correct. to arise from increased convexity of the crystalline in advance, and then when the work is three-fourths VENTILATION OF BUILDINGS. HENRY W. REVELEY, Reading. TOOLS FOR GRINDING OBJECT GLASSES. SIR,-In almost every number of our inestimable journal we have instructions for making and using telescopes. These instructions are so explicit, and the means apparently so simple that, like Alnaschar, I dream-not of pots, however, but of owning a valuable telescope of my own construction. He demolished the "baseless fabric" of his future grandeur by a kick, while mine is annihilated by remembering that the carrying out of those exhaustive instructions implies the possession of apparatus, the value of which alone would purchase a creditable instrument. A lathe, and skill to use it, are essential for preparing the grinding tools. Now, many amateurs have not these requisites, although from their general aptitude they might be able to grind the lenses, had they the tools already prepared. Now, to go to a foundry and get them cast, turned, and ground, to the proper curves (supplied in ours" for the four different surfaces would cost probably as much, as I see 3in. achromatic object glasses advertised for-namely 458. Were we therefore able to pay for the former, it would be far simpler and more certain of worth for our money, to buy the latter. As this, to many of us, is simply impossible, what I therefore, with your kind permission, wish to propose is, that some kind soul, who has already accomplished the task, should lend us his tools, of course for a consideration, or that some optician should supply us with the discs and the loan of the proper curvature, likewise, of course, for a consideration, for grinding them. J. K. P. SQUARING THE CIRCLE.-"Saul Rymea" says:"The original design of Mr. A. S. Gearing does not, as he seems to imagine, overcome the difficulty of the problem (!). And for this simple reason, that the thick e nds of his wedges will form a square edge, they cannot form a circular edge. For as no portion of a circle is a straight line, it follows, as night follows day, that there will be a vacant space between the line of the 'circle' and the centre of the base of each wedge or isoceles' triangle. If Mr. Gearing will get a metal eircle and endeavour to perfectly fill it with wedges cut according to his diagram he will easily see his mistake. Mr. Elihu Burritt recently made a computation of the amount of time wasted in spelling such words as honour, colour, &c, with a 'u. I wonder how much has been wasted in attempting to square the circle?" GLYCERINE AS A SUBSTITUTE FOR OIL Henry Page says:-"One is sorry to see in the 'Letters BRAZILIAN RAILWAYS.-"Bernardin" says:- SIR, S. Stevens, query 4070, must not look on this present answer to his query as put forward in a spirit of contradiction. 1 have myself been instrumental in supplying some information on the subject to the readers of the ENGLISH MECHANIC, but have not, as a rule, given dimensions for anything. Many different classes of turners are to be styled "amateurs." There are amateur plain turners, then a step further, eccentric men and oval men, and then your aristocratic rose-engine turners and geometric chuck men, till you come to tools that can only be purchased by the tenscore of pounds. There are other amateurs besides, such as I am one of, who have made lots of chucks and things for doing ornamental scratching, but have scarcely ever turned in wood or ivory anything beyond a few foundry patterns and a cup and ball. Now these classes require and must have very different classes of tools. I think really, as a modification of the last sentence, that the best possible foundation for a man to build on, intending to be an amateur mechanic or turner (ornamental or not), would be one of Whitworth's or Muir's self-acting 5" lathes, or a 6 or 7in. foot lathe, double geared, and made specially light for amateur's use. But here is a first outlay involved of possibly £100 to start with, and that of itself would be enough to make many a would-be amatenr pause. And here crops up the money difficulty. Now as to the lathe mentioned by S. Stevens, the design came in the first instance from a gentleman who etands quite in the front of the first rank of amateur machinists, with any quantity of means at his back to produce the best possible result. But lathe making is as much an art as carriage making, and it don't at all follow, because a given maker turns out the best drag in creation, that he is equal to the construction of a dog-cart, and I have been many times rem nded, when looking at amateurs' lathes turned out, even by Whitworth, of Mr. Dent's saying, that when engineers make clocks, they forget that they will not have a steam engine to drive them. And in the case of that GASES EVOLVED BY RIPE FRUITS.-Accordlathe, the designer had not the time or opportunity ing to Lechartier and Bellamy, picked fruits-such as of carrying out the inventions of his brain, and the apples, cherries, and gooseberries-at first absorb capitalist had not the mechanical ability, so the result oxygen; afterwards they give off carbonic acid, and was, that a lathe maker had to be called in to com-in larger volume than the previously-absorbed oxygen. plete a machine which I should think would require At first the evolution of gas takes place uniformly, months of attention and practice to develope the capa- afterwards it moderates, and then ceases for a time, bilities of. The greatest mistake a beginner can pos- and commences again and gives off more gas than sibly make, is to imagine that he can design his own during the first period. An increase of temperature lathe, or can select suitable patterns from somewhere promotes the transformation. Whether light has or other, and have castings made at some foundry or any influence upon the caction is not stated. From other, and then find some workman who can do the these observations it will appear that it is unsafe to work. He will pay quite as much money, all or most sleep in apartments where mach fruit is stored. ARTIFICIAL LIMBS.-The Western Daily Times, in its observations on the Bath and West of England Society at Taunton, says: "Nothing in this saloon (Arts and Manufactures), various and valuable as was everything that had yet appeared, would rival as evidence of extraordinary genius and perseverance, the contents of Mr. J. Gillingham's case, of Chard. This gentlemen, yet a young man, and originally a disciple of St. Crispin, has applied himself to the repair of the human understanding to an extent seldom if ever before achieved by an individual starting from his point in life. He describes himself as the inventor of the "Scapular Arm and Dermatopercha Leg," manufacturer of artificial limbs and surgicomechanical appliances, including instruments for diseases of the spine and hip, club foot, fracture and ruptures, and artificial eyes-indeed only give him any portion of the human frame that has life in it, and he will add all the rest. You are not left at liberty to doubt: there they all are, the substitufrom other people's eyes to discover what skill and tionary limbs before you, and it needs no assistance beautiful workmanship in steel, wood, and other material had been bestowed on their production." REPLIES TO QUERIES. [3714.]-BOILER-J. B. Crossley's reply to "One in a Fix," may stop the humming uoise made by his boiler, but it will not remedy the evil, which is caused by some irregularity of the flues. I have myself been in a fix with the same ash pit, but found the true remedy in rounding all corners complaint. I also tried the perforated plates in front of the and filling up all spaces where the current of air could by any means form a whirl or eddy, which is the cause of the humming noise complained of. If One in a Fix" will examine his fines, and get them made as near as possible of he will find an improvement, and I shall be glad to see his one uniform area, and avoid all sharp angles, I have no doubt report.