April. THE WEST SHOKE. 121 IRON AS A TANNING AGENT. According to the Baltimore Newt. Prof. Dr. Kapp, of Brunswick, has succeeded in in venting a process for the tanning of hides which has produced a complete revolution in tanning and will, perhaps, be of considerable importance in a politico-economical point of view. The new process does away entirely with the appli cation of tan aud consists simply ui tanning by minerals which substitute a substance far less costly than tan, growing daily more rare, and saves considerable time and 'labor. More over, the process has been practically carried on for some time and sufficient, too, to establish its practical value, which, according to the present condition of things, is beyond all doubt Dr. Kapp's invention consists of three parts first, the process of producing thu m.itin on. plied by this new moot of tanning ; second, the process itself, and third, an apparatus for that purpose. To cure the leather. Dr. Kapp employs basic Biilphate oxide of iron, prepare,! in a pe culiar manner, totally different both in appear ance and its other qualities from the salt of iron known by a similar name in commerce. To pro duce that salt he adds the necessary quantity of nitric acid to a boding solution ot the vitriol ot iron. The development of gas having stopped and the oxide of iron being formed, more vitriol liquid, which, when evaporated, yields dry salt of the oxide of iron, a clear, deep, orange -colored varnish. To cure the hides they are hung in the duly concentrated solution of the Halt of iron, now cold, and they are now sufficiently cured, accord ing to the thickness of the hide," in from two to four tlays, without bring obliged to move, trans fer or subject to any other of the mean pro cesses. With the preparation now ensuing it is not necessary to grease the hides nor hang them in a dry room, or tramp them in a vat or scrape otF the grease by baud or work in the grain by band. Of all the operations formerly in use none are retained in this process but to shave aud perch them. The manual labor is replaced by making a solution of the greasing material in which the hides are steeped, while they arc being dried and tramped at the same time. The fats used to grease the leather are dis solved in the usual manner, and the hides are steeped into it. Besides the ordinary gross. , you may apply stearine and paraffine, never before applied for that purpose. The dissolved grease combines with the eolation of iron on the libers of the hide to a soap of iron to he rubbed imo the leather by a peculiarly OOUltTDOted dram. This drum consists of one of those tramping vats, revolving round hollow plugs, which by means of these same plugs is fastened to a ventilator. Turning that drum the ventilator is set in motion at the same time, which during the tramping in made to ventilate the hides, being tramped and dried at the same time. Evidently the process is very simple, requires but little time, and much cheaper than the model now in vogue. As said before, Kapp's process has fully stood the tost, aud will, ere long, entirely displace the old mode of tanning. Dr. Pol, Directnrof the Experimental Institute forlioalher Industry, in the "industrial Papers," speaks very favorably of Kapp's process of curing leather by iron, for the first time represented at the Berlin Leather Kxositi.m. The tanning with iron works suUtantially like that with alum, equal to tan materials, penetrate the hide, holding the libers apart so they do not re-adhere. Alum, however, is dissolved in water ami is washed out by it. Tanned leather is softened by rain, just like a hide, and stiffens when dry. Iron is washed out iu the same way. Prof. Kapp has removed that difficulty, applying a soap of iron to the leather, by means of which the salts of iron are made insoluble and stay in the leather. Dr. Fol bad lioots made of that kind of leather, now worn by him, which are still pliable in spite of long usage. At the ex position named some shoes were made of iron cured leather by the machines there exhibited. MAKING SOAP IN CLOSED B0ILBB8. A writer in tho Polttlrrhnic Ktririr calls at tention to an improvement in soap making de vised by Mr. E. H. Gibhs, which consists es sentially in introducing the ingredients into t strong closed vessel or boiler, and subjecting them therein to the effects of a high temeraturc and pressure, the intermixture of the ingredi ents being secured by mechanical agitation, in this manner, and with a very simple apratuB, the process of saponification is effected with great rapidity and economy, and it is claimed, with far more thoroughness, aud, as the glycer ine remains incorporated with the product, without the waste, that attends ordinary oper ation with the open kettle. The apparatus employed in this process con sists of a cylindrical steam boiler, through the center of which passes a shaft provided with wings or other suitable