342 EVE’s n/lelallic 6amis for CO?YU?6~6l&iCUling’ MO/ion.

pvement, as my inrention or discovery, is-the form of the sharp- eners for the aforesaId purpose, bemg_thm circular plates, requiring

or room, easy to be re alred, and tnfllng in expense. further claim as my ri ES t Of invention? the fixing, can_

or attachmg the sharpeners to the carvmg fork, or any thereof, either for the double purpose of guard and

or for the single purpose of a sharpener.”

21. For an improvement in the Machine for Pressing, utzd Raising Weights; Mayer Cummings, Mayville, Chautaque county, New York, February ‘19.

This is simply a rack and pinion press; the only difference between it and those ordinarily used, bein

B the formation of teeth oa both

sides of the rack, and the USC o two pinions, and two cranks, or levers, to work it; by which means the patentee believes that much friction is prevented, and consequently more effect produced by the same power.

SPECIFICATIOXS OF AMERICAN PATENTS.

S)eciJication of a patent for improvements in c0mmunicatin.g Power and Motion, by means of Metallic Bands, and their application to various purposes, and particularly to a Botary Pump. Gratued to JOSYPH EVE, Of .&.4gusta, Georgia, i&y 1, 1828.

MY said improvements consist of the following particulars: Rust, I cause bands to be made of thin plates of ‘any metal, alloy, or com- position of metal, that may best suit the particular purpose for which they are intended; which bands I use in almost every place where leather or cloth bands, or cords, or catgut, or chains, have been heretofore used for impelling machinery by means of pullies.

Second.-My second improvement consists in the application of metallic bands, as above specified, to elevators on the plan of Evans, or others, or to chain pumps in place of chains, to turning lathes, many kinds of light machinery used in the manufacturing of cotton, &c. and more particularly to a kind of rotary pump or water eleva- tor hcreaftcr to be described.

My first particular is depcndant on the following quality of metnl in common with many other materials, which, though well known to every person, has never been considered, or improved, or made use of, for any mechanical purpose, to my knowledge, in the manner aud for the uses I am about to mention and explam.

All metals, as well as their compounds and alloys, arc elastic to a certain degree; even lead and copper; which elasticity may be improved b bl\t’ this

tempering or hammering, or by pressure between rollers: c asticity has its limits, if carried beyond which, some i

rllctals will break asunder, as steel, and some will take a a$ so to

EVL’S Melullic Buwds fur Comnu,kcatiq Motion. ~43

e\prcs~ it, as soft iron, copper, &c. But within the Iin& of their elasticity, they are capable of being bent backwards and forwqls fnr ever, to speak in common language, without change or injury. Ynu may pver+cnd a steel bow, and break it; but if not bent beydnd its pro04 It ~11 never break, however constant or long it is- med. III like manner, a sheet of tin (tinned iron may be wrapped rouod a cylinder of a certain diameter, and wi 1 become strai I ht again wlm let go; but if you diminish the diameter of the CJ mder be- g. yonrl a certain degree, it will take a set if bent round it, and require strnighlenipg every tlmc you thus apply it; and if wrapped round such a cylinder a ain and again continually, and straightened as often, there is no oubt but that in time it would break asunder. $

It follows, from the above premises, that if thin plates of metal be applied as leather bands arc, so that the bend of the segment they touch be not too great for their elasticity, they will not break, or undergo any change in their structure, thou@ the pullies be made to revolve cvcr so long or so fast, or whatever force be a plied within the limits of their strcqth, cvcn when straight. I cre then we P have all the dcsidcratn of’i band, and, probnbly, the best means yet known, nf communicating power and motion to a great distance; OIIC of the greatest difXculties in practical mechanics. But metallic bands applied over the smooth surface of pullics, would yield or slip if considerable resistance were opposed to them, and this is a fault tlicy have when simply applied, In common with leather and other bands, but, perhaps, in a greater degree, from their being smodther; but they admit of a rcmcdy that other bands do nof, which is, that of having cogs soldered on their under surface, which I have done very succcsstully, workin, w in.grooves on the surface of the pullies at such distances, that about s1.y shall be equally divided on the phery of the ullcy; or there may be metal points projecting rom

? Fe”-

the surhcc o the pulley, and corresponding holes made in the band; these methods, and there may be nthers, band from slipping, under any resistance, and are anal and other contrivances resorted to, to prevent when used in chain pumps and for other purposes. may be made of tinned iron. (common tin plates,) or tinwd copper, or iron, or copper plates, &c. untinned; but sheets of steel are much better than ,any other material ; having double the strength an$ elasticity of any other metal, they may be made so thin as to be. ap plied to the smallest ullies. Endless saws have been applied this way over puliies ma e BO large as nnt to bend them beyond the Y limits of their elasticity; but here the application 4s not that of a band to communicate power and different degrees of velocity, but as a means to give rotary motion to saws.

