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employed and situated, who have used intoxicating drinks as beverages, and our unprejudiced orlnion has been and in, that tbn abstaiuor» wore stronger anrt healthier mon—Ed. EM.]
[2512.]-SODA CRYSTALS.-Thanks for G. E. Davis's able article in No. Ml of your publication, but not having any drying or hen ting apparatus, I must abandon the idea of commencing the manufacture and having two pans, both idle, one to contain 120 gallons and the other about 8", I should like to know how to manufacture an article of simple process, and marketable, to keep them aping these bad times. Being no chemist myself, probably G. K. D. would kindly «oggest something.-SODA Crystals.
-TAR DISTILLING.-TO "FEU FOLLET —Will " Fen Follet" be so kind as to describe to me the process of tar distilling: how loBg it is boiled before the pitch Is run off ; how to separate the articles when the pitch is run off. snch as naphtha, oil, benzole, carbolic acid, ammonia, crude anthracene , Ac, or where can I procure a book that will tell what I wish to know; the price, and where to be had .' —T. Brown.
Г2514.]-ЗР1СЕ MANUFACTURING.-Would any brother reader tell me where I can get the information how to mnke spice, or where I can get a book to tell me; also the means to colour it, price of book, and where to be had ?—T. Brown.
[25151—BOILER— A few days age I was told that if a boiler, the first time it is used is made to get up steam quickly, it will ever afterwards be easy to get np steam. If, on the other hand, the boiler is heated slowly on first using It, a difficulty will always be experienced in generating steam. Je there any truth In this statement, and if so, what is the reason ?—W. H. Thorpe.
[25)6.]—EXPLOSIVE COMPOUND.—Are there any two liquids, inex plosive in themselves, which will, when mixed together, explode directly, or become capable of being exploded ; if so, what are they? In what proportion bhouid they be mixed ?—E. Kennedy.
[25ir.]-ELECTRIC ENGINE.—Is there such a thin" as an engine worked by electricity of one horse power' What is Its total size and weight? What the cost, and where could it be bought ?—E. Kennedy.
ГМ18.1 -GAUGE FOR A KITCHEN BOILER. —Would it not be a useful and comparatively inexpensive thing to affix to all common kitchen boilers a small water gauge? It might be secured from fracture by being loosely cased in the manner of spirit levels, and its action having been once explained to the kitchen servants, I feel sure that many a boiler would be saved from cracking and ueelepsness. Is there any objection to this idea beyond that of cost ?—A. C. G.
—VULCANISING INDIA RUBBER.—Will one of your readers kindly inform mo how to vulcanise India rubber? Ca» the apparatus used by dentists for hardening vulcanite (which I possess) be used for the purpose, and how ?—Gummy.
[2520 ]-WATERPROOFING PAPER,—Can any of ray brother readers inform me of the best method of making paper waterproof ?—A. Speight.
[25211-CURIOUS AFFECTION OF THE TEETH. —Can any reader tell me the cause of the following strange affection of my teeth? Some time back a rough deposit began toj>o deposited on my teeth, till it had accumulated to the thickness of a sixpence, gradually covering the tooth and eating away the gum all round until the tooth fell out without pnln, and scarcely any loss of blood. Nine of my teeth have fallen out iu this manner. A druggist whom I oouaulted told me it was canker, and a doctor said it was scurvy; neither of their remedies did me any good. When the limelike coating, with which the tooth is covered, is scraped away, the tooth beneath appears to be as perfect as ever. Will some one help mo, and prevent the loss of the rest of my teeth?—Subscriber From The
[2522.J-SHEET IRON RUDDER.-Will a correspondent kindly say whether a sheet iron rudder for canoes is found efficient and durable ; if so. will he kindly state dimensions for a canoe 15ft. long?—H. C. Rogers.
[2523.]-RUST IN WATER.—BREWING.— Will any of your numerous readers Inform me the way to construct a cheap filter, which will separate rust from water ; also has water, impregnated with rimt. any injurious effect on the brewing of ale, especially as to flavouring it in any way -, also the best and cheapest formoi attemperator for checking the rise of heat In a fermenting square, dimension» Oft- square, aud 5ft. deep, usual length of brewing 25 barrels, temperature of water direct from the well 53= ?—Cromwell.
[2524J—LONGITUDE.—Willsoine reader tell me
■ reader-1 srive Me
forma r.l tires "r
prising. Can any of your
tion as to the durability of the India-rubber wh'
I have Been on hand-trucks at railway stAlious similar
tires. How do they wear? I should bo afraid the rough
stoned roads would destroy tho tiro оГ the steamer. Also
although tho tires doubtloas will expand nadar the près
sure of the steamer, still the weight must b" there, aud
how can they be prevented sinking on soft laud?—Aoiil
[2531.]—BRAZING CAST IRON—The impression fol April 8th contains an answer to my query from '• Blue Euln-" my beet thanks to the correspondent for his kindness. The method of laying the work in moulding sand will not snit my purpose, and pouring melted iron over the joint is not what I should term •' brazing.'' I will define more particularly tho information I seek. I ver)' frequently have to repair important bright parts оl machinery, cast iron (small piece» generally). The defects are caused by frictioa I file a slot in the cast iron and fit a piece of wrought Iron in На place to compensate for wear. My difficulty is this: I cannot got the spelter to unite the caet and the wrought iron—it has an affinity for the wrought iron, but will not take on the cast iron. It can be accomplished I am certain, as I have seen specimens of casuiron ■ nootly mended by brazing pieces of wrought iron to compensate for woar. For the information of St. George, I can assert that the process of Mr. Ai-mitago, of Kirksuill, for case-hardening, is not new. I have seen prossiato oí potass used in the way described twenty years since. I always use prusslnte of potass for hardening my work (wrought iron), if there is muoh friction, especially bolts and pins,—ReciProcity.
[2S32.]-LEAD FOR « BELWOT'S" ENCHNE.-CTo Mr. Baskerville.)—Allow me to congratulate Relwot for obtaining such an excellent and valuable answer from our good-natnred correspondent, J. Baskerville. Such an answer is worth pounds la The Esolish Mechanic, not only to Relwot, but to others as well. I wish to ask J. B. one question—Why wonld he give so much lead to the valves of the engine in question? I should have thought i in. lead decidedly too much for any stationary engine, except it was a very high piston speed, as in my opinion the piston saccd is the main point to bo considered when deciding the proper lead for an engine. But I should much like to вее the question of lead well argued out in theso oolumns by some one that can fight, for scarcely two engineers seem agreed upon this point. Will J. B. kindly give me a single rule to find the proper weight and Bize of engine fly wheels ?—Steam Spibit.
[2633.]—COCOA-NUT.—Wilt one of your numeróos readers be во good as to account for the milk in the cocoanut?—Minnehaha.
[254.;.]-THE XIOOL PRISM.—"TLo Niçois grisma. which our readers will have seen mentioned so ofwn in tae recent paper« of Professor Tyndall. «re expensive tu obtain o( any size. They are made of a crystal ol odespar, ont across diagonally, tho two sections being afterwards joined together by means of Canada balsam. U has recently been discovered that a prism, possessing tho sama optical properties, may be made by eouslructiug а vessel of glass, inserting a thin plate of calc-epar aeróse tho diagonal, the vessel being filled up with bisulphide of carbon. If this 1)0 so. Nicol's prisms of considerable size may bo made cheaply, since blocks of calc-spar of considerable size are often met with."—Menante*' Magazinr. February 2ti, WTO. I cut the above from л scieutifie periodical. Has anv subscriber met with it. and, if so. I should be glad to obtain further details ?—Carthusian.
[2541.]—HEATING WATER IN BATHS,—In there net a patent apparatus to be placed in a bath to heat It in a ehort time?—A. M. M.
-EMIGBATION TO NEW ZEALAND.—Will "Josh." "H.Coggini," or any reador, favour me with а few hints, as I am going to emigrate to New Zealand Ï I have saved £18, and I am a single young mm, a Jack oi many trades, but master of none.— W. STONE.
[2546.]—BATTERN-MAKING,—\ЧШ anyone be kind enough lo tell me if there is any work published on •• Pattern-making? If so, the price, and where tobe had.— Galloway.
[2*47.]—PRINTING NAMES ON PLANS.—Will somebrother reader be kind enouzh to inrorm me of a method of printing the names of fields, trees, &e., on plans of estates? I have lately used a printer's p illet and type, but with not much success.—Land Surveyor.