devices. This shaft set in motion either by hand or by ower, ac cording to the size of the boiler, serves to keep the charge in constant agitation during the op eration of saponification, and thuB to insure Un complete intermixture and contact of the ingre dienta. The boiler is charged through a hopper with the ingredients, grease, tallow, or oil, alkali, resin, etc., in the usual proportions, and the hniler being tired, the charge is subjects!, under constant agitation, to a pressure of from 120 to l"0 pounds per square inch, which is found to cflect the complete decomposition of the fatty nutter and its saponification in the space of six hours. With a boiler 30 inches in diameter aud 1 1 feet long, it is affirmed that 2,000 pounds of soap can he made and put in the frames in three hours, so that where four runs per day are made from one of these boilers, which we are informed can be done in case of necessity, (three runs daily being the average), the apparatus will make as mnch soap as 24 boilers of the same size would by the ordinary process with the open kettle. It is officially stated that the New York Cen tral and Hudson River Railroad Company s Jan nary earnings were $800,000 more than iu any previous month in the history of the company, and that the total earnings for the past four months aggregated 110,000,000. A CHANCE FOR OUR INDUSTRIES IN AUSTRALIA. The Australian International Exhibition of 1879, seems likely to be of considerable impor tarn. This will be especially true to those engaged in the industries of this coast, for Aus tralia is a thriving trade-neighbor of ours. We should by all means show her what fine manu factures aud productions we can furnish to hor. Australian papers state that arrangements are in progress for the International Exhibition proposed to Iki held in Melbourne in 1S7H, and the scheme has the approval of the legislative Assembly. The Governor, shaking recently at Maw ell, said that the pro(Mnl could not fairly be described iu anv quarter as premature, if regard were had for the wonderful progress which the Australiau colonies have already achieved. In IS79 the aggregate public revenue of the several Australiau colonies will exceed sixteen millions sterling, while their trade, in cluding exports and imports, will amount to nearly ninety millions in value. In other words, Australasia, as a whole, could alreadv take her place amonir the 111 or 12 invat nntsMM of the world m point of value of their trade and gen- ww uupunsuee, ior mere are only seven or eight nations with a larger public revenue tbau sixteen millions. The three powerful colonies of ictoria. New South Wales and New Zealand have each a revenue and trade which would place them on a higher scale than ancient Euro pean kingdoms, like .Sweden, Denmark, and Saxony. The single colony of Victoria, with its yearly revenue of four and one-half millions, is already equal iu wealth and imiorUnee to the kingdom of Portugal, while Melbourne is considerably aWvu Ulbou in wealth and trade. The success of the exhibition, he pointed out, Would depend in a great measure upon the cor dial co operation of tho mother country ami tin sister colonies of Australasia. His Excellency further stated that he was in oorTetpondenofl with the Secretary of State for the o lonies, who was anxious to give every itossihie assistance, and that the presence of the Prince of Wales was all that was needed to render the exhibition a triumphant success. He expressed himself confident that his Royal Highness, if invited by Mh Houses of Parliament, might be induced to come out to open the exhibition, and he wa certain he would be received with enthusiasm. DELICATE TEST EOlt GOLD. Faraday's researches ujkui the nature of thin films of gold and other metals, and upon the iu of finely divided particle of gold diffused through various liquids, are reviewed by the Jnrrtrr: Availing himself of the well-known reducing power of phosphorus, he floated small (articles of it Upon the surface of weak solu tions of chloride of mid, In the course of 24 hours he found that the surfaces of the Liquid) wen- covered with films of metallic gold, w hich were thicker near the nieces of uhosuhoras. jHissessing tho full golden reflective power of the mital, but becoming ho thin bv gradations as to bo scarcely iereeptible. T hey acted as thin plates upon light, producing the concentric rings of colore round tnu phosphorus at their tirst formation, though their thickness then could scarcely lw the 1-l'KHh, perhaps not me i-.HNjin oi a wave undulation ot light. Hy treating very dilute solutions of cold with phosphorus, he obtained the metal diffused through tnu liquid in extremely hue particles producing a Iteautiful rubv color. These nnrti cles, when in their finest state, often reins in unchanged tor mouths, and have all the apjtenr ance of solutions, but they never are such, con taining in fact no dissolved but only diluted gold. 