My second particular consists in the mode of applying metallic bands to rotary pumps or water elevators. A reference to the an- nexed diagram, will best explainamy mode of doing it.

3/l-$ )~VF.‘S Jf~?fU.?liC i31L1LdtS JbT Coln?~z~lnicating i&lfi~ji

A,reprcseutsapullcy~f 18 iuches diameter, with the axle and handle, or winch. The ccntre of this pul- ley is placed about three feet above the platform of the well, 01’ SurfMX of the ground. It has high edges to d prevent the hands from slippung ox There is a pulley at the bottom of the well, like the above in every re- spect, except that it has no handle. It serves to guide the band, and is placed within a few inches of the bottom of the well. c, c, a band of d sheet tin 3; inches wide; the length of course depends on the depth of the well, and, it necessarily t’ollo~, that if the same number of buckets are used, they will be farther from, or nearer to, each other, according to the depth of the well. d, d, (I, (2, kc. tin buckets msdc square, con- tainiug a quart each. They are of the same width as the band, aud at- tached to it by 2 knees, that pass under the band and up the side of the buckets. There are 24 buckets, placed at equal distances, which number of buckets may bc used for any pump for domestic purposes, be the well of greater or less depth. This will equalize the power to raise water from any depth, by makiug the water delivered in a given time in the inverse ratio of the depth of the well; that is, but $ of the water will be delivered by the same power in the same time from a well of 100 feet deep, that will be raised from a well of 25 feet by the same power, in the same time. E, is the spout, that receives the water; it is placed on the side of the pulley at right angles with its axis. f, &c. the cngs, continued all round the inner surface of the band, at about 9 inches apart, or exactly g of the periphery of the pullics; they are placer1 in the middle, and are half its width. They are made of sheet tin soldered on; as their office is on1 to keep the bands from slipping, they will never wear. They all into grooves made at 9 corresponding distances on the periphery of the pulley.

I made my expcrimcntal pump to the above plan, and of the di- mensions and materials there specified, and it answers very well. The well was 25 feet deep. It delivers, when the pulley is made to revolve 60 times a minute, SO allons. A boy or girl 10 OF 12 years old, can work it with tolerab e ease. I do not confine myself Y to the particular mode of making ‘these machines described above, or to any dimensions. The materials also might be varied; leather bands, 8~. and wooden buckets, &c. might be substituted. Though I am of opinion that tinned copper plates would answer better, as be- iw more durable than any other material. The pulley beam may .

I’LAN~UL’S Terru-.3felaflic Teeth. 34’5

be mmlc of c3st-iron, without nrma or axles. A mere ring with tIsnchrs 111 Leap the band from coming off, or an immovcable crrcfl~ @de, mny bc wbstitutcd in the manner of the modern chainpd$a W~IC~I have 11~ whcrl at the bnttom of the well. These pumps a ’ pcculinrly adapted to deep wc1ls, or shafts of mines several hundr feet deep.

2 JOSEPR EVE.

TILL this importnut improvcmcnt, nnc or two sInnIl pircrs of pla- tinr, wcrc insertrd intli thr tc-rth nt the time of their bhricntlon, which much we3lirnrcl thr tcl*th, an11 very clftcn caused Lhcm tosplit in the bakin

P’ or in the soldrrinp rid more ol’tcn came out or sepa-

rated itself ram the teeth when in use; all tlicsc great disadvantagea are rjbviated by not inserting any plRtina into the tcctl~ at the time uf their fabricationy and mstrad 01 it, to make, with a small wirr, a hnlc throu,;h the teeth, which, afirr the baking, is stopped or lillctl up with silver. gnltl. or Iblntin;r wire. and ~uld sulder melted on both cxtremik r)t it; this n1ld3 1nuc11 to the strength of the teeth, and the1 are lighter b> rll)t usin;: plarina. ‘I’ccth sn mndc, and of a good material, ncv(‘r will brrak, or srpratc themselves from the wire, nor the wire from the plJtc; tid to its pcrkction. for artihcial

which brings the irt of the dcn- teeth.

