of a turret clock cannot be afforded. Is it possible, by electricity, to make a small eight-day clock, at a little distance, strike the hours! If so, what striking gear would be required, and what electric connections made? Is there any treatise hereon ?-H. R. [54337.1-To Mr. Lancaster.-In your reply, No. mend bronzing the latter in arg. nitr. and then black54250, on retoning solution and diaphragms, you recom leading them. How long are they to remain in the silver solution should they be put in hot? And will blackfresh from the optician's hands? I have tried and failed. leading them give the dead black that we find on them as J. C. BROWNE, D.D. 154338.)-Trains.-There is an express which leaves King's Cross at 10 a.m., and runs to Grantham, arriving at 12.10. I wish to know the dimensions of the engines which usually take this train, the average weight of the train, the amount of coal consumed, and of water evaporated during the run.-W. Jонм GREY, F.C.S., Shotley Bridge. [54339.]-G.N.R. Locos.-Wanted, dates of following:-1, 33, 34, 47, 83, 548, 550, 667. Are 669 and 670 8ft. singles? Wanted, also, engines stationed at Retford and York (G.N.R.)—DUBLIN. [54340.]-Preserving Trout.-What is the best way to keep trout fresh for two or three days?-and how should they be packed at a remote Scotch angling lake 1-KEEL. [54341.]-Quartz Eyepiece.-What is Hilger's quartz eyepiece, referred to by Mr. Rand Capron, letter 18147, Dec. 3, 1880 ?-E. HOLMES. [54342.]-Bichromate Photos.-It is well known that when pa per is coated with a solution of bichromate of potash it darkens in colour on exposure to the light. What precise chemical change does it undergo? Is there any substance by which the darkness may be intensified, so that a copy of a photograph may be taken and toned to a suitable colour by this process !-PE. GE. [54343.)-Repairing Patent Leather.-Can any of your readers inform me the components of the material used on patent leather Cavalry boots, and if it is possible to apply it by heat, or otherwise, where the leather has been cut, and the varnish destroyed by the rowels of spurs ?-LT. COLONEL. [54344.]-Watch Pivoting.-Will some watchmaker kindly answer the following?-Is a lathe a better ing before being drilled? What speed is the best for tool than turns for pivoting! Does a pinion want softendrilling, and which is the best way to harden drill for the above work?-COUNTRY. [54345.]-Syrups -Will any reader tell how I can make syrups or flavouring for making ginger ale, and other similar drinks! I have a gazogene; I can, there fore, produce the aerated water. Is there any book on the subject 1-H. G. [54346.1-Warbles.-Can any of our horsey readers tell me how to prevent or cure warbles in horses! H. G. [54347.1-Great Circles.-Will your correspondent, "E. L. W. H. S.," p. 487, kindly favour the readers of the "E. M." with the method by which the radii and distance of the two wheels are calculated —A. GEARING. [54348.1-Piano Repairing.-Some time ago I was advised to put new leathers on a portion of my piano immediately over the keys, as the old was worn through; but I find it is rather too thick, and am told I must cut off the tops of the hoppers. Can any reader inform me if that is correct, and how I can get them smooth and polished as they are now -TYRO. [54349.]-Medicinal Cod-Liver Oil.-I would like to start the manufacture of cod-liver oil for medicinal purposes. Can any reader give any useful information? Also, what the probable cost of small machine, together with all necessary article for a small commercial enterprise! Please give full details.-COD. [54350.]-Oyster Room.-I have a room 20ft, by 12ft. behind shop which I wish to fit up as an oysterroom: Will any reader give particulars how I may best furnish and equip as a plain and respectable oyster-room at small cost!-FISHMONGER. [54351.]-Intense Cold.-I have a cellar in which I wish to create and maintain the most intense cold pos sible. Can any reader advise me how I may accomplish such an object? I'remember when a boy a party show ing me how to freeze a tin can to a board of wood along side of a fire. I forget how it was done, but salt, I think, was one article used. Any hints will be thankfully received.-ZERO. [54352.]-Arcs of Large Radius.-I would very much like to be able to do this correctly. I have measured B D (letter 23043) at five places from A, taking a radius of 5in., and I cannot work either the method of "J. M." or "A. S. L." (23092), so as to agree with the actual measurements.