[2548.]—GILDING BATTERY.—Will any reader lenil me a little assistance? I have a gildingbattery, Daniell'» two cells, and cannot get it to work, as I am in error somewhere. Thecoppercellsareabout Jofanlnch larger In diameter than the porous pote, which are 'Ц inches across. I have put sulphate of copper round ontside of pot n»afly half-way up, and banked round at the top on the copper rim, that keeps the pot npright, and filled np with water Inside the pot to Immerse I4e poles. I put oil of vitriol and water, one part vitriol and two parte water; but I could get no action on the poles. The wirea—one from
eaeh were ordinary stout copper, and I led them iuto
some strong cyanide of potassium dissolved In water, and kept it over a gas-burner, putting a piece of 22-earat gold on one wire, and the article I wished to gild on the other, but I cou'd make nothing of it. If any reader will se: me right I shall feel extremely obliged.—One Ix A Fo«.
[j549 ¡—SCREW STEAMER.—Will one of your readerbe kind enough to inform me whit horse-power i« required Tor a screw steamer to carry from four to si \ persons and whether an ordinary horizontal engine will convert for this purpose ?-Docr,LAB M'carthy.
[2550.]—ETHEREAL GOLD SOLUTION—I am very much obliged to "Sigma" for the information he has imparted, but he has not answered the last questions, «s to the means of applying it. and whether ibc steel requires any preparation. If he will do so. he will very greatly oblige.—B. S. Bt.'ttDKN.
[2551.]—THE SPECTROSCOPE—It has often occurred to me that some of our numerous brethren who practise with the spectroscope might, if they were asked, give ива paper or two concerning the practical working of the ln«trumenL Aud if anyone bas made one of thoie Instrumente at a cheaper rate than paid for at an optician's (of course It Is not the elaborate construction of the instrument but its efficient working when completed , perhaps he will give a description and probable cost M making the same. If any will do thus I think he «ill receive the hearty thanks of many others besides myself. —A. J.jarman.
[2562.]—MOIST COLOUR4.—Could any of your kind renders inform me how to m»ke moist colours or cakes of paint, like Winsor and Newwn's?—ORANGE.
[4553 ]—TUNING CONCERTINA,—Will any reador lnform me how to tone English concertina reeds, and lbbest kind of metal? What I want to know most Is the tuning after the metal is screwed In.—W. B.
[2551.]—SQUARE GASKETINO.—H-w«haU I proceed to plait gasketting or spun yarn to form a solid square, аз used in stuffing-box of engines.—LrrtLB Charley.
[2*58] — KCl 10—Will any reader kindly inform me bow Hie echo is produced with tho cornet?—An Ayrshire Amateur.
[SS56 ]—ENAMEL.—I bave tried the rocipe for maklM white enamel that "Iuta "kiudlygaveoupage Is, bul I find it will not keep together: if" Iota" or some other breUMi reader will tell me the reason why, and the remedy, he will greatly oblige.—A Burner. [■-'057.]—COPPER COIN.—Could any of your correspon
[25Î.5.]—CONTENTS OF PART OF SPHERE.— Will воте brother render inform me how to find the content of part of a sphere greater or less tban a ,'. the two plane surfaces at right angles ?—Anthony.
[2526.]— SUBMARINE LAMP.—I have made several fruitless efforts to make a lamp some 3in. diameter by 5 or б long, that will burn under water. Conld you get me any information on the subject ? I want it to burn when submerged some 4 to 6ft. in freah or Bait water. 1 havo tried a caudle in a lamp fed with air by india-rubber tubing, but it went out speedily. Information as to the construe tion of such a lamp would oblige.—W. A. Hackett.
[2527.]—ROSCOE'S LUBRICATOR.—Will some one of our practical correspondents kindly inform me whether Roscoe'e patent lubricator lubricates the slide-valves of a locomotive engine when the engine is running with steaui on, or only when the steam is Bhut off ?—G. W. R
[2518.]—MUSICAL BOX.—Would some kind and competent reader give a Tull description of a musical-box? 1 would be particularly obliged if some one would tell me how the uniform motion is obtained—Omar.
[2529.]—INVENTOR OF THE MANGANESE BATTERY.—Will "Mr. W. H. Stone," who gave a description of the manganese battery, state the name of tho inventor of the вате ?—X. Y. Z.
—THOMSON'S ROAD STEAMER.—The асСО mt in jour paper of Thomson's road steamer is sur
gramnie. Is this not an error V—Calculator.
—SMOKE ON WALLS.—I beg to submit the following o_nestlon to the investigation of the scientific correspondents of our E. M. 1 observe that, in a kitchen or any other placo of which the walls havo been whitewashed, the Btnoke Is deposited on the whole t-urface o: the walls and ceiling, with exception of the edges or intersection«. What may be the reason of this? Are there a: those places currents which prevent the deposition, or ithis phenomenon of the same order as the one that is observed with tho iodine vapours in presence of a relief or of an engraving?—V. M. Beecht.
2541.]—GALVANIC BATPERIES. — I have beer. Btudyiug for seme time past the problem how to statte an economical, constant, energetic, and lasting battery. I triod many substances, and heard afterwards thai several hod been already triod and had failed; might it not prove very useful to many readers lo have a list of all the substances proposed or tried, with the resulta? Tbii would spare much lime and prevent wasto: many readers could bring their brick to the building besides learned "Sigma," who has promised. I believe, lo give us a not»? •• On Batteries."—V. M. Beeoht.
pS42.]-PHOTOS. OF AUSTRALIAN SCENERY. —Would any kind brother reader toll me whore I can procure photographs of on Eucalypt tree, and or un Australian acacia, or of an Australian landscape wi'.n those treee?—Bernardin.
Tke Insldeof (he cutting Is beautifully polished, and T toYT> been told that the secret of polishing the cu«rnvIdi i* lout; is thin Bo? Perhaps »omo ol your readers. •rem collectors." would Vindly Inform roe. or give me «iy hint wliereky I coald judge if the cutting 1« an utlique or a modern one ?—Vivis Sph:vmhm
ri!WM.]—MICROSCOPIC —I should feel under obllitlon to your microscopical readers wh« would inform mo what is the view of first-class observers as to the lenses in the compound eyes of insects—the tlraaon-fly for instance. Do they consider the hexa•'r)»"al piece is all lens, orth.it a minuter circular lens is "fixed in this hexagonal seitlnpr.»—F. F.
[2501.]—BOOKS —' should be glad Is rcadlajf of the •rtie* of books to be able to know exactly what Is meant, as I am neither in the trade nor otherwise able to learn. My requirements are the sizes in Inches of the page of all from imperial 4to to Umo ?— F. F.
r2MS.]-HARM0MUM.—I Intend to make a harmonium pan according to " Kleve's" instructions to a •■ Country Amateur, ' No. 245, page 279. but there are one or two things I should like to know before I begin, that 18, the size of the reed hibs in the veneer at top and bottom, and also if the veneer is the very thin kind that is sold in the shops? I should think that the reed veneer at least would raqulre some thickness in order that the reeds may be screwed to It Perhaps M Eleve " would be so kind as to enlighten me on the subject. I would also take it very kindly if some of ryour harmonium correspondents would show mo the way how two or more rows of reeds are placed In a harmonium—how the channels are connected with one another? I may mention that I have an apparatus under the keys of my harmonium by means of which a tune in any key may be played on the white keys alone, except where an accident occurs, wheu the Mack la uaed. This is done bv merely shifting a small knob in front of the key-board, according to the key to be played upon. Perhaps some of your musical correspondents would say whether It is an improvement or not. It must be an advantage to those wh« would like to play a common tune in as easy a manner as possible, who are not very well versed in the mysteries of sharps or flats, as by this a tune in four or five sharps or flats is as easy to play as oue in the key of
[Sjfii.J-SMALL COPPER COfX.—Obv., a shield of arms, " A fialfe Penny, lortR ;" rev., two men holding a piece of cloth, " For the Poor of Dover.'1 Why was it struck, aad by whom ?—Old Com.
rMM.l-LEADEN COIN 8IZBJ OF A HALFPENNY.—Oa one side a rude "\V," on the other a device probably Intended for an anchor. Should like information about it .'—old Coiir.
fSSta.'—HERBAL OF THE BIBLE.—Will any reader of the MtniAKic tell me of a book frosting of the plants named in the Rtble ?—txiort.
12596]— TOOTH POWDER.—Will some brother subscriber kindly give a good resipe for a tooth powder ?—Inquirer.
l-ax.lr-CHIMING CLOCK.—I have a chiming clock, the weights of which are so heavy (281b. eachl that whenever a line breaks, the weight, falling from a height of perhaps Oft, has an unpleasant way of breaking through the floor. Can any reader suggest any means by which this may bo prevented 1 I have thought ot a bag tilled with hay, or something similar, to be placed at the bottom ot the clock-case, and so act as.a buffer. In that case, what wonld be the bust material to stuff the bag with ?—Toodles.