-W. VARLEY. [3792.]-SEPARATING CHALK FROM WATER.- If T. Grayling, M.D., will place in his eistern a small sheet of zinc, and one of copper attached at one end by solder-say 9in. square, it will cause a deposit of all the chalk, lime, and also all the animalcula contained in the water; it sets up an immediate galvanic action. I have used the same for several years.-NIL DESPERANDUM. [3800.]-PHOTOGRAPHY.-"Would be Artist" will find this plan answer his requirements. The screen should be covered with white paper, sized and varnished. - NIA DESPERANDUM. [3803.] PRIMROSES.-If "J. D. M." wisbes to change soil and plant them in horse-dung, and he will soon get a the colour of his primroses, he should take them out of the very different colour, I see, in answer to this question, S. Rogers says that he is willing to give a few hints on AMATEUR GARDENER. hybridising. If he will do so he will greatly oblige.-AN [8895.]-PARASITES IN CANARIES.-Let "Pakeau water, as it is the cage not the bird breeds them. 2nd. Let scald the cage and everything connected with it in boiling the bird's body (not the head), be folded for a moment in flannel steeped in turpentine, provided he is tame. If not so, let cage be touched here and there with turpentine with a quil top. Flour sulphur suspended in flannel bag from the top of cage is a good preventative.-POOR PIPE COVER MAKER. [3918.] FROM A. STRINGER.-The maker of the veloci pede is Thomas Stanway, King-street, Macclesfield, price £7. It is not requisite to send a design for steering a veloce like a boat, because any blacksmith can reverse the steering handle by bringing it under the frame.-A. STRINGER. plan for the kind of wheels for his veloce. The following [3940.]-VELOCE.-" T. T. M." asks for an opinion on his sketch I give, as I have seen it used:-a is nave, b is axle, works round in have to be fitted square in c ratchet wheel, with thread cut on axle to receive nut to screw on against ratchet-wheel; dstop screwed on nave, e spring to force stop in teeth.-JOHN PARKER. roller made of soft leather or copper-plate blanket-faced with [3941.]-MARKING INK-If "Daisy" (page 262) tries a black silk, I think it will get him out of his difficulty; but I am afraid he will not succeed much with ordinary type; its action on the ink, I think he will soon find, destroys the deep black. What he requires is some silver electrotype, which was used a few years back with a patent marking ink, and found to answer very well.-K. T. Z. [3943.]-BEES.-If the last occupants of the hive died from the severity of the season only, and not from dysentery, "S. W" may safely, and with great advantage, place a swarm in it. The combs of a stock hive very soon become black, but this is of no consequence, though it may be well to cut out a little of the lowest part of the combs. Any mouldy combs, or those filled with old pollen should be carefully removed. S. W. will find much condensed information in "Manuals for the Many, Bee-keeping," price 4d., at 171, Fleet-street. R. M. [3971.]-DISPLACEMENT OF SHIPS.-To work out the displacement of any vessel would take a column of our "voracious journal." The calculations are mostly made by Stirling's (better known as Simpson's) rules. Dr. Woolley's rule is also used; this, though far shorter than, is not quite so accurate as, Stirling's. The whole method of calculation is described, with examples, in Peake's" Naval Architecture," price 3s., published by Virtue and Co., Amen Corner, London; also in "Theoretical and Practtcal Shipbuilding," edited by Professor Rankine, price (I think) £3 38.; and in "Naval Architecture," by John Scott Russell, published at 40gs. -F. W. G. [3972.]-IRON STAINS.-" J. H. P." can take his iron stains out of calico or linen with salts of lemon, which can be obtained at the druggists. The way to do it, is to hold a teaspoon with the conv ex side up, and place the fabric on that part which is stai ned; put a small portion of the salt, and rub it with the finger moistened with warm water, the process to be repeated till the spot disappears. This is an old and well-tried recipe. I have seen it practised with success. -J. M. [3973]-WATER VELOCIPEDES.-They can be obtained at Boniwell's, Richmond. "J. D." should go and hire one for a short time to see how he likes it. But why not apply the principle to a boat? I can send an illustratien of one served in that manner, if "J. D." would like one.-SEMPE R PARATUS. [Send it.] [3986.]-CYANIDES.-I do not remember at present where the fullest information on the direct formation or synthesis of cyanides is to be found; but I can tell "J. W." that though the process is very interesting from the scientific point of view, and was particularly so at the time of its discovery, when it was generally believed that organic compounds could only be produced by vital processes, yet it has no practical value, and is not worked, because at the necessary temperature there is such loss by volatilisation that the process is far more expensive than those usually employed; the other bases will act.-SIGMA. when finished. Now this is the vehicle for graining oak, either light or middle tint, or old oak. The colours used for tinting the above are raw umber, burnt umber, and vandyke brown. The umbers are good drying colours, but the These colours are vandyke is a very bad drying colour. ground in turps, and are mixed, according to taste, either separately or together. The combs are made of horn, ivory, or steel. The veins of the oak are wiped out with a piece of cloth or leather.-HENRY PAGE. [4003.]-WATERING GARDEN. The enclosed rough drawing will, I think, explain to F. H. Jones a cheap method of making a force pump for watering his garden. have had one in use some time. A, common lead pump; B, valve; C, solid plunge from pump; D, outlet pipe; E, small cask, or any suitable air-tight vessel holding about 6gal.; F, valve; G, outlet pipe, reaching to within ab out 2in. of the E K C A D B [4033]-SLIDE REST.-If "J. D. L." will look at my letter of Oct. 15, last year, headed" Levers or no Lavors," he will find a fall description of what he requires.-J. K. P. [4035.-ORGANS.-In answer to "J. N.," I beg to inform him that the sinking of the keys is common, especially in If he will look at the backfall beam be will old organs. most probably find it of oak. The heat of the weather warps this beam, or something immediately connected with it, causing the backfalls to rise. The keys drop in proportion to this rise, and the pallets consequently do not fall enough ta allow a sufficient supply of wind to the pipes. I played on s large old organ of 3 rows of keys for many years, which was to me as good as a thermometer in telling the amount of heat. In the summer, if at all hot, not only did the keys fail, but one of the sliders always became immovable. This was owing to the reason above stated, and to the warping of the upper board, which was of oak. The only remedy for this is to screw up the nuts under the pallet pull-downs. This will raise the keys, but care must be taken if the weather alters to unscrew these keys again, or they will be too high, and the pipes belonging to them will most probably speak. The only perfect cure will be to make a new and much stouter backfall beam of dry mahogany, well secured to the bottom of the wind-chest or elsewhere.-CAMERTON. [4037.]-WHEELS. TO "R. T."