-OLD BLOW-HARD. [54353]-Gilding on Glass.-Can any of your numerous readers tell me how to make up a good size or vehicle for gilding on glass? I have tried several ways which I believe are used by glass writers and burnishers, but I cannot get my work satisfactory, which looks misty, streaky, and each joint of the gold leaf shewing to A little information upon the a very unsightly extent. subject as to the manipulative process would be esteemed a great kindness.-SIGN WRITER. [54354.]-Segments of Circles.-Will some corre spondent kindly inform me if the following method is correct? I want to make a wooden wheel 24. diameter in six pieces, and to have six spokes, and each piece to form the circle to be 2in. in depth. Suppose I take a strip of wood 12 in. long, 4in. broad, in, thick, fara pattern, should I draw a line through the centre and open the compasses to 12in., and strike the circle, and again with the compasses to the extent of 10in., and then from the line and on each circle, to get the propez angie !— the centre line take in the chord of 30° each side of A. LESTER. [54355]-Thread Weather Guide-Will some reader kindly tell me what substance in the form of thread is most sensitive to the effects of moist and dry airs, that is, expands and contracts most.-L. C. [54336.1-Crab for Lifting-Will someone give me instructions about crab to lift 25 to 40 tons; whether the frame should be made of wrought iron or not, and I would like it to be treble-gear motion? Will someone give me a diagram of same, and give me instructions how to gear it, and what should be the pitch of teeth of wheels for treble gear, and a description of frame?-J. M., Cumberland. [54357.]-Voss Machine.-Would "Sigma" or some other gentleman kindly tell me why my recentlymade machine fails! It has been very carefully constructed, and the Leyden jars are made of best tubes 6in. by in. Is it in the fault of the latter? The machine contains plenty of electricity when at work, but I can only get a fin. spark from the conductors.-By STANDER. [54358.] The Clay Telephone. Would any brother reader give me the details of the Clay transmitter so as to enable an amateur to make one? The details of the receiver are fairly given in the last number of the Electrical Review; but it would be impossible to construct a transmitter from the information given therein. What size wire should be wound on the poles of the magnets to get the best results ?-T. W. C. 154359.]-Percolator.-I have a coffee pot from which the tin or amalgam has worn off. It is well made and strong, but in its present state looks very unsightly. I am told that the cost of having it retinned would be almost as great as that of buying a new article. Will someone please say if I could paint or Japan it without much difficulty, so as not to spoil it, or if I could affect its outward appearance in any other way in order to make it a little more presentable ?-E. E. H. ANSWERS TO CORRESPONDENTS. All communications should be addressed to the EDITOR of the ENGLISH MECHANIC, 31, Tavistock-street, Covent arden, W.U. HINTS TO CORRESPONDENTS. 1. Write on one side of the paper only, and put drawings for illustrations on separate pieces of paper. 2. Put titles to queries, and when answering queries put the numbers as well as the titles of the queries to which the replies refer. 3. No charge is made for inserting letters, queries, or replies. 4. Letters or queries asking for adfresses of manufacturers or correspondents, or where tools or other articles can be purchased, or replies giving such information, cannot be inserted except as advertisements. 5. No question asking for educational or scientific information is answered through the post. 6. Letters sent to correspondents, under cover to the Editor, are not forwarded, and the names of correspondents are not given to inquirers. Attention is especially drawn to hint No. 4. The space devoted to letters, queries, and replies is meant for the general good, and it is not fair to occupy it with questions such as are indicated above, which are only of individual interest, and which, if not advertisements in themselves, lead to replies which are. The "Sixpenny Sale Column" offers a cheap means of obtaining such information, and we trust our readers will avail themselves of it. The following are the initials, &c., of letters to hand up to Wednesday evening, Aug. 6, and unacknowledged elsewhere: P. [54360.]-Dynamo.