[J5&S.]—HARD WATER.—I And the Thames water ■ ■ soft, but that the same water when it has passed through the water works gets hard. How has this change been brought about? Cau anyone explain the mystery ?—Steadv H And.
[SWiu.i—BAT HANDLES.—Can any of my brother subscribers tell me how to prepare aud glue up bat handles?—«5, Vol. 4.
[2.W..]-GLAZ1E8V DIAMOND.—Will any subscriber inform nvi h"w to soften the metal for taking out glaziers' diamonds; also, what metal is us>d, and how to re-fix the diamond ?—Ignorance.
^n.j-MATHEMATICAL TABLES.—Will any kind friend inform me in which of the modern cycloptedlas is tae best and fullest account given 01 the mathematical tables published to the present time.— W. H., Clnderford.
[2*72.]—LARUE FILTER—Would some person of experience advise me about a filter? I require about ">Oi'0 gallons of clean water every 24 hours. My water carries a considerable quantity of sand, insects, vegetable matter, Ac., and Is often during the day quite turbid. Could I construct a Alter, using a largo treacle or other cask in the manner described on page 578, Vol X? Would "W. II U.", (111, Vol. X., tell me where he got his "moulded enrbon filter blocks "? Would common wood chnrcoal answer?—Hydro.
[2573.]—A:olian HARP.-Would someone tell me the best way to make an .Koliun harp; also the best n ateriali for same? A small drawing with measurements for one to tit in a common window sill would help me very ranch.-K B
(25741-BRONZING MODEL VESSEL. — I am making a small model vessel, which I wish to bronze in imitation of capper oa the bottom, and I want to know If the best copal varnish put on will cause the l.ronze to stick; if not, what will I—O.vE IN THE Dark.
PWSO-GBTTAPERCHA v. ROPE BANDS.—Will nny machine worker tell me which bands work best— ^•utta pc-cha or hemp rope, and which do their work (.est? I believe rope is allected by the damp or dry weather—I mean round bauds.—Sussex.
PS9T8.J—IWBUMATIC PARADOX.- Could any of cur Ingenious readers give Tie an explanation of the action of this little instrument/-swansea.
PSS77 J—HORING O'LA.SS.-Can auy of my fellowreaders inform me how to cut a hole. -in. in diam., in the centre of a common piece of glass ?—C. H.
[asTS.]—CONTACT BREAKER.-Will "Tangent' kindly say where I can parciua one of Khnmkorff's' double quicksilver cout ict breakers, mid at what price! Are they dlllicnli to make?—Thomas J < i Connor.
THE SIZE OF ATOMS.—Sir William Thomson, *rho contribute* an important paper on the "Size of Atoms " to last week's Xature, thus sums up :—'* The four lines of argument which I nave indicated lead all to substantially the same estimate of tho dimensions of molecular structure. Jointly they establish, with what we cannot but regard as a Tory high decree of probability, the conclusion that inany •rdinary liquid, transparent solid, or seemingly opaque-solid, the mean distance between the centres of contiguous molecules Is less than the huudred-millionth, and greater tbau the two thousand-millionth, of a centimetre. To form some cocception of the degree ot coarse grainednesa indicated by this conclusion, imagine a raiudrop, or a globe of glass as big as a pea, to be magnified up to the •size of the earth, each constituent molecule to be magnified in the same proportion. 'J he magnified structure would be coarser grained than a heap of small phat, but probability less coarse grained than a heap of cricket-balls."
THE COLOURING MATTER OF BLOOD.-Herr
Hoppe-Seyler of Tubingen, who baa for a considerable time been investigating the colouring matter of the blood, and has discovered that tfie socalled Hicmalin is an essential product of its decomposition, frhows that this substance is a product of oxidation formed immediately on contact with the air; and, that, mo.eover, by decomposition of the colouring matter of the blood, a'nother substance, besides albumen, results, which he calls Haemocliromogeu. Both have peculiar effect a upon light, which can be recognised by the absorption-bands in the spectrum, and enables them to be distinguished. Both contain Iron.
THE LATEST EXCAVATIONS IN POMPEII, Ac—The Giornale fit Sapoli, of March 26, states that on the occasion of a royal visit to Pompeii on the preceding day, some excavations were made in some houses situated on the right of the Via Stabiana, and a variety of treasures were fouad, viz.: a large number of objects in terra cottn, iron, and bronze, a beautifully-chiselled silver cup, a very rare glass oil lamp, a still rarer and perhapa unique object, consisting of a small terra cotta cup with a metallic cup inside containing a night-tamp like those in modern use, a large gladiator's sword, with the metallic portions oi the neabbard; many copper and silver coins of the time of Vespasian, aud an amphora full of small onions near the skeleton of a woman. The skeleton of a man was also discovered, holding a pickaxe in one hand, au iron bar in the other, and with many bronze objects scattered at his feet, near a wall which had been partially broken through.
THE LONDON CO-OPERATIVE WATCH MANUFACTURING COMPANY—On Monday night illth loatj a crowded meeting of the workmen engaged in the various branches of the cluck and watchmaking trade in Clcrkenwell waa held at the Amwell-strect School-room, Pentonvillc, for the purpose of considering the advisability of tho trade, as a body, supporting the above company, established by operative watchmakers to promote the production of genuine Loudon work. Mr. C- Young, who occupied the chair, opened the proceedings by declaring his conviction that the only way to retrieve the present depressed state of the trade, owing to the large Importation of foreign watches duty free, was by the workmen combiniug together in a co-operative company to produce a watch equal in every respect t« the best foreign watches imported, and at as low a price. There were three points upon which he believed there was no difference of opinion—viz., that if the watchmaking trade Whb to be kept in this country, the whole system of production must be changed; that watches should be ol'one unitnrm gauge ; and that all foreigu watches sold in England should bave the maker's uame, and thus prevent them being palmed off on the public by unprincipled sellers an English lever watches. Tho meeting was then addressed by Mr. Ganney, who deBt'iibed ttc system of watchmaking by machinery as practiced in America. It was acknowledged by all that the Clcrkenwell warchmakers were the be?t workmen in the world, and the company were prepared to supply a silver levers-plate watch, juwelled iu four holes, for 50s. This watch had been designed and produced by a committee, composed of the very best workmen fu every branch of the trade, .aud every part of the watch would be made iu one building, thus effecting a great saving in lime and expense upon the present system. Messrs. Newton, Iloldsworth. June*, llislop. Mead, and others addressed the meetiug in support of its objects, and the following resolutions were curried by large majorities:—" That' in the opinion of this meeting the nuion of labour and capital under a well-organised system of co-operatinn is es-enttal to the maintenance of the watch trade in < lerkenwell." "That watches should be made by a uniform gauge, and that every watch should bear the muker s name." "That this meeting pledges itself to
support the London and Clcrkenwell Operative Watchmakers* Manufacturing Company." Several objections to the scheme having been replied to, to the apparent satisfaction of the meeting, the proeeedidgs coucluded with a vote of thank* to the chairman.
A STEAM-ENGINE WITHOUT A CRANK — The Milwaukee Dotty Sew* thus describes the performance ol an engine, which, however, we fear our readers will read with considerable doubt. The engine is very simple, aud consists of a cylinder 12in. lohg and GJin. bore (in one already built,), with the shaft passing through the centre of ft. The cylinder is (urnished with a piston at each end, precisely like the pistons of common crank engines ; to these pistons are connected short rods, with a friction roller at tho outside end working in the laside of an elliptical ring, which passes around the shaft outside of the cylinder; outside of the ellipse is another friction roller, connected to the piston by compensation lever* In auch a manner that when the pistons are moving towards the cylinder, the rollers act on opposite sides of the ellipse, both pulling directly towards tho centre, thus causing them to move forward on the ellipse, and communicating a rotary motion to the shaft. After the rollers have passed forward to the shortest diameter of the ellipse, the steam Is exhausted from the ends of the cylinder and let into the middle, between the pistons, pressing them outward, causing the rollers in tho ends of the piston rods to act on the inside of the ellipse, aud coutinuing the forward motion of the shaft until they arrive at the long diameter, when tho steam is exhausted from the middle of the cylinder, audjis again applied at the ends. The results obtained were surprising, and can hardly be credited by believers in the infallibility of the crank motion. The cylinder is about thesizeof the cylinder of as eight-horBO crank engine, with a stroke of 31n. for each piston, and the power evolved was at least .'.'-|;(ii>i- power, and some present at the trial placed it as high as 2d-horse power, with a speed oi 100 revolutions per luinue, and 501b of steam, consuming about the amount of fuel required for a 10horse engine.