'Phe particles are rendered evident bv gathering the rays of the sun, or a limp, into a cone by a lens and sending the jiart of the cone near the focus into the fluid; the cone becomes visible, aud thotiah the illuminated narticl. canuat Ihj distinguished, because of their minuteness, yet the light they reflect is golden in character and seen to lw abundant in nronor- tion to tho quantity of gold present. Portions of gold, so diluted as to show no trace of gold by color or apiwarance, can have the presence of the diffused Bolid particles rendered evident ty tne sun in this way. THE EVAPORATIVE POWER OF LOCO MOTIVE BOILERS, This important mechanical Subject was dis cussed recently by au English society of mechan ical engineers. The etlort was to set at rest certain widely diverging opinions which existed among practical men with reference to the evaporating efficiency of the various element of a locomotive boiler, such as tho area of the rtre-grate compared with the totri heating sur face, the ratio between the tub surface and the tire-box surface and the rate of combustion per square foot of the tirv-grate. The results of the discussion seem to be as follows: That no fixed rule could Ih; established as the beat for the relative profMrtions of the tire-grate, firo-boi and tube surfaces: that lemdlt .ti tnl. ).,! nothing to do with economic effect: that the iinmeter of the tube was abo mntt.r of uii. fereuce; that economy of fuel did not depend niton the rate of tiriuir: that when the oosntitv of fuel burnt was moderate, say 60 pounds or fill pounds per square foot of grate pet hour, the combustion was nearly perfect, while with hard oiiog mere was coiisu.raPlo loss from onrltoinc xiilc passing away uucouauiued, and thai a lam increase of hoatim: surface in nmtni tion to coal burnt only slightly increased the eco nomic effect, w hich, within 'the limits of pr&ti tioe in locomotive engines, was nearly in pro portion to the fourth root of the heating surface. In au Addendum the action of the blast pipe was discussed. It was contended that. thotufa I povrtrful agent ill affecting rapid combustion, it was, r ,'c, a very extravagant one; yet in general, in the case of locomotive engines, this extravagance was not oliargoaPle to it. since there was a larnc unatititv of steam which was available and would otherwise bo wasted. A formula was riven for csdonlatinii the power of J oi iiiiii, as an agent lor creating a draft, based upon oxiieri incuts made in ISM and 1858, When applied to the blast-pipe of the loeomotive, this showed that, on an average. me power requires 10 lorco uie air ami gases through the lire-grate and tulen was only eltti .-i) oi me potential Hwer of tlie steam escap ing throtutn the blast nine. In conclusion, it was pointed out that a largo increase of effect would be obtained by subdividing the exhaust steam iuto a number of small p ts instead of relying upon one large one, and that, under SrtaiU ci re ii ins lancet, this increase o jMiwer duo no oi groat tunny. EkHuHS IN UfUNl Sl ltVKVOKs' CoMI'ASNhX A coiresfKUident of The Kwiinrtriii.t ami Min ir Journal mentions some minor sources of error in taking readme from the compass wlnl Buneyiug. After noticing certain inexplicable vagaries of a compass needle, and testing the metal of the instrument, and afterward exam ining the nlwerver's pickets to determine whether anything of iron or steel was on Ins Hreon, the csuso of variation was discovered in me iranio oi me magnifying glass. 1 04 frame was of vulcanite, or hard rubber, pol ished to a high gloss; this frame was liable f. liecome electrihed by the slightest frictioo, such as is caused by carrying in the tocket. Fur ther investigation showed that from a variety of similar causes, all ordinary frames of magnifiers are apt Co give like trouble, and new fines had to he specially made which were freo from the detect, l ho impure metal of cases, nvcU and other lwrta may give rise to this attraction; an iron nng is sometimes inserted to fix the glass in the frame. Sometimes the oleerver may un consciously carry the iron in his hat, in the wire that stiHcnsthe hnm. Aluminium, etiitecinlly wnen nammcred, naa the blaming proerty Finally, there is a story of a land surveyor win had the apissarance of his comiiaaa improved by nickel plating, which was applied to almost the entire instrument nail, socket ami sights the effect, of the needle being the same aa if tb brass had been coated with iron. Hini'Eln Small Tools. It is said that the engravers and watchmakers of Germany harden their tools in sealing wax. The tool is heated to a whiUnesa anil plunged into the wai withdrawnMter an instant and plunged in again, the process being repeated until the steel is too cold to enter the wax. The steel is said to become, after this process, almost aa hard as the diamond, and when touched with a little) oil or turpentine, the tools are