-I have made a small dynamo, and I have wound it with 91b. of 16 D cotton-covered CT. wire. 1lb. on the armature, and 74lb. on F.M. It is 10in. by 2in., and pole pieces bored out to 2 5-16in., and I can melt from 6 to Sin. of 30 iron wire at 1:500 revs. per minute; but when I put a 20 c.p. Swan lamp in the circuit, I can only just make it red hot. The lamp is one of Swan's D 120 c.p.1., and marked in catalogue, E.M.F., 46 volts; current ampéres 1:32. Would either Mr. Bottone or W. H. E., Coventry," state in "ours the cause of my failure and the remedy for such, as it will, perhaps, interest others as well. The machine is joined up as shunt, and I drive it with foot lathe; but when lamp is in circuit there is such drag on it that I can only make 1,000 revs. with all my strength.-MORE LIGHT. [54361.)-Legal.-In a county court action defendants are described as executors do son tort. What is the meaning of the Latin phrase?-0. (54362.1-Direct Coupling of Cranks.-I shall be obliged if any reader of "ours" will inform me of the best way to couple a 9in. crank direct with a 6in. onegiving sketch if possible-so that they may make the same number of revolutions in a given time.-THOS. H. HALE. [54363.1-Challow Accident.-To MR. STRETTON. --Can Mr. Stretton kindly give any particulars of this accident which happened about Jude last? The engine drawing the 10.20 or 11.25 p.m. train at Padd, broke its connecting rod whilst running at a high speed, and, according to the newspaper report, "the brake brought the train to a stand within the space of a few yards."T. M. R. [54364.]-Carlton's Ejector.-Can any of "ours" give an account of this noiseless ejector which is used on the L. and Y.R. I understand that the G. W. engines lately fitted with the apparatus for creating a vacuum employ a modification of this patent.-T. M. R. [54365.]-N.B. Locos.-Would any correspondent kindly inform me whether any locos. of the undernoted classes are described and illustrated in the Engineer or Engineering:-4-coupled bogie Waverley, 7ft. single driver, Glasgow, and the 6-coupled goods engines, al designed by Mr. Drummond? Please give dates and numbers of the papers, so that I can get them.-T. G. T. 154366.1-Legal. A kind word of advice in the following cases would be thankfully accepted. A. in effect agrees to purchase the equity of redemption of a house of B. At the settlement, payment is demanded from A. by the mortgagee's solicitor of his bill of charges. The mortgage being paid off at same time. The solicitor's account is worded as a charge against the mortgage, but A. is expected to and does pay it. Should he have refused? Is it now beyond correction if wrong! Can the bill (now paid) be taxed? In connection with the above, one question more occurs. Can a board of management of a Starr-rowkett Building Club legally pass a resolution that the club's solicitor shall have half as much again as his regular fees in a case where two appropriations are lumped on one property? Would this stand the taxing test?-C. O. [54367.]-Extraction of Silver from Lead.Wild some of your correspondents kindly inform me in the "E. M." can the above be done on small scale and reasonable profit. There is plenty of ore here from foreign parts; what the plant or furnace may cost? I am told there is some rather late process.-O., Liverpool. Ginger Champagne.-This refreshing and agreeable beverage is, according to a French recipe, made as follows:-Take 60 gals. of water; add 40lb. of ginger cut in small pieces, and gently boil for half an hour, carefully removing any froth that may arise. Cool the liquor as quickly as possible, and when at a blood-heat (100° F.) add 91b. of raisins chopped fine and the juice of 6 doz. oranges and 6 doz. lemons. Allow the liquid to ferment, and after standing a month it may be bottled in the usual manner. If desired, the ginger may be omitted, and the number of oranges increased to 18 doz. M. R.-J. and H. Grace.-O., Liverpool.-John M. Mackay.-B. Martin.-Circumscribe.-E. Miller.-W. Gooda re.-W. Binns.-T. H. Hale.-A. Best.-0.— Glatton.--C. O.-T. G. G.-William Grey.-Science Student.-S. Bottone.-Dr. Edmunds.-C. "Coppinger, F.R.C.S. NATURE. WARD. (Please remember that engravings take a little time," and that we must have drawings by Saturday at the latest to appear in next number.) JOHN LUKIN, (With the spark, of course; but it is tedious compared with the machine.)--Luc. (Depends entirely on the terms of the will. Better consult a solicitor.)