THE PULSE.—Dr. Omanza describes a method of registering photographically, the beats of the pulse. The appartus essentially consists of a siuull inverted funnel, having along narrow stem and a caoutchouc base. This iuatrument is filled with mercury to a certain distance and its base Is applied to the heart or an artery ; the oscillations of the mercurial column are then photographed by well-known processes. It is said that with this apparatus the apparently single stroke of the pulse is shown to coasist of three, or even four, in succession.
DIMINUTION OF WEIGHT IN MAN DURING THE COLD MONTHS.—Mr. Milner, of Wakefield (Am. Jour, of Med. RritnM), aome years since performed a series of experiments with a view of determining the periodical fluctuations in weight, substance, aud form, which the whole body undergoes. He weighed every prisoner upon his entrance into the convictestaMtshment at Wakefield, and subsequently at the end of every calendar month, all of them being subjected to simitar conditions of temperature, food, exercise, and ventilation. The number of men weighed exceeded 4000, and the total number of individual weighings was 44,00-i. From his experiments it was found that there was a progressive tola of weight in January, February, and March, and a gain in April, May, -June, July, and August, and a los* in September, October, November, and December; or, in other words, an increase of weight during he hot months, aud a diminution during the cold. These results are in accordance with physiological truth, for Dr. K. Smith has shown that the quantity of carbonic acid exhaled in winter is largely in excess of that given out iu*summer, and the sudden weight iu April is found to correspond with an equallyabrupt diminution in the quantity of carbonic acid expired.
UNIVERSAL STANDARD OF MEASURE MENT.—According to the Memorial Diplumatiqtte the Austrian Government has just signified its ass en to a proposal of the French Government for an Inte rnatlonal Commission to assemble in Paris in order t^ aitree upon a common standard of measurement for alt civilised nations. Already 15 European Powers have announced their willingness to take part In the commission. Even England, which hitherto has been disinclined to depart from old customs, will be represented by the Directors of the Observatories of Greenwich and Oxford. Tho French Government now only awaits replies from the United States, Brazil, and the South American Republics previously to calling together the commission. The Minister of Foreign Affairs would of right be the houorary president, but the proceedings will realty be directed by the vicepresident, General Morin, Director of the Conservatoire des Arts et Metiers, in whosa archives is deposited the official standard of the metre recognised in France.
A CURIOUS DISCOVE RY.—Dr. Milio, the celebrated surgeon of KicfT, has recently been at St. Petersburg explaining a means he has invented of illuminating thabody by means of the electric light to such au extent that the working of the human machine may be observed, almost as if skin and flesh were transparent. The Moscow\Gazt'tt<- asserts tsiat, to demonstrate the feasibility of his process. Dr. Millo placed a bullet inside his mouth and theulighted up his face, upon which the bullet became distinctly visible through his cheek Dr. Millo does not propose to lay bare all the secrets of the flesh, to explore the recesses of the heart, or to perform any miracles, phyBicnl or metaphysical But heclaims to have discovered a new and effective way of dealing1 with gun-shot wounds; first, by means of electric illumlnatijn he discovers the precise situation <jf the bullet: next, by means of magnetism, he proposes toextract ^he bullet — provided always that the bu'letcoutain some portion ot steel. Against leaden bullets his system is powerless, and he therefore intends to represent to the International Committee, which lately met at Geneva, the desirability of recommending an admixture of steel in the manufacture of all future bullets. Dr Milio's experiments with bullets containing only a flight admixture of steel are said to have been t loroughly successful.
ANSWERS TO CORRESPONDENTS.
* • Al] communications should be addressed to the Editor of the English Mechanic, 31, Tavmtockjtreet, Covent Garden, "ff-C.
ENGLISH MECHANIC MUTUAL IMPROVEMENT SOCIETIES. Last week we inserted a letter (p. 89) from Mr. D. William Kemp, of Leith.oH the formation of "english Mechanic Mutual Improvement Societies." The ideáis a good one; in fact, it is in harmony with the structural idea and purpose of this publication under its present management. Our readers and subscribers feel an interest and a pleasure in mutually instructing each other. This they now do through tlw posT. Mr. Kemp suggests that they should also meet together in different localities, cultivate each other's acquaintanceship, and "discuss some of the topics reviewed in the Mechanic during the past month." The suggestif has already taken root. It will be seen hy an advertisement in our first page that a meeting of the subscribers of our journal in Edinburgh is called for the 29th inst., at the New Waverley Hotel. The experiment is a novel one, and we trust it will be successful. We shall be glad to record the result.
A. Moréis —On page 87, under the heading "China Grass."
Painful.— Your disorder would seem from your description tn he some neuralgic affection; hut it would be exceedingly unsafe to advise. Consult a medical man.
il'MANE Man.-- It is a question we cannot well treat of in these pages. Tell your friend to discontinue his evil practices at once, or he will die early or become insane. He has debuta ted his constitntion by vice; he can only restore it—or partially restore it—by virtue.
J.AM4S Bkll IJouzlas, Isle of Man, writes us that he does not agree with M. Somner's opinion "n the cause nf sleep. J. B. says. "My opinion is that the heart continues to strike less the pericardium when the person continu« a to sit or rest; hence the constant current of blood which flows from the heart is not so strong." We opine" J. B.'s" opinion is conclusive.
W. H. Goss.—The numbers were forwarded. Wc cannot be responsible for postal irregularities.
Тнк Выск рвом Liverpool.—Not the sert asked for: the shapeof the parcel betrayed its contents. We returned it to the railway company unopened without paying the carriage.
THE ENGLISH MECHANIC LIFE-BOAT
Subscriptions to be forwarded to the Editor, at 31, Tavistock* street, Covent-garden, W.C.
The following are the initials, &c., of letters received up to
first post, Thursday, April 14:—
B. Förster, J. M. Proctor, W. W., R, M., J. H.( Rev. IT. E. G., W. H. C, Capt. Fawcett, W. II. В., Rev. N. W. G., Rev. G. B. G., Т. C. and Sons, Rev. E. K., J. Crowther, 1). W. K., S. 8., E. A. K., J. A. Watt, J. P. J., У. King, Y. W.T., B. Edwards, J. A. M., J. A. B: and Co., F. A. M. D., J. II. and Co., J. R. Williams, W. B. II., H. H., A. Granville, J. fl., E. W. H., W. A. II-, W. II. G., R. К. H., G. R. M., L. and Co., C. Paget, П. C. C.t Geo. Luff, С. В. A-, Veritas, H. E. G. G. Firth, Casual Observer, Hugo, West Indian, W. Stephenson, Swansea, Auti Egyptian, W. В., С Uolday, A Smoker.
J. E. Costard.—No. 124, Newgate-street. See our advertisement pages. Cicero.— Beginners do not get £100 per annum in the Bank of EuglamT Your other queries would take up too much space. S. W.—Results prove you wrong. Lambda.—We know of no institution in which Greek is
taught conversationally. Inquirer.—Under the circumstances it would he waste of money for В to patent his invention if it were covered by A's previous patent. We can, however, scarcely give reliable advice as to the course to be pursued with only your general statement to found our opiniou on, and should advite you to consult some respectable patent agent. Bat Hagan is more than half a fool. T.S. Reynard.—No stamps enclosed. >'orthijiDRiA.—We could not in any case consent to "exchange" articles sent through our office.. We know nothing as to the respectability of the Exchange Mart alluded to. W. Boyd,—The inventor of the pedespeed is an American. Thanks.—"Carthusian" thanks Alexander Hall for the trouble be has taken with the "distance measurer." He th:flksit, however, too complicated to be constructed by any but a regular watchmaker. J. L. Т.—Write to the Secretary ïl the Institute of Surveyors,
12, Great George-street, Westminster. W. H. W,—Queries really too insignificant. A Wksthbad.—Wcdon't know the address. Flint.—Third brass Roman coin of Maximinus. It. J. Stubbs.—Consult some respectable optician. Your
query is an advertisement. W. R.—It is fruitless to kick against the pricks. J. В.—We don't answer by post.
Phrenology And Big Heads.—"Saul Ryraea " has sent us a long letter exposing the fallacies of "Т. D.'s" letter in our last number. The insertion of the letter would lead to a fruitless controversy; at all events we think our space may be better appropriated. Our experience teaches us big heads are no guarantees or even indications that their possessors are wise men. C. V,—No charge is made for queries. J. II.—Don't ask such silly questions.