-The real practical diameter of what is called the " pitch circle" of a wheel i rather more than the distance measured from the bottom of the teeth on one edge to the top of the teeth on the other edgo, the trifle that I call "rather more "being the amount cut out between the roots of the teeth to prevent the points of the teeth of the wheel with which it works jamming; and the diameters of wheels of the same set are exactly at their pitch-line, proportioned to the number of teeth; so that if your 120 wheel measured 3in. a little less than half-way down the teeth, then the 30 wheel would be in diameter at its pitch line; and owing to there being 40 teeth to every inch diameter, would be called No. 40 on the Manchester wheel guage. In the same way No. 10 has 10 teeth to every inch diameter, and No. 12 has 12 to every inch, and so on. Now for the "addendum," as it is called-that is, the amount the teeth project beyond the pitch line. On the Manchester guage this quantity is always one division of the scale on each side of the wheel, or two divisions for the two sides, added to the pitch diameter. Thus, on the 10 guage a 35 wheel will be 85237-10ths over all; and on the 8 guage a 35 37 wheel would be diameter; and a 75 wheel on the 8 20 gauge would be 5 8 20 65 11 27 27 bottom; K, guide for plunge-rod. It can now be used as a 27 guage would be = 2- It is a mere matter of procommon pump by having a union; an india-rubber or any force to carry a continual stream 60ft. high. The cask, or air-pitch diameter; and the rest, which I call the "addendam," other pipe may be screwed on, and there would be sufficient portion, or what is called a rule of three sum, for finding the round hole in the bottom, with a piece of stout leather J. K. P. tight vessel. may be placed at any distance from the pump; a is the same for every wheel of the same sized teeth.dock-weighted is all that is required for valve.-B. O. Z. [3993.)-BOOKBINDING.-In answer to "Q., Yorkshire," I should prefer handled letters, as when he has once overcome the difficulty of keeping them perpendicular he will find them much more convenient than the brass type. especially when lettering on a well rounded back, as there is then great difficulty in keeping the letters clear without any slurring. If he wish only to letter on the sides, or for labels, then decidedly the type would be best for him. In answer to his second query, I think he will find the following to be about the usual prices; but as it is now 2 or 3 years since I required to purchase, and I have not the bills handy, I cannot guarantee their correctness:-Cloth, 1s. to 2s. a yard; leather, 1s. per skin-skiver or sheep, 2s. 6d.; roan morocco grain, 4s 6d. to 5s.; calf, 9s. to 10s. 6d. He will find that the greatest difference in price is caused by grain and colour. -K. T. Z. [4008.]-GRAINING STUFF.- Vandyke brown in a little beer is the article used for oaken doors; it is termed overgraining.-SEMPER PARATUS. [40081-GRAINING STUFF.-Purchase at the oil shop 4lb. dryers, lb. burnt umber ground in oil, 1d. of orange chrome, pt. turpentine, pt. linseed oil; work up with a knife on a board a handful of dry whitening moistened with oil to a consistency; then add the dryers, umber, and half the orange chrome previously ground up with oil; put all into a pot and thin out with the oil and turps in equal proportions. The more oil and turps added the thinner the colour, and then strain the whole through a portion of the leg of an old stocking tied over the pot. For inside work all the oil and turps must be used, as the colour is used very thin.-BARPHOOGEE. [4008.]-GRAINING STUFF. The easiest method is called oil graining. Take 2 by measure of boiled linseed oil and 1 of turps; to this must be added patent dryers-a suflicient quantity to make it set in 6 or 8 hours. The quantity of dryers will depend entirely on the time of year. He must now grind up some whitening in turps and mix with it, adding a littte at the time; when he finds it beginning to thicken he must rub a little sparingly with his brush on some old paint-work, and draw his graining combs down it. If he finds the comb marks run in, he has not got sufficient whitening; he must keep adding more until he finds, on trial, that the comb marks remain distinct. The whitening is simply put in to make it comb, and not for any other purpose; therefore when you have obtained this do not put in any more, as it only destroys the transparency of the work [4017.]-CRICKET BATS-Willow is the wood used for the blades; when spliced, part wood and part cane is generally used. 1 should not advise "Stump" to try to make them, as, unless he is a good workman, he will undoubtedly make a mess of it.-SEMPER PARATUS. [4025.]-HORSE POWER.-The general rule is to multiply together the pressure in pounds on a square inch of the piston, the area of the piston in inches, the length of the stroke in feet, and the number of strokes per minute; the result, divided by 33,000, will give the horse-power; but it is necessary to deduct about 1-10th of the whole as an allowance for friction.-CUTHBERT. [4027, 4038, 4058, 4063.]- MEDICAL COILS. Being away from home, I cannot refer to past numbers; but some of the questions asked me on this subject have been recently answered, and full particulars given. As to "A Coal Miner's question, it is very hard to say where fittings can be got, particularly where one does not know his locality; the best directions I can give is, make them, which is easily done by any handy person thus, for the part carrying the screw an elaborate brass casting may be employed, but is no better than a simple arch formed of sheet brass, on the middle of which a thick piece is soldered for the screw to work through. My own early attempts (and very successful they were, and of all kinds of odds and ends; even coat buttons were pressed even with some pretensions to artistic effect) were built out into service. The pillar to carry the spring may be made of of a piece of wood turned up to shape and fitted with a screw any stout rod, or even of a thick wire, passed up the middle at the end. For medical purposes "R. T." would find the plainly understood that for this purpose violent shocks are condenser injurious instead of beneficial. It cannot be too would advise "Rather Dall" not to use a water regulator; not desirable, but a full steady flow of mild pulsations. I they are nuisances, and interfere with the last-mentioned principle. It is far better to control the force by a commutator throwing different lengths of wire into action, and by either withdrawing the core or covering it with a sliding brass tube. I think " Inductorium" is mistaken in the meaning of terms. If a wire were wourd in different directions in its two halves, not the smallest effect would be produced. as one half would act directly opposite to the other, and neutralise it. But if we start winding from the middle, it is necessary to wind in what we may call opposite directions in order to make the continuous direction the same, just as it is in the two arms of an electro magnet; so, also, each layer appears in one sense to be in opposite direction to the one above and below it; but electrically it is in the same direction.-SIGMA. [4031]-LEATHER CUTTING.-TO "J. C."-I consider the screw motion better than rack and pinion for your job. The reason for its going hard is the great diameter of the screw. If it were in thick instead of 2 it wonld be strong enough probably, and take less than half the power to work it. I have investigated this subject mathematically, and have arrived at a result that would astonish most engineers, judging at least from what general practice is. I have not yet been able to try practically whether my theoretical result is correct, but have submitted my calculation to Dr. E. B. Denison, who is a practical as well as a scientific man, and he sees no fallacy in it. I have for some time past intsnded to send it to the ENGLISH MECHANIC, and shall do so, I hope shortly.