-PHONO. (They are simply ordinary electric bells, such as have been described many times. See p. 586, Vol. XXXVI., for instance. Which battery they are worked by depends on circumstances; but what a relay has to do with it is a puzzle.)-Lusus (Is it of any interest to the one-millionth part of our readers?)-VERAX. (Thank you.)--OMICRON. (See some replies in back volumes. You can dissolve it off with turpentine or naphtha, but it will inevitably leave a stain. You can reduce that to a minimum by again washing with turps or benzoline and applying a warm flat iron over blotting paper. 2. Lockwood and Co. publish a book which may suit, Get their catalogue.)-ODOUS. (No. Wash it, allow it to settle, and then dry the precipitate.)-BOYEVRUS. (An ordinary middle-class education, and practice in field work, that is all. See the indices.)-J. W. W (It is a question for experiment; but we should think a small gas engine would be more efficient and more practical.)-JULIA, (For removing stains from cotton and linen, see p. 454, Vol. XXXVII. As a rule, exposure to the fumes of burning sulphur will remove those you refer to.)-TOBIAS. (You will find some hints on the subject in back volumes; but the rules can be easily devised, surely.)-EMRYS. (Shellac cement ought to do; but the cement you have tried is better, only you must have all parts warm. Mastic will also unite bone and ivory. If none of those will do, you might try a mixture of equal parts of anhydrous phosphoric acid and pure caustic lime, mixed and applied as rapidly as possible. Support the parts in position until it hardens)-W. G. W. (It is simply a box with strings on answered by saying there is no such paste, and the third was answered so recently as p. 428, first "answer.")-G. GENDER. (See Dr. Edmunds's remarks about Acne on p. 543, Vol. XXXIV. 2. Your condition that the condenser is to be portable, and yet work for two hours with one filling, spoils the question. It is impossible. You must have a current of cold water flowing through.)-STUDENT. (You can obtain all particulars on application to the director, Mr. P. Magnus, Gresham College, E.C.) E. BEAUSIRE. (Recipes for making whole-meal and brown bread have been given. See pp. 260, 306, this volume. It is the general complaint that it is doughy, and the price is ruled by the demand.)-CHIPF. (The recipe has been given several times. The bronze powder of the desired hue is mixed with a specially prepared varnish-.e., good copal treated with quicklime and. thinned with large quantities of turpentine. Gold size is used only for the rough work, where the powder is dusted on.)-A FELLOW WORKMAN. (See previous answer. These bronzes are known specifically as Bes semer paint.)-H. F. LEWIS. (Lockwood and Co., Stationers' Hall-court, EC., publish at least four books of the kind. See their list.)-LANDLORD AND TENANT. (If there is no stamped agreement, the law says you are a yearly tenant, liable to give six months' notice, terminating at the same quarter as you took possession. Where the tenancy commences between quarter days, that next following the date of actual possession is taken as the commencement of the tenancy. All agreements, notices, &c., should be in writing. As things are, you must make the best arrangement you can with your landlord.) USEFUL AND SCIENTIFIC NOTES. Cyclists and the Repair of Main Roads.On Tuesday, at the Hales Owen Police-court, before Messrs. F. D. Lea Smith and E. B. Phillips, a case of considerable interest to cyclists was heard. The surveyors of the highways for the parishes of Warley, Ridgacre-hill, Hales Owen, and Hasbury were summoned by Mr. A. L. J. Brown, Edgbastonroad, Birmingham, for neglecting to keep the main roads in a proper state of repair. Mr. Deakin (of the firm of Messrs. Tyndall, Tyndall, and Deakin), Birmingham, appeared to prosecute, and Mr. Homfray, of Hales Owen, defended. Mr. Deakin explained that this was the commencement of a crusade which two powerful associations, known as the National Cyclists' Union and the Midland Road Fund, had determined to commence against the Counties. These two associations, with Lord Bury surveyors in charge of the roads in the Midland at their head, numbered over 20,000 members, and represented a body of cyclists who were to-day traversing the roads in this country in all directions. The movement was inaugurated at a mass meeting in Birmingham, and the Corporation of Birmingham had entered into the spirit of the movement and had evidenced their approval of it by appointing a special surveyor, and were taking steps for the improvement of their roads. They did not complain so much