178 Franklin I~slitule.

nearly insohlble, while the sulphate of lime is somewhat soluble, and tim chloride of calcium very soluble, and thereibre likely to produce corrosive action eventually. Still the operatiott of whitewa:~hing is the simplest mode of obviating corrosion, and may be repeated at in- tervals.

The content of chlorine to such an extent as is developed by the above chemical examinafion, is imeresting in a geological point of view, since it has not hitherto been lbm~d in chemical examitmtions of mJthraeite. Proll II. D. l{ogcrs, it1 1836, pointed out the titet, that where tmaps of r('£use ntatter were burned near the coal mines, ammo- niaeal salts, arid among tllem lflll.l'ia[o 0[' ammonia arc sublimed, alld may be ibtmd among 1}m ashes. Now we know lhat salit~o waters are oblaim;tl l)'ont the cecal measm'cs in the western district ot" Peru> sylva~aia, alld moreover, it is lhe prevaiiiJ~g opiHion among Geologists, that lhe coal st..ri(~s are marine deI)osites; we can theretbre explain the origirJ el'the mm'iate of ammonia in fhe ashy deposite arising from the combustion of antt~raeite, by atlributing the chlorine to the presence of a trace of cIxlorid,.; of sodium (COl-l][rlOll salt) in the cotfl or its ae- eompanying slate, or possibly i~ both. It is ulmeeessary to allude to the lbrtnation of ammo**ia, since it is a mfiversal product l o a greater or le:ss extent of' the dry dislillation or combustiot~ of'every kind of coat.

This a.lllmOLliaea] dCl)osite is interc~sti~,g in :m economical point of view, sblce it aeeml:mlatcs in considerable quantity in a single season, and may be collected with fitcilitv. In one itJstanee at least, ten pounds were removed from about c'ight to ten [bet o( pipe, whielt was the pro&me of three or :/bur years, alld hence, we may estimate the large amom~t that might be obtained from really htmdred t)il)eS in Phil- adelphia e, verv season. It may be employed either ibr the manufiae- ture of sal ammoniac bv a very simple process of sublimation with a small quantity of ~t salt of lime, or it may be directly applied in pow- der or in solution to garden-soils. The influence o fammoniaea l sails in promoting luxuriant vegetation has long been known, but the ad- mirable work of Prof. lAebig on Agricultural Chemistry, has more eomp]etely developed their influence and importance. The material before us will unqueslionably prove of great value to the gardener and florist: it' properly applied to the soil; bnt it must not be ibrgotten that t is very rich ill ammonia, and should therefore be employed spa- tingly.

By order of the Committee, February lOlh, 184 °. WILLI_¢3~ HAMILT0> ~, Actuary.

Baldwin ~" I?aiYs Locomotive .Engine. 'he Cmnmittee on ScierJce and the Arts, constituted by the Franklin Institute of the State of Pennsylvania, for the promotion of the Mechanic Arts, to whom was referred for exami- nation a six wheeled, gearcd, Locomotive Engine, intended for the t[ansportation of heavy freight trains, manufactured by Messrs. Baldwin & Vail, of Philadelphia, Pennsylvania, REPORT : - T h a t the s u b - c o m m i t t e e a p p o i n t e d to e x a m i n e the a b o v e m e n t i o n -

d e n g i n e : m e t u p o n tim C o l u m b i a ra i lroad on the 25th of J a n u a r y ,

B a l d w i ~ & TZail's Locomotive Engine. 179

1842~ and went witil the engine out to tile Schuylldll bridge, and re, mrimd with it to Broad street, drawing a train of burthen cars, the gross load being about 200 tons, which was much below the limit of the engine's power, but included all the cars that were theu ready to be brought in.

:File peculiarity of this engine consists iu its obtaining the adhesion of the tom" wlmels of the truck~ in addition to that of the main driving wheels, without preventing the truck from vibrating so as to accom- modate itself to the curves at~d uudulatiot~s of the road. ]~,'xpcrience upon the Amcrieal l roads, as iitr as known to tiffs committee, proves tltat et~giues having six wheels and provided with leadinu lrlteks~ ......... muclt n]ore steadily than those with only four, and, as ~pa,'tia]'t;Osso'[" po wer and other irJjurious consequences result fi'om the slipping of lhe driving wheels of locomotives, (which often occurs to a considerable extent, even when it does not prevent the engine from drawing its load, and is not noticed by the engine-man) it is very desirable to ob- tain the adhesion of all the wheels, without losing the adwmtages of a vibrating truck.