Alfred Allen. — We shall bye-and-bye have a halfpenny post for newspapers. The English Mechanic ought to reach von before Saturday by the ordinary trade channels. The Earth's Motion.—Mr. Beardaley says :—" Will you kindly alter the heading to my letters on the 'Figure and Motions of the Kart h ' to ' The Earth—Its Reputed Figure and Motions r" I make this request as it is more in keeping with the spirit of the contents of those letters, and is in otlier ways also more applicable."—Mr. Beardslcy is quite welcome to the change of title if if will do him or his cause any benefit. We think it right, however, to say that the reason why we have pmced at his[disposaI a certaiu amount of space is that some one may have an opportunity of refuting his fallacies-fallacies which are being enunciated nightly by Parallaxes, enthusiasts, and charlatans. Perhaps Mr. J. Dyer, the author of the admirable little work "Spherical Form of the Earth," noticed by us a few weeks since, will reply to Mr. Beardaley? Ignoramuses.—"Pitman's system, which is the best, can be learnt from Мз manuals, which are published at cheap rates. We give the preference todrawing, because a knowledge of that art is absolutely necesssary to the great majority of our readers, while shorthand oould only be useful to s few. We must advise you to become more perfect in spelling and composition before attempting phonography. Lena.—Search at the Patent Office.
Plkbeian.—1. Prices of globes vary; inquire of the makers. '¿. By tracing its position on a map or globe. 3. We do not know. J. Byng.—It is a Parisian invention, and is patented in England/but whether manufactured or not we canuot tell. Search at the Patent Office for the specification, and write to the inventor or his agent. We do not reply by letter. Тле Sixpenny Sali: Column is the only place in which can appear q leries forwarded by A. E. Tucker, " One iu the Dark," " Sussex" (2nd query). Derby, A. O. Z.—Search at the Patent Office. Gkorge Gaskell.— Both your queries have been answered —
lbi* Iw'ter very rrcently. So, Vol 4.— Buy one of uur rases.
Amount previously acknowledged £164 18 10
W. H. Thorp 0 10
Per E. Hurst—
Proceeds of a concert given in aid of the
English Mechanic Life-Boat Fund, at
Head Quarters of the 1st Essex Engineer
Volunteers, Hey bridge, near Maiden, Essex;
and promoted by Messrs. Mulley, Andrews,
and Hurst, in the employ of K. If. Bentall,
Esq., MP., Heybridge Iron Works.
Collected at the King's Arms Hotel, Kensington, by H. Cowan—
А. В. P
Mr. Andrew ...
E. J. В
169 19 4
1Q24 L. A. Brode, Glasgow, fibre suitable fur making paper Wirt a brown col л urine matter
102-1 C. H. Gardner, West Harding-street, Ketter-Isne. 1лпdmi. improvement in typographic, lithographie, And zincogrHpliic printing machines
MM C. Montague, Cannon-street. London. Improvement 1л the manufacture of overcoats and other garments
Ш7 J. Shackleton. Bradford, York, improvements in apparatus for heating or warming room*
10M T. Robinson, Widne*. apparatus for skimming coat iron during the process of casting
1029 0. Clinch. Witney, apparu tu* for" cleansing" beer other fermentable liquids
1080 E. Daniel. Rape-aumfttown. near Rouen, apparaît? indicating the water level in steam boilers
lost P. Taylor, Manchester, improvements in the construe*-! tion of paper оойагв
1033 A. Watklus, 496. Strand, and R. Cory Hanrott. 5. Orayainn-square. apparatus for winding and setting watches
1033 J. Edmond «on. W. Edmonson, and F. W. Edmonson Manchester; improvements in machinery for etching or eugraving cylinders
insi W. H. Canton- and J. V. Toone, Warminster. Improve Л automatic lamp-creep
1033 H. J. Kirkmau. 3. Soho-square, improvements in tbo eo straction of pianofortes
1030 G Baker. Bridge-street, Norwich, improvements In themnnufucture of tacks
1037 T. Aveling. Rochester. Improvements in the construction of agricultural, road, traction, and portable steim engine*
1038 fl. P. Andersen, Abhey-wooer,- an improved apparatus to be used In window cleaning
1030 A. Etienne.Charlotte-street, Fitzroy«square, construction of carriages, vehicles, and velocipede«
1040 W. Cooper, Bradford, York, improvements In sliver or cotton cans
1041 J. B. Births. 8r. Marr-nxe, London, apparatus for ■«»soiling, injecting, and preserving wood
I0i2 J. Fatrclough, Warrington, an improved mill stone dress—A communication
n>« A.JCraig, 12.1 May-tcrraee. Renfrew, improvements in mills
10*4 C, F, Varley. Beckenham, improvements in electric telegraphs
1013 W. Nelson, Rolton, manufacture of quilts, toileting* and other figured fabrics
1046 H. Mallet and С Russell, New Bagford. twist lace machines
1017 W, E. Newton, ce. Chancery-lane, Improved machinery applicable for inland navigation—A communication
1018 A. H. Brandon, 13, Rue Gallion, Paris, improvements in looms—A communication
1040 A. Mosley. Old Radford, improvements in the jacquard" 1050 P. O. Thamsen. Copenhagen, improvement* in finishing linen, cotton, and other fabric?—A communication
1031 J. Henderson, New York, an improvement in the manufacture of wrought iron and steel
1062 W. R. Lake. Southampton-buildings. London. Improvements in the construction of steam vessels—A communication
1053 A. Parkes, Birmingham, improvements in the manufacture of steel
1054 S. С Lister, Bradford, improvements in looms for wearing
1055 I.. Weber, 104. Rue Royale, Brussels, Improvements In galvanic cells and batteries
van G. H. Ellis. 01. ûraeechure h -street, Improvements in rotary engine» and pumps
10&7 W. Higgins, |1, Gnat New-street. IFetter-lane. Middlesex, improvements in the manufacture of hackney carriage' and other lamps .
1036 A. Brown, Lanark, improvements in ornamenting wood, leather, nnd other materials
1050 J. B. Booth, Preston. Improvements in apparatus for lubricating and covering spindle« employed preparing, spinning, doubling, and winding nhrous materials
1000 R. Adams, ia, tïla'istoue-teriuce, Battersea-park, improvements in spring binges
1001 T. J. Srrith. )*# Fleet-street, improvements In treating; excremental matters—A commuuication
lis obedience to the suggestions of a number of readers, we ha^e decided on appropriating a portion of our space to a condensed Hat of pateuts as nearly as possible up to the date of our issue.
APPLICATIONS FOR LETTERS PATENT PURINQ TUB WEEK ENDING APRIL 12,1870.