In order to secure to mgstllf the ndvanbges which are to result to socic!y from thk imprnvrmcnt, nnd tu prevent the common p”c’ tice of infringing pntrnt right+. 1 also spccif that porcelain teeth may be well sccurcrl to a plate. if thr small ho c III made in the teeth, i. without pasGrq entirelv throu$~ them, and dtcr the bakin a wirs- of silver, or gold, is -illtr~,~lured into the hole, and p d eoldcr f mrltcd intn it. \rhi<h III&S a prrfect held, if at the time of the fabrication of the teeth, the said holds 3re made a little larger at the bottcml than at the tq; thi* mode would be still neater, but, perlIsps, not SO secure as’the other.

I must say that these important im rovrmcnts have been &UK- ptcrl to mc bv necr9kitr. ahich is tru y the mnthrr 01 invrntiori; r plstinr brin, *V ai tllili tim,l bo dear. LO scarer, and. in fart. not king able tn nhtairr all!. 1 habe malIe erpcrimrntri, IIIIII haye Ijrmcd trrlh without it, and solderrd them ho \\rll to n ppltl IllatC. thilt 1 Ilnvl* no cl0ubL experience will snnn pr~~\r that this nrw Illflflr hs a ;rrnt WI Ierinrit . uvcr tllr anric.IIl.

\*,I.. ,h .\. l’I.A~lfrl~.

.-So. .3.--l\lrr. II:!‘,. -1 I

~pe~i@ilion Of a pUhl~f’0~ CUl i?llpr’OVel~lC~lt in LOComolil;e Elagiplcs,

or Carriages, Propelled by Steam, on Rail, OT other Roads, denmi_ nateli the ~6 Improved Locomotive Cakage.” @anted to wIL_

L&I HOWARD, ESQ. United States Civil Engineer, Baltimore, Maryland, December 10, 1@X

(WIT11 TWO OOPPER-PLATES.)

TO render the locomotive engine, or carriage, capable of travel_ ling on a curved road, without a much greater degree of friction than is encountered by it when moving on a straight road, two thingsare necessary.

1st. That the axletrees be capable of adapting themselves to the curve of the road, so that a perpendicular phme drawn through the centre of the axle, will be normal to the curve.

2nd. That the wheel moving on the outer rail, or larger circle, shall be capable of moving faster than the opposite one, without de_ ran ement to the machinery.

# hese two ends I accomplish as follows, and claim the same as my invention.

1. The arrangement for joining the axles is thus. The usual beam fastened by jaws to the axles, is divided in the centre, and a tooth and socket permits one end to play in the other. This con-

trivance, as shown in my improved rail-way carriage, obliges the hind wheels to follow in the track of the fore ones. Besides this, there is a beam extending from one axle to the other, and traversing on the centre of each, round a strong bolt. To this beam, the boilers with the cylinders are attached. The boiler, indeed, may be made to answer the purpose of this beam, by placing it upon beds, beneath which the axles move horizontally around centre bolts. At each side of the boiler, and attached to the axles, and moving with them, are perpendicular supports or guides, with openings for the vertical motion of the endsof the shackle bar of the piston rod; each pair of supports, or goides, being connected at the top by an iron bar, in the centrc of which is a bolt connecting it with an iron frame passing lengthwise from each extremity of the boiler to which it is fastened, and which keeps the supports, or guides, in their ver- tical position. This last bolt is directly over the bolt of the wagon bed, as well as over the centre of the cylinders,, so that when the axle moves horizontally around the wagon bed bolt, the supports, or guides, moving with it, make the bar connecting the supports, and which is always parallel with the axle, revolve round the bolt m the frame above the boiler and cylinders, which are stationary; and the shackle bar movin at the same time horizontally, with its uides, around the head o ’ the piston rod, which is constructed to a low of P ? such motion, the horizontal motion of the axle does not interfsrs with the working of the engine. To preserve a uniformity of mo- tion, a balance beam, supported from the boiler bed,, is connected with the shackle bar of each piston rod, so as to allow of its vertical

IIOWAHD~S Improved Locomotive Carriage. 347

motion, and, at the same time, the horizontal motion an .alteration of the direction of the wheels. original, the principle of making the shackle bar head of the piston rod, and the means by which this is accomplished.