-J. K. P. [4032]-GRIP CHUCK-The chuck, as shown, was for a lathe of bin. centre with mandrel not bored up. I have since made one 2in shorter for a 54in. lathe, the mandrel of which is bored with a in. hole about 6in. deep. Less length would do-say in.-J.K. P. [4047.]-MUSICAL TERMS.-In answer to "J. R. W.," he is evidently not well up in organ stops or the labelling of the stop-handles. The pitch of the principal organ-stops, such as the open diapason, dulciana, claribella, gamba, trumpet, &c., is of what is called 8ft. pitch, because the pipe of these stops to produce CC must be 8ft. long or thereabouts, being a little longer, if the pipe is of small scale, and shorter if of large scale. If you pull out one of the above-named stops, and press down-say fiddle G, you have the fiddle G note, corresponding with the lowest note on the violin. Any stop, then, on the organ or harmonium, which, when drawn, and a given key pressed down, gives you the pitch you expect to get according to the note pressed down in an 8ft. stop, whether it goes through the compass of the instrument or a part of it. The pitch of the human voice and of ordinary instruments, as the piano, violin, flute, clarionet, oboe, bassoon, &c. is 8ft. Now if you pull out the double diapason 16ft., double dulciana 16ft., or bourdon 16ft. (tone), and press down the fiddle G note as before, you will not get the fiddle G tone, but an octave below it. Any stop labelled 16ft., whether it runs through the whole compass of the instrument or a small part of it is called 16ft. pitch, and gives you an octave below the tone you expect to get from a given note. But if you pull out a stop labelled 4ft., say principal or flate. and press down fiddle G, you will not get that note, but an 2ft., and press down fiddle G key, you will not get that note, octave above it. If you pull out the 15th, or any stop labelled but 2 octaves above it. Any stop may or may not go through 4ft., or 2ft. pitch, as I have explained.-CAMERTON. the whole compass of an instrument; but it is of 16ft., 8ft., [4055.]-ORGAN PIPES.-In answer to J. P.," there is no such thing as CCC open diapason. CCC is the lowest of the double diapason, or bourdon, or any other 16ft. stop. desired thickness. Organ builders first cast the metal, then plane it to the Different organ builders have different thicknesses and scales and weights of wind to correspond. The once noted builder, Green, made his pipe very thin, of small scale, with small weight of wind. H organs were very sweet, but of the chamber organ tone, and wanting in the full, bold, ringing tones of the old Father Smith's organs, the pipes of which, as a rule, were of thick, honest metal, and well blown. An organ builder would cut out many pipes from the same sheet of metal, as he would many wood pipes from the same board. A small scaled pipe will always be longer than a large scaled pipe giving the same note. As to the relative diameters of open diapason, principal, fifteenth, &c., no two organ builders are agreed; but the most sensible notion seems to be this, and it was adopted constantly by the best builder in England, has ever seen :-Make the principal one scale less than the open; the 15th one scale less than the principal; the 22nd one scale less than the 15th; and so on. As to a mixture stop, the relative diameter of the pipes depends entirely upon the character of mixture which is wished to be obtained, whether a full or sharp mixture, cornet, &c. The length of middle C open will be about 2ft.; middle C principal Ift.; middle C 15th 6in.-CAMERTON. [4056.]-ELECTRO MAGNETISM.-"F. N. F.'s" question is somewhat obscure. If I understand it aright, the best position for placing the magnets is in the lines of the radii of the revolving wheel-not as tangents to it, because the whole face is brought into near neighbourhood, while in the latter case only the edges would be so. Of course the cut-off should be so arranged as to stop the current slightly before the armature reaches the position of strongest attraction, in order to demagnetise completely by the time it crosses that position, otherwise there would be a tendency at that point to stop the motion. -SIGMA. [4057.]-GALVANIC BATTERIES. Neither the manganese or sulphate of lead battery is at all suitable for the purpose indicated; they will neither of them sustain a current of large quantity for any time. My next paper will probably give the information "F. N. F." wishes for. SIGMA (4068.3-PRESERVING FLOWERS.-"G. O. F." must not expose them too much to the influence of light. He will find no difficulty in "laying them out "if he places them carefully on thick absorbent paper, as soon as possible after collecting, and covers them by bending over them, from one corner, another piece of paper so that as he arranges the petals, &c., he presses them into place. Before they get quite dry, he should examine and arrange any parts that are pressed out of the natural position. I have a hortulas siccus consisting of some of the most minute and delicate leaves and flowers, gathered during the past 8 or 10 years, which are as beautiful as when first obtained.-H. E. GODFREY. [4070.]-THE LATHE.--For answer, see "J. K. P.'s" letter. NOTES AND QUERIES. [4082.1-FLUTE.-I have a flute made by Starke, London, which is nearly a whole tone too fiat; is there any way to sharpen it? I have tried in town here, and can't get it done. The flute has a very sweet tone, and I am very fond of it so don't wish to change, if possible.-J. T. O'BRIEN. [4083.]-CLEANING WHITE CORAL-I have some pieces of coral reef (originally white, I am told) but now very dirty. I have tried to clean them, first by washing them in pure water, then with soap and water. They are still a dirty grey. Will any reader tell me how to get them white, and oblige?-A NEW READER OF THE MECHANIC. 4084.]-COMET.-Having seen a mention in one of the daily papers of the expected arrival of one of these strange bodies, I should feel much obliged if someone among our astronomical readers would kindly inform me in what constellation search should be made first, and whether it would be likely to be visible to the naked eye?-W. R. [4085.]-PERRY'S MICROSCOPE.-Will Mr. E. Perry inform me what is the distance between the lens and the object glass, also where the instrument may be obtained?-SALOPIAN. [4086.]-FITZROY STORM GLASS.-Will any reader publish the formula for making the above?-W. V. YOUNG. [4087.]-GLASS PAINTING-Will you let me thank Mr. Ashton very much for the trouble he has taken? The only thing in which I fear failure is the oxide of gold and calcined sized copies; they are thin. The small one has rays appasilver, may I therefore trespass upon your space and his kind-rently issuing from the heads of the figures ?-A BEGINNER. ness for brief replies to the following:-Where can I procure the above two chemicals purest and cheapest? Does he consider prussiate of potass, indigo, and the earths, burnt umber, sienna, and vandyke brown, permanent; if not, will he kindly set me up with browns and blues?-SABLE. [4088.]-OBJECT GLASS.-Will someone kindly assist me out of a little difficulty, that is, what distances should the lines be, namely: : [4096]-AERATED WATER-Will any reader give me instructions for constructing an apparatus for making aerated water? It is made by impregnating the water with the gas from sulphuric acid (oil of vitriol) and chalk. I want to know how it is forced in to impregnate the water, &c. ?