The dillieulty in doitlg lifts arises from tile f'aet~ tiult when lilt', en- gine stamls 011 a curv% tile, axles of the truck wheels are nol parallel to that of the main driving wheels. Messrs. Baldwin & Vail obviate the dillieulty in the tbl[owmg manner. A p.~ir of main driving wheels, ibrty-lbur itmhes ill diameter, are phleed behind the fire-be,, as in iheh' wc[l-I<nown form of engine, but the axle, instead of being crank- ¢,.d, is straight, and the conneetil~g rods fi'om the pistons of the cylin- ders hare outside comtexiems; ~'~ and attached to tile same wrists are o~hcr comleeting rods, extending forward and giving motion to a shaft umier lhe front part of the boiler and between the axles of the truck, whie!t sha(t is secured so as to maintain its parallelism wiih the axle o[' the main driving-wheels~ at right angles to the axis of lhc boiler. 0u tile middle of this shaft a cog whee[ is fixed, having chilled cogs slightly rounded on the fi~ee, wlfich, by means of two intervening wheels, give motion to others on the axles of the truck. 'l'hc, four trttck-whccls are thirty-three inches ill diameter~ and the gearing js proportioned so as to make them travel at the rate of the larger wheels.

The steam cylinders are thirteen inches in diameter and sixteen incllc:S stroke. The gro:ss weight of tlle e~gine in running order is ~o9,980lbs., which is apportioned so that 11,755lbs. are on the two poinls of eolltaet with tile road behind the fire-box, and 18~225 lbs. on the ibur points of contact under the truck. When tried upon the Co- lumbia railroad in the presence of the committee, the engine drew" its train readily around curves of 757 feet radius, the rounded surfaces of tile chilled cog gearing alloxving the axles of the truck to suit them- selves to the curvature, of the tra.ck. '['he engine passed wilh ease around a curve of ninety ~legrees, having a radius of' Sle thet, the train being detached, and afterwards backed itself'around a curve of'seventy- .five feet radius without dittieulty.

The engine has since been in use upon the Reading railroad, and it appears fi'om a certificate o f Mr. N ieolls, the Superintendent, that on

* This improvement is applicable to engines with cranked axles.

180 Mecha¢Hcs ' Regdster.

the 12th of February, it drew ti'om Reading to the Columbia railroad, a distance of fifty-fbur miles, a train of 117 loaded freight-ears; the ears weighing 215, artd the fi'cight 375 tons, making a gross load of 590 tons. The speed when in me(ion being ten miles per hour.

In the opinion of the committee, this engine combitms ill a high de- gree the advantages of a vibrating Ii"uek with the usa of the adhesion of all the wheels; ~hey thiHl¢ it well worthy of the attention of rail- roa(1 companies doing a freighting I)usit)ess, and believe that it will add to the deserv(,dly high rcl)utalioll of the builders.

lly or(ler of tim Com)aittee, WII, I, L t.~I IIA~IL'rOX, Actuary.

~[,'eDr~tar?] 2 ls[, 18.12.

~7~c c h a H i c , ~ ~ Jig e g i ~ I e l ' .

LIST 01;' A M E R I C A N P A T F N T S \VHICIL ISSUED 1N DECE3IBEI ' , , 1840~ AND

.rAxvArY, 1841. IUil/~ ]lem<tr/es a~c[ ]*):ee~nI~lUiealions ~y t/ze Ft{itor.

51. For improvements in Ucth,'esJbr lhe Pneumatic ]~aihvct?/, appli- ectble to other purposes; Samurai Clegg and .laeob Sanmda~ Sid- mou(h street, (~ray s Inn lane, Middlesex county, England, l)eeem- bet 31.

The s~bject of this l)alem is a mode of renderit~g air-tight the valve which closes tip the slot, throvgh which passes the connexion be- tween the carriages of the i)ueumatie railway and the piston working in the cylinder, mid which is applicable to machinery ia general, in which such eomiexiou is recluired. These valves work on a hinge of leather attached to one side of the slot, and the other tklls imo a trough filled with a composition of bees wax and tallow~ or bees '~vax and oil so compounded as to be solid at the usual temperature of the atmosphere, and fluid a few degrees above it. Tile valve is opened by the connexion between the piston and the carriage, or other body outside, and fidls back after it has passed, and is pressed again ill its place by- a roller, or other body~ passing over it; and this is followed by a heated body of metal~ which melts the compound, and herme- tically seals the valve.

C la im. - - "We do not claim the precise size or form of the various parts, or the using of the precise materials herein described; but we ~laim exclusively the method of constructing m~d using valves as :mrein above describe(], tbr rendering available the application of d[- :eel tractive three, either on railways or otherwise."

For a mode of Grctdualinz~ lhe velocity of moving bodies; Edwin W. Jackson, Albany, New Yorl 5 January 5. This patent is obtai~ed for a mode of regulating the velocity of

goring bodies~ which are subjected to the influence of an irregular or