2. I make the outer wheel go faster than the inner, when ne%le, aar , in this way. The axle revolves as usual in rail-way wagone, am r the carriage wheels revolve likewise upon the axle; but at the extremity of the axle, there is a ratchet wheel fastened, to the rim of which the connecting rod from the shackle bar is fastened, instead of to the carriage wheel, as is customary. From the rim of the car- riage wheel, there is a catch and spring striking the teeth of the ratchet wheel, and uniting the two as one wheel, except when it becomes necessary that one carriage ~hecl should, in describing a large circle, gn faster than the other, or, in other words,faster than the axle and ratchet wheel. ‘I’hc carriage wheel then moving faster than the ratchet wheel Etstencd to the axle, the spring and catch on the rim slide over the teeth of the ratchet wheel, until a straight motion makes the catch hold tbc teeth again, or a reversed curve causes the opposite wheel to perform the same operation.

Here I3 is the carriage wheel, and A .~. the ratchet wl~cl. The wheels going in the direction U, C, thr catch C makes the twn wheels but as one: but when I3 goes .* faster than A, or than the oppnsite wl~ccl, then C slides from c to a, and b, kc. SK., where it is again held stationary un re- suming .2 slraight course, or a ~~cvcrsect curve. So that the engine, notwithstnntl- in&the altered velocity of the wheels, still performs its motion. with regularity; no change ever taking place in the velocity of the ratchet wheels. The whole of this invention I claim as new.

WILLIAM HOWARD. .

DESCRIPTION OF THE DIIAIVJKGS OF ‘THY. IMPROVED LGc~~~ . -x-

ESGISE OR ChnRIAGE.

III Fig. 1 and 2, Plate VII., and Fig. 1, Plate VIII., the.‘same.$& tcrs refer to the same parts.

A, the boiler resting 1~11 its bed Ii: R, l3, the cylinders. C, C, the cnnnccting rods between the shcklc bag rrnd th rat..

chet wheels. D, D, the supports or guides I’ur the shackle bars. E, F, the iron frame .attached to the boiler, and united to the

guides by the bolts S, S. F, F, the axis of the balance i~cm. G;, ci, the arles. H, the boiler beds. I, furnece door. K, the carriagr! whrr:lr

R.,S j:~tow~*.5 Jc’cd/Or ‘lirrc Gg or Ifudin~ Ilctlcs, ,\ ,

,** I,, llll! ra1clwl wheels. hl, tlw bull unilin, 1~ the luilcr bed and the rxles. (), 0, tllc ollwkle bars. 11, (IN junclion d the balance beam with the @tan r01l. v, .$, bolls uniting the YUpporls or guittcs wi1h the frame I:, k:. \+‘, the 1w1l1 rncl socket of the beam usitiq the azlcy. y, awl a. thr catch and spciq %, tl1c lulr11cc bcura. l’lil1C VII19 Fig. 2. A, tbc! arlc. I), ~IIC fiupport or guides. C, the shuuldcr lbr ~IIC carriage wheel. fi ), ~IIC octilguii Cur tlic ralclicl whacl. Fig. 3. I\, tlic cwriiqc \vlicct. I), the rdchcl wheel. (I, tlrc connecting rod. I), the catch. E, the spring.

.

a, b, c, d, Q, the teeth of ratchrt wheel. Irr thcsc draaiap, Irklion ~~III:L’IJ 3114 1he CICI~II~ 4‘ S~~Q~II I.,.:

c.lbincry have been oiui1lccl. lur tlii: ~~11ftl~sc of IIdiIlg tt18: &.l\\ 11,; cnsicr 10 br unclcr~lon~l.

.\i~ c.~/i/ic*utiou 1.~1 II ptcnt for a mucltit~c calid Urotrn~s Rd fur irk. nitiK, or Ifu)itilitr,g, /lib, AXbs. 4-c. iy whiclr u grCnt pm 1 14” I:. e h&our is rrcrcd. UP if obrifdcs llrr ncccrsity of Idiltg Ikc~rr 04 ‘:I

thC 7wt, In chicd,y llrtii posilion. ~;iffI,/ctl IO \\‘ll.l.l\v Ihif,\~ .N. ‘liotnrr, A’fnsi,t;lo~l, /‘ltilrctlr$fiitr troimty, f’rrl~l.!lfi.(l)li(l. .‘7[ I i! I ;r/c, I VS.