-D. W. L. [4097.]-A VELOCIPEDE FOR SPORTSMEN.-I have been trying to fix on the best plan for a 3 or 4 wheeled velocipede for carrying two persons, and in addition two dogs, for Eyepiece No. 1. in. diameter, in. focus No. 2. lin. 3in, shooting purposes in winter, or a portable canvas boat for fishing in summer. I live in the west of Ireland, and am No. 3. in. 3in. " surrounded by lakes which are at various distances, and freNo. 4 lin. 3in. 39 Stops between 1 and 2, 3 and 4. And what distance should quently it is not easy to find a comfortable or safe stable to there be between 2 and 3, as I have a 3in. achromatic object put a horse in. It would therefore be a great boon to me and glass of which I am satisfied with the night power, but in perhaps to others who are fond of a day's amusement with a rod or gun. Could a really servicable 3 or 4 wheeled velothe day power there is a dianess like a glass out of focus?-cipede be obtained suited for the above? I should prefer G. B. 39 [4089.]-LEVER ESCAPEMENT.-" Nobody" has replied to my question in a sneering, I had almost written, insulting manner; I did not ask for wit, but information. He evidently thinks I knew nothing about what I wrote, and wanted to steal something through the medium of the ENGLISH MECHANIC. Allow me to tell him that I have occasionally seen a lever escapement, and have planted a new one or two, but what I wanted to know was the best way without going far into arithmetic to gauge the "proper dimensions" of the parts of an escapement relative to each other, that is to say, sizes of 'scape wheel and roller, length of lever, place for ruby pin, &c., &c., and the best way readily to get the angle for pallets and lever, and whether the same rules answer for club wheel as pointed tooth escapements. Also in converting a verge or English horizontal into a lever, the best way to do so "supposing the pieces to be already made, for I think nobody would take the trouble to make a lever escapement when it can be bought so cheap rough. The remark-"suits of clothes to fit anybody" was quite uncalled for, as the same gauge or dimensions will answer, proportionably, for all size watches. If "Nobody" cannot, or will not, now answer my question, perhaps, some other practical man will kindly give me the information I ask for.-GRACCHUS. gent ease in propelling it to speed. I hope some of your clever correspondents may give me some assistance in the matter.LAND OF THE WEST. brother reader inform me, how I could emigrate on the [4098.] EMIGRANTS' INQUIRIES.-Will any kind cheap to some healthy colony where I could meet with employment in the building trade. I could, if hard pushed, turn my hand to painting, plumbing, masonry, and many the means to turn out as I would wish.-A HARD-UP WELSH other useful branches. Having a wife and family I have not TRADESMAN. [4099.]-OBSERVATORY-I want to erect an observatory for a reflecting telescope, like the one described in the "Intellectual Observer" of July, 1864. The chief difficulty will be in getting an ordinary carpenter to make the roof so that it shall turn round easily and smoothly. I intend to cover the roof with felt. If any correspondent has ever built one on this plan. I should be much obliged if he would give me the benefit of his experience? The whole cost, including labour and materials, is said in the "Observer" to be under £11.-ALGOL. [4100.]-TOOL FOR SWAGING BOLT AND SET SCREWS.-Will some reader inform me how to make a tool for swaging small bolt and set screws?-AMATEUR BLACKSMITH. [4090.]-GILDING BATTERY.-I wish to thank "Tan" for his information (gilding battery) which he sent [4101.]-DIFFERENCE OF TEMPERATURE BENEATH a few weeks ago, and I have been anxiously looking for the TREES.-What is the cause of the difference of temperature few hints he promised me, as I wish to learn the gilding noticeable in passing under some trees in the summer months. practically, if possible. I tried with one cell, and followed I have often been struck by it, and a few days ago, during a his instructions-heating the bath to about 60° Fahr, put-long drive through Herefordshire lanes, about sunset and ting a piece of gold on wire from positive pole, and a piece an hour or so afterwards, the air was quite chill, but whenever of zine (as I had no platinum) on the negative wire, but I I passed under certain trees, a puff of heat in my face was could get no deposit. Will you tell me where I am still almost startling; indeed, it felt like passing before a fire. I wrong. For the bath I used merely an oz. of cyanide of pot- had no means of testing the difference of temperature under tassium to pint of water, and left the battery for seveaal the trees and a few yards out, but I am sure it must have hours. If he wishes to write to me, I will insert my address been many degrees. I have only noticed the above on in the Sale column, or a drawing how to arrange the battery summer evenings.-K. will oblige.-ONE IN A FOG. [4091.-PLAN OF CANOE.-I should be glad to take advantage of "Boat Builder's" kind offer to send a plan of a canoe, and to communicate with him direct if he would write to me.-J. F. O'BRIEN, 32, Lord-street, Liverpool. [4092.]-THE ENGLISH CONCERTINA-Would our worthy friend "The Harmonious Blacksmith," or some other musical correspondent, kindly explain the merits of an English concertina? Are they really musical instruments, and the best substitutes you can get when circumstances will not allow of a piano or organ?-LOST. [4093.-RANGE OF PROJECTILES.-How much rise, or fall, there will be in a plane, on which a cannon is fired, to be equal to 1 degree, on the tangent scale, as I find when practising on a tidal river at a floating target, the range is very much affected by the rise and fall of the tide, which is caused by the elevation of the plane? If the tide is lowering the range increases, and, if, on the other hand, it is rising it decreases in a similar manner. Not having seen the deviation noted, I shall feel obliged by your answer, in one of your [4102]-GALVANISM.-Wanted to know best works on medical electricity, and prices of same, and publishers. Also how to make a galvanometer ?-T. B. [4103]-CLOG IRON MACHINE.-Could any of our readers give a description of one of these machines, so that I may make one?-LANDAMINI. [4104.]-BEES.-Will" Anon" be kind enough to inform me where I can obtain " mends in MECHANIC of June 10?-A BEE KEEPER. Payne's Bee Book," he recom[4105.]-HALL MARKS.-Will any brother reader kindly inform me where I can procure a book containing the hall marks, so that I might be able to tell the dates of old plate, &c., and about the price of such ?-CATSEYE DIAMOND. [4106.]-GOLD COINS OF EDWARD IIL-What is the value of a gold noble of Edward III?-CATSEYE DIAMOND. [4107-]-KNIFEBOARD.-What is the cork composition fastened on the knifeboard with ?-CATSEYE DIAMOND. 4108.1-WHAT COIN IS THIS?-Brass, about the size of our penny, the inscription Jacobus II, Dei Gratia; rev.: a crown with crossed sceptres, on one side I and the other R, over the crown 1689, XXX, below Aug. I, round the coin, Mag. B.K. Fra et. Hib. Rex. ?-CATSEYE DIAMOND," [4109] TELESCOPE CONSTRUCTION.