of the gentlemen brought before the Bench on this occasion as the system under which they were expected to work. They did not clamour for an increased expenditure upon the roads, but simply wished the surveyors to adopt such a system as would reduce the expenditure whilst it put the roads into a thorough state of repair. Mr. Vincent, surveyor, of Warley Wigorn, was put into the box, and admitted that the main road in that parish was in such a condition that the county authorities refused to allow anything towards its maintenance, and that the road was in such a state in 1881 that the county authorities spent on it £410 per mile in reestablishing it. Mr. Macdonald, of Ridgacre, was also examined, and it was elicited that the main road in that parish was also in an unsatisfactory condition. Mr. Codrington, C.E., presented a lengthy report on the roads, and also gave their condition, which He did not think considered decidedly bad. it was possible to maintain the roads in a thorough state of repair economically under the present system of appointing surveyors of highways for the separate townships, and strongly recommended the formation of a highway district. He had no hesitation in saying that half the money spent on the roads in these parishes ought to keep them in first-rate order. Evidence was given showing that the roads in Hasbury Hill and Hales Owen parishes were in a fairly satisfactory condition, and it was decided to withdraw the summonses against the surveyors of those parishes, and the others were adjourned to allow the surveyors of the other townships time to improve the roads. stretched over it. See p. 497.)-MUSICAL. (The letters "American Organ Making" appeared in Vol. XXVI., but the numbers are out of print and the volume is, too.)-SANITAS. (See the indices for descriptions of various accumulators. How are you going to charge it? If by a battery, don't you think you might as well use the battery direct! 2. What do you want to insulate the copper strips for ?)-A. B. C. (We should think B. ought to apply to the local sanitary authority, and so compel C to put an end to the abomination.)-EMIGRANT. There are several works by Scott Burn, published by Crosby Lockwood and Co. See their catalogue.)-VALVE TUNES. (What a pity you evidence as to did not sign yourself "Constant Reader"! Actually, Mr. Wenham is now describing a better method than one given a short time back. See p. 474, last volume.) -G. W. NICOLLS, Pernambuco. (They can be obtained from the assistant secretary, at the rooms of the Society, Burlington House. 2. None that we know of. 3. There are objections, and as a matter of fact, for all places at which they are suitable they are in time. 4. You can join in the ordinary way by getting a Fellow to propose you; but you would derive no benefit beyond receiving copies of the publications.)-N. P. BLACK. (Try Indian ink. We know of nothing else that will answer all your requirements.)-PLUNGER. Get the catalogues of Spon, Charing-cross, and Lockwood and Co., Stationers' Hall court, E.C. 2. Of no interest to our readers.)-A. B. C., Clapham. (See the indices, or give some idea of what you want to do. We know of no water-blower" of the kind indicated by your query.)-SAM. BUTLER. (We sympathise with you. You are justified in complaining about the persistent misquoting of your line, "He that complies against his will"; but the misquotation is in some sense a guide to the value of other statements, and so it serves a useful purpose. )-W. F. D. RYLE. (See the catalogues of Lockwood and Co, and Spon.)-J. P. H. (You have omitted the information required. Lawyers have nothing to do of necessity with patents. You can take one out yourself.)-W. HILL. (There is no safeguard against such a fraud except the integrity of the agent.)-A SUFFERER. (They are not "drawn " by electricity. It is used to dull sensation when extracting.)-Cryo. (See the indices. The first question is answered by many recipes. The second may be he more or To prevent the cracking of the glass tubes that are connected with steam boilers to show the height of the water within, and which is of a less frequent occurrence, as the tube is of a high temperature inside, and a cold current can strike them from the outside, the Industrie Blatter recommends the use of two glass tubes, one within the other. The air that is confined between the two serves as a protection to the inner tube against outside cold, and the outer one against the high temperature of the inner one. Both tubes are packed in the same brass couplings. New Electric Batteries.