989 J. Winter. Ward our-street, Soho, apparatus for filling glass bottles and jars with soups, Jellies, ar.d other edibles
090 H. W. Hammond. Manchester, improvements in the manufacture of iron
991 H. A. Dufrené. M, Rue de la Fidélité", Paris, improved machine for winding yarns or threads on bobbins—A communication
90-2 T. Smith, Leigh, looms for weaving
993 J. Pickup, Tong, York, improvements in machinery to be employed In drawing, spinning, and twisting fibres
904 A. M. Clark. Chancery-lane, Improvements in apparatus for washing and treating pulps— A, communication
995 .1. Pickering, Glasgow, forming holes in iron castings
999 J, More, and W. L. G. Wright, Glasgow, apparatus for forcing and projecting liquids
007 TTRose, Oxton, and R. Emerson Gibson, New Brighton, utilisation of a certain material obtained In treating cotton seed
998 O. J. Busk. Pancras-lane. London, treating cements for the purpose of rendering them applicable for the production of nrtlfloial stone—A communication
909 P.. Green. Phoenix Works, Wakefield, apparatus for removing soot from the tubes of steam boilers
1000 J. Parker, Woodstock, improvements in dry earth closets
1001 Б. Lever, Haug<Mon, improvements in signals and name plates tobe used with letterboxes
1003 J. McNaught and W. McNaught, St George's Foundry. Roclidnle. steam boiler furnaces
1003 P. M. Childs, it), Mark-lane, Loudon, improvements in sash fasteners—A communication
1004 T. Horrldge, Bolton, means of communicating between the passengers andgiiurd
1005 T. Kord. Birmingham, improvements in gas lamps
1000 I. Baggs, High Holborn, improvements in making car* nonatos of ammonia
1007 E.J. Hill, Victoria Railway Station, Pimllco. slipping and depositing parcels and packages or other objects
1008 A. H. Brandon. 13, Rue Gallion, Paris, an Improved strap fastener—A communication
1009 R. Jones, Uotoiph-lane, London, merchant, improvements In the preservation of animal and vegetable substances to be used as food
loio J. Mayer, 59, Great Portland-street, improvements in specula for surgical purposes
1011 J.Sharrock, Rochdale, improvements applicable to winding engines
1012 V. J. Sweeting. Clyde Dry Dock. Rothorhithe, apparatus for indicating the distance travelled by vehicles
1013 G. H. James and J. James, II, Newgate-street, improvements in cases for cigars
1014 W. Young, Magdalen-bridge. Midlothian, and Г. Brash, Leith, manufacture of illuminating gas
1015 C. H. Wight, Baltimore, U.S.. improved inkstand
1010 С. H. Wight, Baltimore, U.S., an improved stand for containing stationery, in combination with a thermometer
1017 W Henley end D. Spill, North Woolwich, non-explosive compounds forming the material for the manufacture uf collodion
lois A, B. Brown. Birkenhead, improvements in steering
Sear, and in machinery for starting, stopping, and reversing eavy steam engines
1010 M.J. Roberta, Pendarren, near Criokhowell, Brecon, propelling apparatus for »hips and other vessels
1«0 U. Croseley and R- Whipp. Manchester, and T. Crosslcy, Rochdale, Improvements in the manufacture of size
ЮЛ T. Adams, 14. Little Tower-street, London, stationer, a spring clip tile or binder—A communication
Kris T. Adams, II. Little Tower-etreet, London, binding music, pamphlet*, and o'her papers—A communication
loJ?. H. л. Bonneville, 18.Cliaussce d'Aiilin. Pans, astronomical instrument called the " Helutde'-—A communication
293« W. Kelsey, improvements in drivingdrums or pulley» Z937 D- Sowden and R. 0. Stephenson, improvements in loom» for weaving , , ,
2951 G. A. Middlemiss, Sunderland, apparatus for withdrawing water or other fluids in as pure a condition as po**ibJo from wells, cisterns, and other places 2950 E. A. Snuggs. improvements in cocks, taps, and valves KfiO R. L. Hattersley. improvements in looms for wearing 2962 J, B. Blyth. Improvements in the mode oí »ad apparatus for vaporising and burning liquid hydro-carbons for the production of beat in furnaces ana for generating steam
2ÍW5 E. Farrington. improvements in breecu-loading firearms -...*. 2970 J. H. Relwyn, improvements in fire-arms, parts of which are applicable for use as a digging tool
2977 a. Osborn, improvements for reaping and mowing machines
2980 J. Hartley, apparatus for registering billiards or other games
2981 R. J. Ellis, improvements in apparatus for deaiccatmg animal and vegetable matters
299i J. Hudson. J. НшЬоп, and C. Hudson, improvements in mnchinery for the manuiacture of paper
3079 W, J. Rivington. improvements in counting and registering apparatns
»<i*i С v. Abel, anew or Improved manufacture of metal мtiles or elates for roofing
3006 G.tlrelnnd, improvements in nutcrackers!
3253 J. Mason, an Improvement or improvements In metallic pens
8557 w. Tranter, improvements in fire arms
1Г8 С A. Calvert, an improved apparatus for self-rejist<rini and checking the money taken for admissions to publie entertainments
«m F. T. Ferguson, an improved iug or pitcher
2972 L. M. Caselia, apparatus to be employed in lighting gas burners
2973 R. Scholefield, improvements in pumps or apparatus for raising or forcing water or other liquids or fluids
2982 W.J. Bon ser. apparatus to be used for feeding and watering cattle iu railway trucks
2989 L. A. besage, improvements in closing and securing vessots containing alimentary substances
3007 S. Barber, apparatus for the propulsion and steering of~ navigable vessels
3013 W. E. Gedge, an Improved elastic horse shoe
3023 W. H. H. McNeight, Venetian and other blinds
3057 J. F. Crease, an improved method of attaching cementa
to Iron or other sabstanccs
3059 W. Firth, wheels of traction carriages lor use on common roads and tramway« 3071 F. Jenkin, improvement« In bridges 8078 J. Rignall, improvements in reaping machines 3119 W. A, Ross, improvement« In preserving the surface of
iron, steel, copper, brass, and other metals 315П R. Marsden, pulley blocks or apparatus for raising heavy
weights 3159 A. Minton, improvements in electro coating Iron sod
other metals 3100 b\ de I agitlardale, producing condensations and eva;o
ratlons in vacuum 8247 J. P. Budd, improvements in the manufacture of Iff-« 3708 R. Derbam, an improved machine or apparaiai Tut
washing potatoes 8778 J. A. Johnson, improvements iuthe manufacture of iron
nnd et*>el—A communication 153 J. H. Johnson, improvements In the treatment оГ »cid
tars obtained from boghead, mineral schist, vr petroJ»am-A
communication 302 H. M. Whitehead, improvements in preparing block« пГ
animal and vegetable materials for making soup ur other
Liquid food 8U J, Hanson, improvements in breech-loading firearms 40i W. U. Lake, improvements tnlooma/ur weariug—A com*
m uní cation 570 A. vvtngard. *n Improved paddle-wheel for proprilin*
vessels in tue water
THF. НОТАХ, MICROSCOPICAL SOCIETY. THE ANNUAL SOIREE.
ON Wednesday, the 20th inst., while nearly all London was intent npon what it conceited to be great things, a select company of sa^e gentlemen were equally intent npon the • malle? t of small things, in the precincts of King's College. At an early hour on that day the secretaries ar.d chief members of the Royal Microscopical Society were at full preparatory work in their rooms. Cabs arrived every half-hour laden with microscopes, and the great »tirants were hastening aboot, some with coate off, placing and numbering the instruments. Several hundreds pounds' worth cf microscopes arrived during the morning, and it was no slight proof of public scientific spirit that all them were delivered and located without difficulty and without expense. Our own bumble microscope gained its place amidst a crowd of flaunting competitors which were gloriously bright in highly polished brass, and beautiful in appearance, but not a whit more useful for all practical microscopic science. A rich man may readily spend £120 with Mr. Ens» for a first-class instrument, but we are confident that our own, at a cost of abont £20, will do at much and as good work, though less to look at aod lighter to пюте.
On this occasion, for the first time since its establishment, the Royal Microscopical Society attempted to inaugurate anew style of exhibition, Hitherto these displays have been of a very misслЛ1апеопв and heterogeneous character. The several makers of microscopes had seized the freely-aceorded opportunity of showing their craft and skill to the great risiiing pnblic, and, Id truth, the annual soirees have been theatres for the performances of Megera. Ross, Smith and Beck, Powell »nd Leafand, Swift, Baker, Crouch, Murray and Heath, Stewart and Co., and other well-known makers. These soirees have really been manufacturers* bazaars, and greatly, it is understood, have they profited by them. During five or six of the latest of such displays the student will have observed many gradual improvement* in the form and in the accessories of the instrument, and will have noted each step in advance in concurrence with the year of exhibition. ■
Still this wajBot fulfilling the highest purposes
£. Microscopic science. It showed what was
profitable, but not always what was scientific. To
obtain resulte in the simplest and cheapest form
is the desideratum of the student; to show them
m the «Mtlier form is perhaps that of the maker,
not that the makers are without merit, for they
have met the spirit of discovery and research—
nor can they be blamed if tbey also look for a
The Royal Microscopical Society has gradually gathered, by bequests and by purchase, a very considerable number of objects, chiefly indeed by tïia. The late Dr. WaUich, Mr. Richard Beck, •od several others have given a most valuable •trie» of objecte to the Society, and the question h»t naturally arisen—how, and when, shall these be exhibited? No occasion can be во good as the amnui »tree. But, then, the instrument makers 7*т'.пем1т ,hnt ont tfae gentry of science. Well, ■th ^'=*ntr7 0I science, for once, claim space vntn themaker«; row such bas really been the re*nit. To« Microscopical Society resolved to display its treasures, and never did they come to a •worthier resolution. They printed a list of demrab/er object!, circulated it amongst the members, and thus contrived to offer a somewhat лоте systematic and really nsef ol exhibition than aforetime. It was less showy to ladies, but far more instructive to men. For the first time, in fact, the S'.iree has been less miscellaneous, and more truly illustrative of particular classes of olj cts.
ГЬсге was, indeed, no time for a leisurely study ci the rarious object, and those who had no pre
vious knowledge of them, of course failed to reap the full benefit of the display; but those who were acquainted with the elements of natural history and microscopy, and who came to see and not to be seen, found it possible to gain good results even in the heat, bustle, and jostling of the crowd of fair and unfair visitors. The makers of microscopes were there, and had their tables richly garnished as aforetime, with burnished brass and glaring lamps. They showed, too, many highly attractive objects, but little or nothing new to the advanced microscopist, thonçh much that was interesting to the passing gazer. But why should tbey make great efforts continually? They have had their day, or their nights, and all the microscopic-loving world has admired their craft and landed their ingenuity.