-I shall feel very thankful to anyone who will inform me what is the price of a disc of flint glass, and a disc of crown glass, 6in. diameter, of good quality, at Mr. Chance's, Birmingham, or Powell's, in London? What should be the diameter of my brass tools for working an object glass 6in. in diameter? How can I tell when the glass is ground sufficiently well to commence the polishing; is it possible to grind the surface of the glass sufficiently smooth with finely-washed emery to reflect an image of a star like I can get in working a metallic speculum? Can I employ a coating of black pitch spread on the tool as a polishing bed, or will it be likely to press out at the edges, and so prevent the getting of a true spherical figure; which ought I to employ from among the various other polishing beds which I have heard proposed, such as cloth, linen, alpaca, lute-string, silk, &c.? How long ought a lens, 6in. in diameter to take to be polished, using putty powder?URANUS. [4110.]-MAGNETISM.-Allow me to call the attention of haps "Sigma" will kindly give his opinion. If a wrought your readers to the following as relating to this subject; periron ring be surrounded with a helix of covered wire, I think it will be admitted that in this case, from its symmetrical form, there is no reason why the magnetism should be more strongly developed in one part than another. If, now, the ring be cut through transversely (without severing the wire) so as to form two horseshoe magnets, it will be found that iron-filings will only adhere around the severed parts, even when the same are pressed firmly together. How can this be explained? The ring with the halves in contact has remained the same as before, with the exception that the cohesion has been destroyed in these parts. Does not this point to an influence that mere severance or destruction of cohesion has on the distribution of magnetism, or on the formation of poles? 1 cannot see that Ampere's theory throws any light on this case. I have not in my readings observed any mention of the following fact: If one end of the secondary of one of Rhumkorff's coils be insulated and the other end connected to earth; the core, primary wire, and everything in connection with it, battery, &c., takes an electric charge. With a coil giving in. sparks, the battery gave with the above arrangement strong sparks in long. With a large coil a most unpleasant shock would certainly be the result of touching the battery with the arrangement referred to?S. T. PRESTON. [4111.]-EMIGRATION-TROPICAL CLIMATE.-Could you or any of your numerous correspondents kindly indicate where I could meet with sound information on the following point: I am desirous of emigrating, but from descent and constitution could succeed only in a tropical climate. I am therefore desirous of learning the price of land and other necessary particulars in Jamaica, Trinidad, and British Guiana.-ORIENS. [4112.]-GAS METERS.-Will any brother reader be kind enough to give me a description and drawings of the working parts of wet and dry gas meters? - An INQUIRER. [4113.]-PHOSPHATE OF LIME.-What is the use of the phosphate of iron arriving in London and in Bristol from Portugal. A few particulars will oblige?-PHOSPHATE. [4114.]-METRICAL ACT.-I wish to know the date of it, and especially the official proportion of English and French weight?-INQUIRER. [4115.]-TROPICAL FIBRES.-A work has just been particulars on it, where I can get it, price, &c. ?-J. C. P., edited on them in England. I shall feel obliged for some Paris [4116.]-AN AIR-STRUNG PUMP.-I have for some time been greatly puzzled with a common pump, often improperly called the sucking pump. The pump stands about 50 yards from where it gets its water, and of course there are 50 yards of pipes, with a valve near the end of the pipes. Now, this pump often becomes what is technically called airstrung. The pump does not lose its water, but it is in a manner locked. The fact is, when the pump is in working order one man can work it with ease, but when it is airstrung it is absolutely impossible for two men to work it. I shall feel greatly obliged if you, or any of our excellent correspondents, will kindly explain what it is that causes this pump to become air-strung?-COAL MINER. [4117.1-BULLION IRON CEMENT.-I should feel obliged if any of our correspondents could tell me of a material called bullion iron cement? I think it is not used to prevent radiation of heat, but to coat the metal of the boiler. I am told it is a heavy yellow powder. I should like to know where I might see any ?-R. G. B. [4118.]-PROBLEM.-"Gimel" will much oblige if he will be so kind as to give a solution to the following problem without the aid of algebra? A gentleman having mortgaged an estate for £2000, at 5 per cent. compound interest, he is now desirous of knowing in what time he shall discharge the said debt and interest by paying the mortgagee £187 yearly? -ALGEBRA. [4119.]-ANASTATIC PRINTING-POROUS CELLS.Will any fellow reader kindly inform me whether the zinc used for anastatic printing is prepared in any way; if it is I should be obliged to anyone to tell me the way to do it? CUTHBERT. [4120.]-FLY PAPERS.-How are fly papers prepared-I mean papers for catching flies, which disturb us so much at this season of the year?-HAWTHORN. [4121.]-TO BOTTLE FRUITS.-I wish to know how to bottle fruits such as those done in the clear liquors. Will any reader kindly favour me with the exact process?-SEMPER PARATUS. [4122.]-DISTILLED WATER.-Will any reader kindly inform me how to distil water on a small scale for photography?-MOSES. [4123.]-SOLDERING BRASS.-What fluxes are used for soldering brass?-MOSES. [4124.]-FOLDING STOOL.-Will someone inform me the best principle on which to construct a folding stool for an office desk-one to slide under the desk is what I want. A sketch would oblige?-TIRED LEGS. [4125.]-SCREW CUTTING-How could I cut an odd pitch in a screwcutting lathe without using a reversing strap. I have tried to do so by bringing the carriage back to the same place, but find that the tool will not pitch always in the same thread. And also the same information as to the fractional part of a thread?-ANXIOUS. [4126.]-WALL BAPER-What is the best material to put on damp walls to keep the paper from being tarnished?A CONSTANT READER. Per C. E. Cæsar .. C, J. H. C. 070 0 10 0 0 0 0 1 6 1 0 0 £189 12 7 1689 A. F. Brophy, 42, Redcliffe-road, West Brompton, improvements in staining and ornamenting wood 1890 D. Greix and J. Greig, Edinburgh, a new or improved machine for dressing and separating the fibres of certain fibrous substances. the same being specially applicable for treating rhea or china grass-A communication 1891 B. J. 3. Mills, 35, Southampton-buildings, improvements in steam and other vessels, and in steam engines, steam boilers, and propellers applicable thereto.-A communication 1602 F. W. Granham, and B. Butterfield, Bradford, improvements in muzzles for dogs 1693 K. Punshon, 3, St. Nicholas-buildings, Newcastle-uponTyne, showing the local deviation of the mariners' compass in iron and other ships 1004 M. Henry,168, Fleet-street, improvements in spectaclesA communication 1605 D. C. Lowber, Church-street, Warrington, improvements in machinery for manafacturing wire ties for securing bales 1606 W. R. Lake, improvements in rudders for vesselscommunication 1697 E. T. Hughes, 123, Chancery-lane, improved methods. soda in its crystallised state.-A communication A FARTHING A WEEK-Mr. B. Edwards, who sends us a The following are the initials, &c., of letters to hand up to W. and B,-Tickets for the dinner returned. We are adverse to bribing and puffing of all kinds. Giving dinners to the representatives of the press" is in our estimation a species of bribery. GROCER wishes to have his thanks recorded to "J. K. P." B. J. WILLIAMS.-The address of Beck and Co., is Cornhill, J. R. L-Try again. There is every probability you will be J. H., T. W B. and others.-Mr. Perry's address is, 8, most We G. GILLINGHAM.-See extract in "Useful Notes." always like to give an esteemed correspondent a lift if we can honestly do so, J. H. MORGANS, Parklands, with photos of turned work. W. PEARSON and Co.