-A novel thermochemical battery has been invented by M. Vincent Riatti, professor in the Polytechnic School at Torli (Italy). The production of the current results from the difference of temperature of two layers or strata lying at different levels in a vessel filled with liquid. The cell consists of a wooden box or vessel traversed by two copper pipes placed the one over the other, and separated by about half the height of the a distance equal which is filled with a solution of sulphate of vessel, copper. A current of steam passes through the upper tube, and a current of cold water in the lower, with the effect that copper is deposited on the latter, while the substance of the former is reduced. By changing, from time to time, the position of the tubes, equilibrium is established. the 18th of August. This battery is said to work well and not to polarise, but up to the present no practical information as to its performance has been published, and consequently we cannot do more than call attention to the principle of its action. M. Grimfeld, of Vienna, has devised a modification of the Callaud battery, in which there is employed a glass vase divided in two by a mid partition half the height of the vase. The two upper halves are thus in free communication, while the two lower halves are separated by the partition. In the bottom of one of the cells is placed the disc of copper; the zinc is at the top of the other. By this arrangement the deposition on the copper of black particles falling from the zinc is avoided; at the same time, however, the resistance of the cell is increased and its cost augmented. A modification of the Leclanché element has received from its author, M. Fein, of Stuttgard, the name "immersion battery." It cousists of a glass vase, at the bottom of which is placed a layer of binoxide of manganese. The vase is closed by a cover carrying a carbon and a ring of zinc. An inverted flask filled with a solution of chloride of ammonium keeps up the supply of liquid.-Engineering. Every Workman connected with the Building Trades requiring a Situation should advertise in "THE BUILD ING NEWS," published every FRIDAY, price Fourpence, at 31, Tavistock-street, Covent-garden, London, W.C. senting Architects and Builders, and has the largest circulatie "THE BUILDING NEWS" is the Principal Journal, repre of any Professional Journal in the kingdom. Every Workman should insist on seeing "THE BUILDING NEWS" every week at his Club or Coffee House. He will fad more "Lists of Tenders" for new work in it every week than in munication" if he wants to know anything about his trade, o any similar paper, and can thus judge where work is likely to be had. He is also specially invited to make use of "Intercomwrite to the Editor if he has any suggestions to make, and to advertise in the paper when he wants work. for Twenty-four Words, and Sixpence for every Eight Words after The charge for Advertisements for Situations is One Shilling 5s. 6d. for Six Months and 11s. for Twelve Months, Post-tree s tndles, Canada, Nova Scotia, Natal, or any of the Australian any part of the United Kingdom. For the United States, 13, or 3 quis. 25c. gold; to France or Belgium, 138., or 16f. 30c.; to India Colonies, 13s. via Brindisi), 158. 2d. to New Zealand, the Cape, the West ordinary newspaper post, but must be remitted for at the rate of The remittance should be made by Post-once order. Back aumbers cannot be sent out of the United Kingdom by the 41. each to cover extra postage. Messrs. JAMES W. QUEEN and Co., of 924, Chestnut-street, Phila delphia, are authorised to receive subscriptions for the United states for the ENGLISH MECHANIC, at the rate of 3 dals 15c. gold, or Thirteen Shillings per annum, post-free. The capi issued after the receipt of the subscription. If back numbers are will be forwarded direct by mail from the publishing office in London. All subscriptions will commence with the number first required to complete volumes, they must be paid for at the rate of 4d. each copy, to cover extra postage. Vels. XXIV., XXVII., XXVIII., XXX., XXXII., XXXIII. XXXIV., XXXV., XXXVI., XXXVII.. and XXXVIIL would do well to order volumes as soon as possible after the conbound in cloth, 7s. each. Post free, 78. 