‘1’1il-i liiitci~iiic ib n 13~1 nr cvliedcr, of tliincii5ions siiitcd to IIIC 1 ;\t iti which it ii 10 bc USCYI: ii runbis1s uf two or inure c!lirdrir~d \vIICclSi, eilllcr wlid or olhcrn iw, thcc~l al cc:rl;rin tlislr\nw~ ilIKll t. Jd pOperIp liaw3l1o~~ll~rr,will~ a shilfl, or3sis,txissin;: ll~ruu~li llwit C~IllrCS, Iiavin~~ ~~I;;cIIII.. cm tlw rhlrcinc fiids, to rutrrlc up; tlw I mC &CJ cu1111cc1ctl 1~p1lwr by hr, or IIIWC, httls, cxtcdiit;: ltrnc 1; th0 \vllOlC length ul’ LIIC asis; hllich, WIICII a1hcbctl tu lhc uu1cr ani. face Of tllc wheels,niav pupcrlv bc c~llcd tlic reel. At 111~ Ii~~~lct aw hxcd four handler 10 &ru tl~c &xl Iq, or it may be turned bv OLIICI m-8; it is lobe suppurtctl by ;L slitlc ill each wtt UC the axis 0; riliirli. wtrich \vorks in 111~ Iuwer e11d of tile sIicIcs, ;UILI can be lowerrtl itld raisCd, at the plcrsurc of the worktncn, d qqor1cd IN pins pssitt:: thy@ the dides in1o cleats UII the surlhcc of tl6 vat; un th* outer wrfucc of each whwl, arc short 1hOn *9 uf lertber. Lrrinrg bWi: ‘heir cads faslcncd bv pinning them into I&s abolll OII(: inch, IllI*r t .

PRILLIPS and MAEE~‘S Catiage &&-: 249 or less, apart: thqe loops pass into holee made in tbe.m,pf t& hides, skins, &c. and the loop pass through each otheb @#ma counexion which keeps the Ldes, skins, &c. to their proper@& or, in lieu thereof, there may be hooks of a curved form, firm1 the hides, skins, or whatever is to be tanned, is to be attache :

fixed9 to -the

surface of the reel, expanded in full width, aupported by the loops or hooks; the hooks to bc used when liming or bating the surface of the reel, may bc fixed from three to six Inches under the liquor; in the process of turning the reel forward and backward, it chariges the position of the hides, Src. in such a munner as to cause’ every part of tile hide to come in contact with the liquor. This machine surpasses all others in its principle of sinking to the bottom of the vat, when left at rest.

WILLIAM BROWN.

SpecQfcation of a patent for ml improvement in the common carriage axle. Granted to DANIEL W. PHILLIPS, of Ikfiiddiebuy, and WIL- LIAM MAHER, of Covington, both in Ccncsee county, in lhe stale of New York, JlpriL23d, 1828. THE principal improvement here intended in the common carri

arle, consists in making the arm, or that part which works in t t e e

nave, of cast iron; to be constructed in the following, or a similar manner.

Each arm of the axle is to be cast with a shank for securing it in the stock, and a wrought iron bar in the centre, projecting a little from the smaller end of the arm, on which is cut a screw to receive a nut for securing the wheel on the asle; the end of the arm iS also a little depressed and squared, in order to receive a fixed collar, or washer, of the same circumlerence with the smaller or exterior box in the nave; after this,,collar is applied, the nut is fi~miy screwedup to it, and as the collar cannot turn on the axle, the nut’is not’&able to come 09 by the uction of the wheel. The shank, whi_& issquare and tapering on the upper side, and of suitable length, IS sunk:mto the under srdc of the stock, or wooden part, which connects-the tti6 arms and forms the central part of the axle, and is secured by bands and bolts.

The benelits.which it is supposed will result from this improve- ment, in the construction of carria made at considerably less expense, t ian those of wrought iron. 2nd. 4

e axles, are, 1st. They can be

Cost iron being harder, and wearin iron, they will be more durable, an1 subject to less friction. T

away much slower, than WL’OU ht Sd. t y

means of the fixed collar, the internal part of the nave is so effcctu- ally closed, that no dust or sand can insinuate itself into it.

DANJEL W. PHILLIPS, \~JLLlAM M~nen.

350 &CEDER’S MCtAOd Of Manufaciuring Carricige Bodies,

d c The figure represents one half of an axle, Cand shows the manner

in which the arms are attached to the stock. A, the stock composed of wood. 13, the arm framed into the stock A, and secured by the bolts

c, c, and a band, seen at d, d. e, a bar of wrought iron, cast into the centre of the arm, and ter-

minating in a screw 1: This piece may extend to any depth.