eicellent for en graving, and also for piercing the hardest Coal-Tah Colohk. -Iu a recent lecture, ii Lmdon, Prof. Armstrong reverted to the nre posed extensive production of coloring matters from coal tar, from which great thing! were prophesied some yc:irs ago. It was found that though analine wan yvlded n.oi . ,.d tur m Imt small quantities, Mhfnl wnsyiehled plentifully, and that, by the addition of nitric acid to it, uitro-U'inol teas formed, and this, when sub mitted to the action of reducing agents, win converted into aniline. I pus a OUOap ami plentiful source of aniline from coal tur was MUM 20 years HO discovered. from this aniline we have dyes of violets, reds, yellow, green, hlue ami many newly-discovered shailcH. Binoe England has so large a supply of coal, it might have Ik'Cii exK'ctwl that she would soon have be independent of the supply of animal and vegetable dyes from abroad ami have been the greatest color-producing country in the world. This bus, however, not been roalircd and England is gradually falling further and further iK'hind Germany and France. The reason is given by prof. Armstrong as follows: " tlnr iiiauu fact u rem do not nttenqd to amnio! the co-oHration of skilled chemists. If they were to seek them in England, they would pot obtain them, as there are so few that have had the requisite training to conduct tho work. We have in England no school where instruc tion is given in tho particular kind of chemical work that is required." This result Prof. Armstrong attributed partly to the indifference of English Universities to the practical wants of the country. AN ENGLISH IMPROVEMENT IN BLAST ING CARTRIDGES. W e read that imnrovements .teviaed bv Englishmen have for their object thoaffordimiof greater security, ease and facility than hereto fore in manipulating, transporting, and storing iniiinijiUB, ami consist in malting cartridges BUM or to ho filled with gunpow der or other MOivalaut explosive matter, in the ontinrv manufactured state or iu any state of manufac ture, hollow, with au Inner tube or tubal pass ing through them, ami by means of such tubular or hollow space or ptveea, passing ono mm iwsss Mnnn sucn cartridges; and also, hen it is nnuired to increase tin. eh.eu., afforded hy ono such loaded cartridge, stringing nu oi murv oi sucn carmiigea together on ttio said fuse or fuses. Also iu turning up, looping, or otherwise treating the fuse or fuses so intro duced for the purtHisc ol seciiriuc mul m im- tb cartridge or cartridges strung thereon. The cartridge is to bo made id any convenient mate- rial, tabular Ot any desired shape iu section, and of nu inner and outer tube nr chamber arranged concent riojilly one within the other, or othorwnoj, ami (orating U'lweeu them a hollow receptacle for the reception of the gunpowder or any ether explosive equivalent; and the ends of such chamber or hollow receptacle are to lie formed of or secured by annular disc or other shaped pieces, so secured to tho walls of tho hollow receptacles that when completed and chargcil tho explosive material shall not fall out; or other convenient modes of securing the ends may be employed, hut in nil eases so arranged that the fuse or fuses pass easily, aud so a hoi low cartridge Ihi formed ready for stringing oua fuse or f lines. A Bnctat Cut. Mr. Johnson, a traveling musician, being iu Garlaml, Colorado, and anx ious to depart, manufactured a velocipede, with which he propoeed to travel into Texas. Hav ing become iiosscssod of two tw o-wheeled vohw). ijiodes, such as were in common use a few years ago. he proceeded to foitttl them together to run on a railroad. Wooden axles were con Mulcted so that the machine could Ih adapted to any gauge of truck; a broader trend was placed on the Wheels, to which were added flanges Blade of whisky hnrrel hoops; lovers were fitted to give means for using the hands as well as the feet to gain motive power. The whole arrangemant was given a coat id red paint, and it was placed on the track at Gurlaml ivaily for M h e. The machine weighs about 40 pounds nnd is easily humllcil. The operator sits oil a seat, resting across whnt were the two sents of the old velooi pedes. Johnnon mounted his novel traveling apparatus at Garland, and pro- Deeded without accident, traveling at the rafo of IB miles per hoar. Altering the gauge of his car t suit that of (he Atchison, Top. ka A Santa I'e railroad, he started for the East. Johnson is mi old railrond man. and nlwnvs provides himself with a time-card, n thnt he can keep nit of the way of the regular train. Ilispia-atu-is so light that it can Ik mm cd from thu mill iu n moment Pmr.K rOR KiMKAiu hk-h OoiCUUniia Oxvnits. - -The influence of the animal organism of breathing pure oxygen gas of density corre sjwniling to ordinary atmospheric pressure, has not hitherto been adequately determined. Thu Royal Society of Gottmgen, says Xnturr, there fore offer a priwi for new