94. All the other bound volumes are out of print. Subscribers clusion of each half-yearly volume in February and August, a post-free, 3d.) print. Most of our back numbers can be had singly, price 34. only a limited number are bound up, and these soon rain out of each, through any bookseller or newsagent, or 24d. each, post-free from the office (except index numbers, which are 3d. each, or Indexes for Vols. I., VI, VII., VIII., and IX., 2d. each. Post tree 2d. each. Indexes to Vol. XI. and to subsequent vols., 34. sch. or post free, 34d. Cases for binding, Is. 6d. each. Breech-loading, Central-fire, Walking-stick Gua. for slide-rest, chucks or tools for sin. centre lathe, or oars ARMSTRONG, Belleek, Co. Fermanag b. Want light Garden Barrow, Wardian Case, and Earthenware Fern Stands. Offer medical coll and battery, electes bells, &c., or microscopic objec ives.-99, City-road. THE TRANSFER CHUCK.-II. By JAMES EDMUNDS, M.D., &c. INCE the publication of my paper on the transfer chuck ("E. M.," July 25), there has been published Vol. V. of "Holtzapffel s Turning and Mechanical Manipulation." This volume contains the first reference to the transfer chuck which I can find in our literature (pages 394-395). It reads as follows: them; the faces and the taper backs of these The paragraph referred to, page 95, "The diameter of the nose being less than upon turning as Mr. Holtzapffel and Mr Burnaby contradict each other, the subject is one which is well worthy of real study. In this case, the questions at issue are bound up with our fundamental notions about the truth of solids of revolution as developed upon that most beautiful tool-the lathe. Mr. Evans, another great authority on all practical lathe matters, favours us with letter 23085. Mr. Evans gave me all the information he could as to the transfer chuck, and he has been most obliging in allowing me unrestricted access to any apparatus that might pass through his warehouse. His letter (page 492) is based chiefly upon a mis-reading of my article (page 453) upon the transfer chuck, and I hope that the following remarks will make all clear. "It has been mentioned incidentally that after the work has been prepared revolving upon the mandrel, it is usual to take a light finishing cut over its surface when it has been transferred to the eccentric or oval chuck. This exact surface truth cannot be said to be indispensable to the majority of deeply-cut patterns, with many of which, indeed, the original surface entirely disappears, nor for many of the solids shaped by considerable excisions of the material; but it is advisable when the ornament will leave portions of the surface untouched, and also to secure the equal penetration of the tool all around the more delicate of such patterns; and as many circumstances combine to interfere with a surface turned on the mandrel under ordinary conditions again running perfectly true when revolving on any of the ornamenting chucks, the small trouble of habitually taking this final light surfacing cut is always more than repaid." "The slight loss of surface truth referred to may, however, be annulled by the means of transfer chucks, the forms and application of which are explained by the diagrams, Figs. 441-443. [See Figs. 1, 2, 3.] The first of these sections represents a care- In the above paragraphs Mr. Holtzapffel fully-made metal spring chuck in which sticks to his peculiar punctuation, and I the work is prepared true revolving on have not presumed to tamper with it. The the mandrel. The true face of this paragraph about "scraping up" the face of chuck, see page 95, Vol. IV., accurately the chuck (Vol. IV. pages 402-3), I have abuts all round against the true face of the already reproduced (E.M." page 299). mandrel, while the back is turned as accur- These quotations are all I can contribute" ately true and to the taper shown by the to the elucidation of Mr. Holtzapffel's they made nozzles interchangeable. On all dotted lines. The section, Fig. 442, indi- teaching as to the principles upon which cates the wheel of one of the ornamenting the set of the chuck upon the mandrel is chucks with its screw, a copy of the mandrel determined, and upon which the transfer nose, carrying the steel transfer chuck; the chucks act in making the nozzles interlatter, shown shaded, occupies rather less than changeable. half the length of this nose, and within it is Whether there is any reader clever enough turned exactly true when revolving with the to understand what it is that Mr. Holtzornamenting chuck, and to the same taper as apffel would teach us on these fundamental that of the back of the spring chuck. The questions, I do not know. For myself, I can last diagram shows