Amongst the objects shown by makers were some very fine sections of coal and coal-like fossil wood. We noted also a particularly fine Podura scale, shown by Beck and Beck, and a few fine objects under some instruments by Mr. Ross and by Mr. Swift The Society displayed a very *ood series of educational microscopes, with their prices attached, and beginners would be delighted to see such a series. The most straightened in means may be comforted by such a show ; for the small outlay of three, four, or five guineas a neat and useful little instrument may be had.
Dr. Carpenter was the lion of the evening, if the name of so large an animal is allowable in connexion with the smallest of creatures. On a raised platform at one end of the large room, he exhibited a very interesting series of objects from deep-sea dredgings. It is impossible to do any descriptive justice to them in a brief space—in fact, some considerable previous knowledge was necessary to appreciate them at their true valne. The wonder was not so much in the structure of a particular object as in its profound extraction. To gaze at little spindle-shaped "teste," or shelllike coverings, which were brought up from depths of 300, and 540, and 640 fathoms of seawater, was no slight pleasure; while to examine them in connection with the useful little descriptive catalogue printed by the Society, and also in the clever enlarged drawings overhead, was full of instruction and entertainment. One object, a small complete specimen of Orbitolltei was most attractive, for in it we studied the nucleus cf the disc formed by a spire of several turns, and the approach to a cyclical arrangement, showing that the whole subsequent growth takes its course on a cyclical plan. Then there were a series of CrittcllarUe, showing every gradation from the straight to the nautiloid form, which next to the Olobigerinee and Orbuliiue are the most common inhabitants of the abyssal waters. Beautifully constructed are their finely-tubular ehells, while under another microscope wae visible the animal itself of C'rittcUaria, which was obtained by dissolving the shell of a fresh specimen in dilute acid.
What could be a greater intellectual luxury than i his bringing up, as it were, from the silent abyss of waters, some of its choicest and tiniest inhabitants, into the very heart of noisy and populous London, and displaying them easily and pleasantly to the curious eye of every privileged visitor to King's College on this Spring night? Here were some 1200 sightseers ; many brought in commodious vehicles, all spared every kind of drudgery and dredging labour, provided with fine instrumental aids to observation, in every respect duly facilitated, and to crown all, with Dr. Carpenter himself at hand, ready to answer any intelligent questioner, and sufficiently tolerant even of the bore and the bungler. In the upperrooms were* the usual smaller displays, and relatively smaller, though by no means absolutely small, people of microscopio science. How pleasant on these occasions to meet old friends and ever to see old eights! On no account wonld we miss that amiable elderly enthusiast in polarised light, who though literally one of the "nation of shopkeepers," is a valued co-operator with the friends of his science. Ask him any question about polarised light, and you may count on a good and useful reply. Long may we live in light ! and and probably he would himself utter the prayer of one of the famous Homeric heroes, "Let "me die in light,"—if we ventured to ad4 one word to that prayer it would be "polarised."
To the great, tumultuous, busy, or idle world of London, snch sights as we have attempted to describe are unknown. Even the scientific world in other branches of study, scarcely know of their occurrence. Let us hope that the attention we have directed to them will bear fruits in a newly
awakened interest in microscopy, and au inquiry as to the society represented, and other kindred ones in London. One thing should strike every visitor to such a display as that of Wednesday night labt—viz., the amount of freely offered service devoted to the getting up and successful conduct of these soirees. Such service amply proves the zeal of truly scientific men, ar.d when we learn that previous days of careful attention are essential to the success of these exhibitions, we ought to be grateful to the officers and members of the Royal Microscopical Society, and to others on like occasions. May all these societies find many new friends, ample funds, and a thankful public to appreciate and applaud their zeal!
AND COLOUR BLINDNESS. By "omicron." TT is very evident to those who thoughtfully consider the earth as the residence of man, that the beneficent Creator has provided it not only with the materials that are essential to the existence of mankind, but He has provided much that only contributes to his enjoyment. He Ьач not only considered the needful, He has con sidered the beautiful. Enter the woods, and the ear is gratified by the songs of birds and the hum of insects; the eye is pleased by the thousand beauties of the landscape, and the variation of light and shade; all around is seen a tinted mats that speaks of the glory and goodness of the Creator. And among the various examples of the care bestowed by Providence on man, one of the most striking is the lovely mantle of colour that is everywhere spread round about him; and yet what man has long and commonly enjoyed, he often undervalues. To appreciate the full effect of this gorgeous robe of colour, it is neoessary to conceive a blind man suddenly restored to sight. With what pleasure would he welcome this new sense 1 With what delight would he drink in this new source of enjoyment! With what interest would he survey the scone before him, in its gay apparel! How long couldhe gaze upon the far-reaching expanse of lively green below him, and the calm deep azure above him without tiring of its loveliness. And after he had enjoyed the view of Nature in its marvellous assemblage of tints and colours, with what delight would he consider the details of the scene, how tenderly he would touch the flowers, and, above all, how thankful would he be in the possession of a sense which affords him such intense gratification 1 Very few value colour at its true worth ; and many often speak disparagingly of it, and consider other forms of beauty far preferable; and many speak slightingly, because They really do not appreciate it, and are not sensitive to any kind of beauty. "Such expressions," says Mr. Ruskin, "are nsed for the most part in thoughtlessness, and if such disparagers of colour, would only take the pains to imagine what the world and their own existence would become if the blue were taken from the sky, and the gold from the sunshine, and the verdure from the leaves, and the crimson from the blood, which io the life of man, the flueh from the cheek, the darkness from the eye, the radiance from the hair—if they could but see for an instant white human creatures living in a white world, they would soon feel what they owe to colour. The fact is, that of all God's gift« to the sight of man, colour is the holiest, the most divine, the most solema."
The investigation of the cause of colour has been attempted by several philosophers, though we oan give here little more than the names of the more celebrated. Among the ancients, the hypotheses to account for the phenomenon of colour are sufficiently vague, and colour blindness, or chromato-pseudopsis does not seem to have in any way engaged their attention. With the Pythagorean school, colour was the superficies of body; and Plato considered it as a flame issuing from bodies. Aristotle's notions were equally mysterious and inaccurate. After the long interval of the Dark Ages, when culture bepan to settle among the inhabitants of the West, modern philosophers promulgated their hypotheses. Des Cartes, the ingenious founder of the system of vortices, imagined colour to be a modification of light, and the difference of colour was produced by the rotatory motion of the particles that composod light. From this date all the students of physics connected colour with the phenomena of light, accounting for it by the rays of light entering tho eye at different angles with the optical axis. The experimente of Sir Isaac Newton, however, began a new era in the history of chromatics. By passing the eolar ray through » glass prism, it was plainly proved that light « us not homogeneous, bnt that it was composed of n bundle of varied-coloured rays, some of which were more refrangible than others. These .oloured rays were not capable of being subdivided into others; hence they were considered primary, and the property of colour was supposed to be occasioned by different substances reflecting oertain particular raye more copiously than others. This theory was so simply deduced from the observed facts, that it immediately obtained universal.belief, and nil former theories died out »ml were remembered only as matters of history. An object that appears white, reflects all the rays indiscriminately, or does not sufficiently separate them to make tho distinction obvious, while a body that appears black, absorbs, instead of reflects, the rays that fall upon it. Simple as this theory of Sir Ienao Newton's is, it must be evident that it advances but a very little way towards settling the troublesome question of difference of colour; for it still remains to be shown why it is that certain bodies can nfloct certain rays more abundantly than others. Sir Isaac attributes this effect to the density of the bodies. He had observed while pressing together the surfilées of two' prisms which were slightly curved, that at the point of juncture the prisms were perfectly transparent, like one piece of glass; but that round that point appeared concentric rings of different colours, sensibly separated from each other. To make the experiment more completely and perfectly, he took the object glasses,one planoconvex, belonging to a 1 -tít. refracting telescope, and the other a large double convex, that belonged to a telescope of 50ft. focal length. On bringing the two object glasses into contact, the same peculiarity manifested itself; at the point of contact the two lenses appeared colourless, and this spot was surrounded by a circle of blue, white yellow, and red; the blue being small, and apparently possessing no trace of violet; the yellow and red were far more prominent. This was succeeded by another circuit, consisting of violet, bine, green, yellow and red, oil in about equal proportions, excopting the green, which was less predominant than the other colours. The third circle was composed of purple, blue, green, yellow and red. In this circle the green was more noticeable, and vied in brilliancy with any of the other colours, except the yellow. The next circle was composed of green and red ; the green bnng very vivid. After this the colours grew more and more faint, and incapable of being detected, till, after a few more bands of colour, they finally terminated in complete whiteness. Since the distance that the glass plates were separated produced corresponding variations of colour, Sir Isaac Newton concluded that colours proceeded from the thickness of the plate of air intercepted between the glasses; that is, that the different colours were transmitted or reflected according as the segment between the lenses was thicker or thinner; and the general law deduced by Sir Isaac Newton was, that the colour of nil natural bodies depended on the density of the body, or the sizo of the component particles.