Speci@cation of an improvement in the mode of making, or manu&-_ tUdng, COr%lge bodies. of ever?! description, and of any requ&-ed ahape. Uenominated Self:bracing Bodies. Granted to J ~~~~ %,EDER, Of Lebanon, Warren county, Ohio, &larch 4th, 1828. 1st. THE skeleton of the body is formed of tou.gh timber, or iron,

made into bows or slats, which, for an ordinary sized coachee body, are about half an inch in thickness, and from a half to an in& and a half in width, when formed of wood, and- of a corresponding strength; when iron is the material employed, these slats (of a length to correspond with the length, breadth, height and shape of the body required) are laid ddwn, crossing each other at right angles in the bottom, at from two to ten inches apart, (according to the degree of strength required,) and are fastened together by rivets, screws, or otherwise, where they cross each other in opposite directions.

2nd. The raves or rails for the seats, ant1 top of this body, being of tough timbers, may be so bent as to constitute, in one piece; the sides and ends of the body, so ;LY to turn the corners with a curve, or with a greater or less angle, as desired ; or they may be joined together in the usual methods at the corners. It may be here recommended:that the bows and rails be steamed, and formed on sets, or moulds, of any desired shape, to suit the fashion of the body intended to be made.

Sd. This skeleton when completed, may be enclosed by boards, or with leatbcr, canvass, or otlier materials in general IN?; suiting the material to the curvature, or shape of the body. Pannels, if de- sired in tile sections of the my, as also representations of a sunken bottom, may be formed of wooden or plated mouldings, or of ally other desired material.

4th. It has been thought necessary by the inventor, in order $ render his explanations more explicit,_to mention irr them, “any the component

E arts of those bodies now it? gen.eral use. .Xy thla lr~

provement, he, owever, claims the sole prior rqht to the d~sco+‘?y~ Invention, and construction ut’ the skdclol%, of his ‘r sclf-braclng

On the Causes which Produce Draft in C&qfiiu; 351

bodies,” by forming them of sh?te of wood or iron, 80 dim,- to extend. in single plecea leugthwlsq the whole length and h&g&$&&. body; 111 the same mgnner extendIn& crosswise; and b&g fartansa together by screws, rivets, or otherwise, where they cme sach o&&

at right angles in the bottom. Also, to his method of binding ti applying the scat and top raves or railS9_ for binding the ends and sides of the slats,. so as to render tile desired shape of the body cm- plek. The particular atlvantageR proposed, in adopting ti con- struction of carriage bodies, are, that they are found to be but of about one-fourth the weight, much stronger, less liable to external in-

1 ‘ury, and requiring not more than one-fourth of the time, manual abour, and expcnsc in matcrlalu, that are necessary to the construe-

tion of any bodies now in genCral USC. JESSE REEDER.

On fhe causes wlriclr llroktce, and the circumstances w*hich o&t, tire IIraft in Chimnies; ~itrtended as an aiiawer to the queries of ‘4 A Citizen of i%w Jersey,” inserted in the Journut of ihe lhnklin huditufefor Alarch, 1829.

TO ~‘BL LDITXIR OF THP JOl!llNAL OF TEL PBAXPLI~ I~STITUTI.

SIR,-I submit for insertion in your Journal, the sub’oined repties to some of the queries of a citizen of New Jersey, w i! in the No. for March.

ich appeared

Yours, &c. MARCUS BULL.

1. Upon what principle does the draft of an air furnace depend? The “draft,” or, more properly, the current o! air through a

chimney, is produced, in consequence of air . \ossesslng th! propefby of expansion when subjected to heat, by whlc

fzfi k?iF”,“,‘d”;herebg becomin f

expaa$ran ltaq~~@, The column of air within the cbimaey,when

w Ii air, it is force: to ascend the chimnby

hter than the .earround’in p the super&

B WTSIUI~~ d) ,

the column of cold air_, and thus the current is ertabtirhe .* 2nd. What Pffect wdl an increased height of the chimney have on

the draft? I’n some cases an injurious, and in others a beneficial effect. The

proper height of a chimney, to’ tion in the furnace, is governed

the mpst powerful combus- particular circymstances. If the

furnace, or receptncle for the be of large dimensions, and ca- pable of producing great heat, and the chimney be constructed of materials which are bad conductors of heat, its hciqht may with act- vantage be greater, than should be the cast if the Lurnace be small,

??Your correapon~lent mny be assured there is no clroiui~ig about the mntlcr, and, although it might sound rather oddly, it would be morccorrrct to ray that a chimney rlricrs, or pusl~cs wll, thpn that il tlrows WCH.