researches on the sub ject, made Uith on homoitliermsl, ami, as far as possihie, on poikilothermal animals, hi these researches, while certain uxternally visible phenomena in the animal will have to m con sidered, siiecial attention is desired to 1w iriven to the nature of the blood and the exchange of material (excretion of carbonic acid and nature of urine). I he oxygen used should to carefully freed from all foreign matters apt to occur in manufacture, whilu a limited (ami NirhsNi hardly avoidable) admixture of atmospheric nitrogen would not compromise tho results. In the Nlathematical class, the Gottingen society desires (and offers a prire for) new researches in the nature of the uuKilariHd light-ray, " fitted to bring the conceptions of natural light of any origin near (in definiteness) to those which theory connects with thu various kinds of polar ised light." Test mK Alcohol. -A very sensitive res :-. r.t for ileohol- wid onn that ii verv mimiiln in its mode of application, savs the English 4 thanif, has been found by SI. .laoipuemart, It is a solution oi nitrate oi mercury, oPUiurtf Uy treating the metal wfth a little nitric acid of average concentration. The action is rigorous and rapid, the mercury is hrought in part l the minimum of oxidation, and it a little am monia be added to the mixture after reaction, a dark precipitate is obtained, which is darker the more of alcohol there is in the prodnct sus pect Methylic alcohols and similar liquids do not give a dark precipitate with ammonia. AftinoinBsKoiirnMu. For measuring highta not eiceeding one-quarter mile above the sea by means of ths ansroid, Admiral Fitarey proposed the fuUowing method: Divide tbs difference between tbs reeding at the upper and lowsr stations by 0.011 ; tbs (jootient is tbs approxi mate bight in feet. ItriitonitKJisioN at SliKKKiKi.p. Tho Iron Bauer's Rttteutkm A few dnva amount' the old. st scissors insinifuettirers' iu Shellield, w hose holiness lies chii lly w ith UuMOU houses, ceiled upon a welldxnown Arm in Bond ttreet, ami urn principal mtonrn ! lnm thnt tin y Hero going t" exhibit nt the Pnris Kxhibition, and the WMted him to make thorn n set id elnlio rately wotked scissors, something that would show tho progress thnt had been RUdtof lato years iu this siteeial Jirnnch of industry. "I colli. lot do it,' wan the answ er. ' Ohl lion. si nce," saidthegenfh iuniiof llond street; "you reinoiiiiier tliose splendid goods you mn.lo us re than 90 years ngo, and which we hud at the Kxhibition of iH.'d. Ileru thuy are ;" ami he produced from a drawer some of the most cwmiisitclv beautiful scissors that had ever left a Sheflield workshop. The manufacturer looked u I ton them with almost paternal affection, and then said, "I could imt umku you such goods now if my life depended upon their production." The result of the inlerview was thnt these old scissors were brought back to Shellield to be polilhed up, mid they will do duty again in the Paris Kxhihitiou; and we venture to predict that they will command no small amount of admiration. Tlir OUR ok (UnnoAM, In reply to an assertion by Mr. Huntington that the Pennsyl vania railroad P '.".m pormile, Mr. Thos. A. ott stated iK'fore a Committee of Congress thnt this was simply untrue, ami added: "If ymi will bike up the roort of that road for the last I'tsen year, yon w ill sue that the cost was f.'IH, 000,00000 MO miles of road, orl900fJ0tmUtVA very moderate cost for ou it of the I test construct ed lad MOjnped niadslhsvingad'nible track and stel rails) in the Unitinl States, if not in tho World." Thechespnens tf railntail construction iu these hart! times i very clearly nhown hy the fsct that the Chicago ft Alton Cointany, which is not one that will put tip with snythiug less than a first-. Uss structure, has lets contract for the extension id its Missouri linn to Kansas City at the rate of $l,',0KI jmt mile, excepting tho bridge ovrr the Missouri, the bridges to lie iron ami the rails stetd. As the company can get money at alxuit & , it will only nted to make slsiut l,00( a year net earnings to jwy interest on this cost. Tut Psanran ann m Bncften, A dis patch from Washington ssys that President Ifaree, in company with Allwrt hierstalt, the artist, who is now visiting the Kiocutive Man sion, spent a considerable p.. Mum of an after niHin at the Washington headquarters of the Hayden survey of the Territories, and evinced great interest in the exhibit made by the Pro fessor aud his assistants of tbs methods and results of ths scientific- work of ths various espaditions. MaKurarrt ataa' IUiLwava.--Krupp'i vast cannon and rail manufacturing establishment in Germans, aays the Itaitimy Aai, illuatratee the adaptability of the staem mad to private indue trial uses, as it contains over .17 miles of railway, with 34 locomotives and 700 cars. Of station ary engines and boilers there are no less than SIM, representing 25,000 noma power.