The experiment of the decomposition of light into its various oomponent rays, is so simple and beautiful, and, above all, so excellent a test for colour blindness on the one hand, and a delicate perception of colour on the other, that we trust many of our readers may bo induced to try it. Let a prism be procured whose sides contain an angle of about 55° (and the more perfect is the prism, the more successful will be the experiment), and held in such a manner that a ray of light may fall upon it from a smull perforation in the shutter of a darkened room. The ray of light will be refracted from its original direction, and be bent upward ; at some distance from the prism must be placed a sheet of paper, to receive the ray of light in its new course. On the screen will be perceived an oblong spectrum containing all the primary colours, at the bottom tho least refracted colour, red, of a most brilliant tone, inore vivid than can be produced by any other means, or than any substance in nature presents. This dies away into an orange, which by insensible degrees gives way toa pale straw colour,
most intense purity, followed by a blue, which, though at first its purity is affected by the green, subsequently becomes of the purest indigo tinge, though the illumination is more feeble than in the yellow and earlier portions of the spectrum, and the luminosity is finally extinct in the violet rays. In experimenting on the ray of light it should be as nearly as possible a mathematical ray. If the perforation be of about Jin., and the distanco from the screen to the prism, say, 18ft., the spectrum «ill be lOin. long and 2in. wide, and show all the phenomena distinctly, and if the sun's rays can be collected by a lens of short fscus the'purity of tho colours will bo much enhanced. Should the spectrum present the appearance we hare described, the experimenter may congratulate himself on being free from any strongly marked form of chromato-pseud/>psis, which is the expression that colour blindness is usually known by in this country, and which means a false vision. On the Continent this peculiarity has received the appellation of Daltonism,* from the celebrated John Dalton, the founder of the Atomio theory, who suffered in a most marked degree from colour blindness, and who has described his own peculiarity with great care, in the "Proceedings of the Manchester Philosophical Society,"and has proposed a theory to acoount for the phenomenon, of which we shall say more hereafter.
To return to our experiments on light and colour, and to completely establish the analysis of light, is will be necessary to form the solar ray again in its integrity, from the many-coloured bands, in which it has been divided by the prism. It will be seen that the distance from the prism to the screen, has nothing to do with the formation of the spectrum. However near the paper is brought to the prism, the spectrum is still visible, though reduced in sixe, whence it necessarily follows that the ray has nndergone division, immediately on leaving the prism. Let another prism of a similar angle be placed in a reversed position (with reference to the first prism) very near the first prism, and the ray of light will be perceived emitted in a direct line from the second prism, unaltered and undeviated, as if no prism had intercepted the ray. To effect the confusion of the different coloured bands, a similarly constructed prism is not indispensable, for a double convex lens employed in a similar manner equally well effects the purpose. White light can only be produced by the assemblage of the entire pencil of rays, for if any portion be intercepted before it falls upon the lens, white light ig not the resalt. If the violet end of the spectrum be intercepted, the light will have a tinge of yellow, and if the blue and green portion of the spectrum be obstructed, the resulting combination of the other lines will be more ana more red, till when only the least refracted portion of the spectrum is allowed to fall upon the screen, a brilliant red is the result. If the rays at the other end of the spectrum—na-«cly_, the red extremity—be cut off, the resulting light will pass through shades of green, blue green, blue, and at last, violet. By intercepting intermediate portions of the spectrum,the resulting light will exhibit every variety of shade and colour that is to be met with in nature. Now, if we consider that all these shades are produced on paper, which wo usually term white, that is when exhibited to the full light of the sun, and all the solar raye are equally refracted, snd that this same paper when placed in the red, green, or blue portion of the spectrum, appears indifferently red, green, or blue, and that this phenomenon takes place whatever colour the body that receives tho spectrum may appear in white light, we are forced to conclude with Newton, that "the colours of natural bodies are not qualities inherent in the bodies themselves, by which they immediately affect our sense, but. are consequences of that peouliar disposition of the particles of each body, by which it is enabled more copiously to reflect the rays of one parti
cular colour, and to transmit or stifle, or as it is called in optics, absorb the others."
Mayer, in an essay "De Afiinitale Colorum," objects to seven colours being received оз primary, and regards all colours as being produced from three primary ones, red, yellow, and blue, regarding white as a neutral mixture of rays of all colours, and black as a mere negatio white. Without departing from Mayer's di any other three prismatic rays may be assumi as the fundamental colours, for Or. Young h assumed red, green, and violet, nnd states as an"1 experimental fact in support of this doctrine, that the perfect sensations of yellow and blue maybe produced, the former by a mixture of red and green, and the latter by green and violet.* Mr. Hay, in his work on the "Laws of Harmonious Colouring," reports on some experiments he had attempted with three primary colours, and he says "that he could not by analysis prove that there were only three colours, but that he succeeded in proving it to his own satisfaction, synthetically in the following manner :—After having tried every colour in succession, and finding that no one could be separated into two, Г next made a hole in the first screen in the centra of the blue of the spectrum, and another in that of the red. I had by this means a spot of each of these colours on the second screen; I then by means of another prism directed the blue spot to the same part of the screen on which the red appeared, where they united and produced violet, as pure and intense as that of the spectrum. I did the same with the blue and yellow, and produced the prismatio green, as also with the red and yellow, and orange was the result. I tried in the same manner to mix a simple with what I called a compound colour, bnt they did not unite, for no sooner was the red spot thrown upon the green than it disappeared. I tried the same experiment with two spectra, the one behind and of course a little above the other, and passed a spot of each colour successively over the spectrum, which was furthest from Ihe window, and a similar result occurred. It therefore appeared to me that these three colours had an affinity to one another that did not exist in the others, and that they could not be the same in other respects, except, colour and refraugibility, as had hitherto been taught, "t
С Го be continued.')
* In fact, scientific men have been sorely puzzled to sutrsr^Rt a convenient appellation that shall accurately express the peculiarity generally known by the term "colour blindness." Mr. Wheweil suggested " Idipots" to designate the sufferers, which, however accurate In its derivation, is too much like " Idiots" to receive any general favour, nnd Sir John Hersehel pro[)os,'s "Dichromic Vision*' to mark tho cauce of biitferinc;. This term (a* its derivation implies) supposes that only two, and combinations of two colours enn be seen by some eye?, while three, and combinations of three are visible to a normal eye. Mr. Pole, who describes with great cure the affection of his eyes, in the volume of the "Philosophical Transactions for 18.'>9," adopts this expresión, and thinks It fully which ш its turn is succeeded by a green of tho explains his Inability to detect certain colours.
STRENGTH OF MATERIALS.^
THE table given last week shows as that iron wire seems to possess the property of tenacity in the greatest, and leaden wire in tho least degree. The tenacity of cast iron is taken advantageof in the most scientific manner in the construction of the Britannia Tubular Bridge. It will be of some interest to tihose readers who do not intend to stndy the subject in its details, to hare some particulars respecting this bridge, and :or these the following is inserted :—The design of the bridge was made by the well-known engineer R. Stephenson, nnd forms one of the most wonder, ful strnctnres in the world. It spans tho Menai Straits on the line of the Chester and Holyhead Railway, within sight of Telford's chain suspension bridge, and was begun April 13, lSti>, completed, July 25, 1850, and opened for traffic, October 21, 1850; total cost, £601,865. It is made of cast iron, of a tnbular form, in the tube of which the trains pass. Four of these tubes span the strait, two of which are 250ft. and the other two 470ft. long. The weight oí malleable iron in the tnbes is 10.000 tons, of cost iron 1400 tons. In the middle of the strait is the Britannia. Rnck, from which it hns taken ih name. The tubes are supported by piles of masonry; that on tho Anúlese* side is 143ft (¡in. high, and from the front to the end of the wing walls is 173ft. These wing walls terminate in pedestals, on which repose colossal lions of Euvptian character, and for each of these 2000 cubic feet of stone were required, each weighing SO tons, and bcin^ 250ft. Cin. long, 12ft Bin. hi^h,
* Young's " Lectures on Natural Phllosopuy."
t Ray " Ou tho Laws of Harmonious Colour loa."
% The right of reproduction is reserved by the Author.