-with description of new lock-stitch sewing machine. VENCEDOR.-The journal you mention ceased to appear about two years since. A. MILLER.-The machine was an American invention. W. S. GREENWOOD.-Exchanges are paid for, and not in- THE SIXPENNY SALE COLUMN is the only place in which CUTHBERT.-First query inserted. For second, see recent papers on "Electricity." BARPHOOGEE.-Queries asking where various articles can be obtained, can only appear in the "Sixpenny Sale Column." CHARLES.-Both your queries have been asked and answered during the time you have subscribed. SUBSCRIBER (Northampton).-Advertisements cannot appear as replies. WOOD ENGRAVER.-See last volume. THE INVENTOR. WEEK ENDING JUNE 14, 1870. 1639 L. Rose, 5, Bank, Leith, an improved stopper for bottles West, 7, Lidington-place, Oakley-square, improvements in 1642 B. Holt, 14, Savile-row, improvements in horse-shoes and 1643 E. Doughty, 66. Welbeck-terrace, Nottingham, improvements in lace machines 1644 G. T. Bousfield, Loughborough-park, Brixton, improvements in the treatment of slag and other vitreous material.-A communication 1645 J. Morris, Belfast, improvements in machinery for shed- 1646 T. Aveling, and H, Rawlinson, Rochester, an improved 1649 W. R. Lake, Southampton-buildings, London, improve- tion 1650 A. Piccaluca. 82, Boulevard Sebastopol, Paris, improvements in apparatus for manufacturing iced syrup or cream, and soda-water beverages 1651 G. Lodge and G. Sheard, Leeds, improvements in steam boiler and other furnaces, fire bars, and flues 1852 H. W. Hammond, Manchester, improvements in cartridges. A communication 1653 E. Clarke and J. Hughes, Ponkey, improvements in safety cages for mines and shafts 1654 W. Dewhirst, T. Dewhirst, and J. Dewhirst, Bradford. an improved stop motion applicable to machinery or apparatus 1655 E. Green and J. Cadbury, Birmingham, improvements in collar and shirt studs 1656 H. Boltinger, Manchester, improvements in machinery for dividing and condensing fibrous materials on carding engines 1657 W. R. Lake, improvements in printing telegraphic apparatus.-A communication 1658 W. E. Newton, 66, Chancery-lane, improvements in cart- 166) J. H. Johnson, 47, Lincoln's-inn-fields, improvements in 1603 W. L. Wrey, United Service Institution, Westminster, 1664 J. W. Butler, Stonebridge-park, Willesden, W. D. Butler, Princes-street, Hanover-square, and J, Dudbar, Vicarage-road, Camberwell, improvements in machinery or apparatus for supplying coal, cannel, or other substances to gas retorts or ovens, and for withdrawing the same after distillation 1665 J. Scaife, Leeds, an improved packing for pistons, piston rods, and other rods 1868 W. T. Wright, St. Nicholas. Glamorgan, and B. Yorath, Molton, raising and lowering, loading and unloading hay, corn, J. BIRD. Find the contents in cubic feet and reduce to gallons. One cubic foot contains (approximately) 6 232 gallons JACK RAG-A book (now advertised in these columns) sold by Mr. Crowther, of Halifax, will give you the information you require, also a book by Mr. Binns (likewise advertised and reviewed in this number). R, N.-See answer to "Cuthbert." A FOUR YEARS' SUBSCRIBER.-You may become a dentist by apprenticing yourself to some member of that trade, and a solicitor by becoming articled to a solicitor for a certain number of years (usually five), and then passing the necessary examinations. H. C. DAVIES.-Consult indexes. R. B.-The "Commissioners of Patents' Journal" will give the information you require. W. B. D. asks the somewhat curious question, from what R. SMITH.-A purely commercial query. Advertise. PEDESTRIAN says, "What a happy suggestion of yours about 1067 W. Fisken, Stamfordham, Northumberland, and T. R. H. Fisken, Leeds, improvements in machinery for cultivating land by steam or other power 1668 Z. T. Gramme, and E. L. C. d'Ivernois, Paris, improve- 1669 F. W. Webb, Bolton, improvements in ladles for molten tion 1071 O. C. Stone and W. Pridgeon, Odessa, Russia, improvements in apparatus for governing and controlling steam engines 1872 W. Kay, Edinburgh, a new or improved machine for washing and cleansing floors and other surfaces 1673 J. D. Branton, Leighton-crescent, Kentish-town, improvements in the ventilation of tunnels 1674 C. A. Calvert, Manchester, improvements in the means of checking and indicating the number of passengers carried by an omnibus 1675 W. E. Mewton, 66, Chancery-lane, improvements in steam boilers -A communication 1676 P. Spence, Newton Heath, Manchester, improvements in the manufacture of alum 1677 J. H. L. T. Portner, Regent-street, improvements in the construction of cabinets, stands, or receptacles for sewing machines.-A communication 1678 H. R. Fanshawe, 14. Finsbury-place, an improvement in towels, rubbers, and wipers 1679 R. T. Y. Johnson, Stockton-on-Tees, improvements in 1680 J. T. Parlour, Brooklyn. New York, improvements in 1882 B. Hunt, 1, Serle-street, Lincoln's-inn. an improved 168 J. Walker, Mansell-street, Aldgate, E. Ragon. Cottage- 1685 T. Green wood, Leeds, and J. Keats, Leek, improvements nse wing machines 1886 F G. Fleury, 21, Merrick-square, Southwark, improvements in water waste preventers 1687 W. R. Lake, an improved embroidering attachment for sewing machines.-A communication 1688 J. Combe, Claremont, Leeds, improvements in machinery for winding cops for weft or warp, or other purposes 1608 F. J. Knewstub, 33, Saint James-street, Westminster, improvements in travelling and other bags, cases, and boxes 1000 G. Lewis, Kettering, improvements in reaping or harvesting machines PATENTS SEALED. 1073 W. R. Lake, improvement in brakes and starting apparatus for railway carriages -A communication 3561 J. Hamilton and R. Paterson, improvements in eolapa. able casks or vessels for contwining fermentabie and aerated beverages 3575 R. J. Ransome, J. Deas, and R. C. Rapier, improvements in tramways 3588 H. Cockney and F. C. Cockney, improvements in steam boilers and in the setting thereof 3590 H. Wilson, improvements in machinery for cutting timber into pieces 3591 W. Williams, improvements in subaqueous and tunsel communications 3605 J. Ga.dner, an improved mode of cutting veneers.-A communication 3617 G. W. Honeyman, an improved preparation for the removal and prevention of incrustatiou in steam boilers 3673 H. Kinsey, manufacture of surface condensers, hotwater apparatus, and steam boilers, and water heaters for the 3000 P. (C. Evans, and H. J. H. King, improvements in apparatus for feeding fibrous materials to carding or other machines 3007 J. Livesey, improvements in street tramways 3613 R. Morton, improvements in refrigerators or apparatus for cooling liquids 3619 N. P. Burgh, an improved double or single acting pump 3624 J. Hamer, improvements in steam engines 3627 J. H. Sams, improvements in seed sowing machines and manure distributors 8629 E. T. Hughes, improvements in wood-moulding and panelling machines -A communication 3633 J. H. Johnson, improvements in means or apparatus for reducing friction.-A communication 3613 5. A. Buirat, an improved process for producing engraved metallic plates for commercial indications 3668 J. O. Ramsden, improvements in looms 3676 W. L. Wise, an improved instrument for leveling and for measuring angles.-A communication 3679 M. Henry, improvements in the mode of and apparatus for typographical composing and printing.