the two together, when only imagine that the want of grip and point the taper back of the spring chuck which pre-in Mr. Holtzapffel's language is due to the viously ran true with the work when that fact that he does not himself understand the was prepared on the mandrel, is received principles on which the transfer chuck within the taper fitting in the transfer depends. It will be seen that Mr. Holtzchuck and therefore again runs true with that, and consequently the work again runs true on the ornamenting chuck; the screw nose of the latter now only serves to bind the two chucks together, and the face of the one is not in contact with the bottom of the cavity of the other." The three drawings with which the above paragraph is illustrated (page 394) are here reproduced exactly. "How the Transfer Chucks are made" is upon the lathe in the ordinary way, with a chisel. "Why they are made is, as Mr. Evans says, because" the ornamental chuck will not run truly upon different nozzles without their aid." That with their aid ornamental chucks could be made to run truly upon different nozzles was a fact to which also Mr. Evans freely testified. Mr. Evans is an expert at the manufacture of any lathe apparatus to which he gives his attention, and he will find, on re-reading my words, that I have fully recognised his kind aid on all points. But what I needed to discover about the transfer chucks was "how they acted," not "how they were made," nor why they were made," nor the fact that these points I was quite clear. But as soon as I went on to inquire "how they acted and why they were necessary "if the mandrel faces were true planes of revolution and the screw noses were all " exactly alike as to diameter and thread," Mr. Evans could not help me. His mind took refuge in the proposition that I was right in theory, but wrong in practice." Indeed, he practically reaffirms that proposition, though he is good enough to assist our scientific aspirations by making two model lathe-heads for the purpose of seeing how far interchangeable mandrels can be realised. While we recognise the scientific enterprise which Mr. Evans is displaying, it was necessary to point out that the experts who could make the transfer chucks had never explained the principles of their construction. 66 apffel says nothing about the necessity of turning up a true shoulder-face upon the transferee, nor does he report what I have termed the face-fit. If he has any definite conception of his own as to the real function of the transfer chuck, it is that its utility Mr. Evans need not take this to heart. depends upon the " taper-fit" (cylinder-fit No one, previously to myself, had had the as I have termed this). Now, the Rev. S. audacity to measure out the Holtzapffel B. Burnaby, M. A., formerly Editor of the lathe-noses and to demonstrate how far they Journal of the Amateur Mechanics' Society, were from being "all exactly alike as to Mr. J. J. Holtzapffel goes on to say:— wrote a paper on my proposals for inter-diameter and thread," as stated in the "The system, although tempting, may per- changeable mandrels in the last number of catalogue. Nor had any one before shown haps be considered as almost a refinement, our Journal (No. 25, page 58). Mr. Burnaby that the mandrel-heads of our beautiful inasmuch as equally satisfactory results are there says::ornamental lathes were not true enough to obtained by the final surfacing mentioned "I hope none of our members will waste allow of interchangeability. This not being in the foregoing paragraph; moreover, there his time in attempting it. Perhaps he (Dr. suspected, the transfer chuck was a practical is a sensible loss of stability, so that the transfer Edmunds) got the idea from the transfer fact which, instead of helping us to interchucks are not suited to heary cutting. A chuck; there are some who fancy that the changeable mandrels, only served to show separate transfer chuck is necessary for fit here is obtained between the neck or stem that I was "right in theory, but wrong in every ornamenting chuck, while none can of the chuck to be transferred and the hollow practice." be employed with the ordinary driving or cylinder of the transfer cup chuck; such, other chucks, but only with those especially however, is not the case.' turned true, and to the taper to fit within | Now, when two such eminent authorities VOL. XXXIX-NO. 1,012. In letter 23123, Mr. Wenham contributes some valuable practical comment upon scraping up" the chuck-face. He is, I 66 |