-A communication 8689 A. M. Silber and F. White, improvements in apparatus for indicating time 3702 J.Loader and W. H. Child, improvements in steamboilers 3703 J. Pritchard and J. Collins, improvements in embroidering or sewing 3706 J. Brooke, an improvement in the manufacture of blankets 3747 F. W. Webb, improvement in mills for rolling and crushing metals 3766 J. O. Butler J. Nichols, and W. Heslop, improvements in the manufacture of tyres and hoops for railway wheels 82 O. Vivier, improvement in means or apparatus for measur ing and indicating the distances travelled by vehicles 104 A. V. Newton, improved apparatus for preparing abrous substances for spinning-A communication 106 A. V. Newton, improvements in machinery for preparing fibres for spinning.-A communication 110 W. F.Chapman, improvement in cases or apparatus for transmitting and exhibiting cut flowers 154 T. P. Balls, improvements in apparatus for moulding and compressing substances for artificial fuel 597 R. S. Norris, improved method of getting coal 911 W. McNabb, improvements in bale hoops and other bands 941 W. McCraw, improve nots in photography by processes which combine printin, ainting, and transferring for the production of chromo hotographs 976 J. Shackleton, rovements in utilizing exhaust steam 1152 W. R. Lake, improvements in condensers for mariue steam engines arms 1168 E. Farrington, improvements in breech-loading fre1171 J. R. Clark, machinery for knitting stockings or various other articles 1191 S. D. Tillman, improvements in boilers, air heaters steam condensers 3635 E. Tomlinson, improvements in furnaces for preventing the formation of smoke 3637 W. T. Henley, improvements in protecting telegraph wires and cables 3647 A. R. Stocker, improvements in stoppers for infant's feeding and other bottles 3650 G. Weir and J. Weir, improvements in slidelvalves 3654 E. A. Ingiefield, improvements in hydraulic apparatus to be used on shipboard for utilising the pressure of the external water 3655 J. L. Hancock improvements in apparatus for crushing or breaking bones 3662 W. E. Gedge, an improved system of pessary.-A com munication 3663 W. Hargreaves, certain improvements in steam boilers 3661 W. Foulds, improvements in apparatus to promote cir custion in steam boilers -A communication 3677 J. Robertson, improvements in machinery for treating and shaping metals 3683 W Morris, improvements in permanent way of railways and tramw≫ys 3699 W. Ferrie, improvements in blast furnaces 3740 S. Dixon, improvements in the manufacture or production of skirts and pettico its 3753 C. Gordon, improvements in the construction of breechloading re-arms 3761 H. N. Maynard, improvements in piers or supports for bridges, viaducts, and such like structures 3765 W. Helwell, J. Helliwell, M. Helliwell, and T. Helliwell, improvements in the construction of bobbins used in machines for spinning, doubling, and twisting 3771 J. R. Wixham, improvements in gas burners for illuminating beacons, buoys, nud ighthouses 3782 T. F. France, improvements in the construction of baths and waterclosets 9 C. Drake, improvements in the construction of concrete buildings T. Nuttall and R. Nuttall, certain improvements in the manufacture of counterpanes The English Mechanic AND MIRROR OF SCIENCE AND ART. FRIDAY, JULY 1, 1870. MICROSCOPICAL JOTTINGS IN TOWN THE WORLD, ITS FORMATION AND WH BY ARTHUR UNDERHILL (Continued from page 314.) To these, accepting our Editor's published invite, I beg to dedicate the few rambling notes which, with his permission, I will from time to time publish. I may here premise that my notes shall be simple transcripts of my real home work or my field work. They shall be the chat of a worker to other workers, not treatises to amuse the learned. or is strongly supported by observed facts I have here a" waste of water;" destroying all animal and vegetable life, and burying the remains deep in the new strata formed from the ruins of a former world, there to become these fossils which now serve as the historians of their times. Another creation takes place, and a new, and superior organic world occupies the position of the former one. Again a convulsion, and another creation, and so on through a long period of time; each epoch producing life in forms approximating to the present inhabitants of the globe. As Lucretius says So things by turn increase, by turns decay. Like racers, bear the lamp of life, and live, And their race done, their lamp to others give. At length man himselt, and the present races of animals and vegetables were formed, and then, for the first time on earth, appeared that mighty attribute of humanity, reason. I have in the foregoing paragraphs, slightly sketched the history of the globe, a history which is proved both by the different races of organic life whose remains are found in the form of of the strata by the igneous masses which were fossils, and also by the disturbance and rupture emitted at each convulsion. That these con vulsions did take place at different periods, is proved by the different upheavals of the crust, FIG. 2 B thus in Fig. 2. The disturbance at A must have taken place before that at B, for when the convule son at A happened, the top stratum could not have been deposited, for it would have been tilted up with the other strata ; but when the upheaval at B took place, it must have been formed, for it was inclined by it, together with the underlying strata. the convulsion at A happened, and did exist when Since, then, this top stratum did not exist when that at B took place it follows, that the convulsion at A was, in point of time, prior to that at B, therefore A and B were the results of two different convulsions. Since all stratified rocks must have been formed under water, we find that there are certain groups or systems of formations. The localities of such systems are by geologists termed seas, on account of their having originally been the beds of oceans. Between each convulsion, the sea deposited a system; and thus wherever we find the same system in two places apart from each other, we may rest assured that both were under water at the same period, viz., that of the formation of such system; and wherever we find no traces of such system, we conclude that at the time of the formation of the system, such place was dry land; otherwise we should find a deposit of the system upon it. As this subject is of great importance in geology, I shall reserve any further explanation of it until my next chapter. (To be continued.) SCIENCE FOR THE YOUNG.* After this convulsion, the sea charged with the debris and detritus, deposited it evenly on its bed; first the heavier portions of matter, then the lighter ones, and thus a succession of strata was formed. At length, after several of such convulsions had taken place, the earth became in a fit By the Rev. C. KERNAN, CLONGOWES COLLEGE. state for land animals and birds, which were accordingly created; first in a rude and elementary fashion; huge misshapen lizards, or saurians, "wee tiny" bit on our glass stage plate, moisten as they are called by entomologists and birds, whose L it with turpentine, cover it with our thin glass, and wings were but half formed. In these early days W. POCKLINGTON, Hull. (Continued from page 319.) AW V. By law IV. the two forces tend to Law I. a force equal and opposite will keep that have an effect equal to their diagonal. By diagonal in equilibrium, therefore it will keep the two forces in equilibrium. Experimentally the two forces P and Q, Fig. 61, act upon the body A drawn away, for the moment, to some angle, and held-dotted line-to the base B. parallelogram, the sides of which (p and q) represent the relative strength of the forces, and the angle at which they act. Measure the diagonal (r), its length shows the force of the resultint. Trace a the forces P and Q, as the diagonal is proporHang to the hook H a weight proportional to tional to the lines which represent P ani Q. *All rights reserved by the Author |