I7fi 



THE CIVIL ENGlNEEll AND ARCHITECTS JOURNAL. 



[May, 



Hiiplictl first to one of his Smilliamplon coaches, and aitcrvcanls to the 

 ShrcHshiiry coach, anil in hoth cases with the greatest .success. The j.rin- 

 ciple of the invention is pressure so applierl to the nave of the wheel as tu 

 retard i Is motion, or at the will of the coachman stop it altogelhcr. The 

 advaiita^'es ol the invention are, that the power may be applied at the dis- 

 cretion of the coachman, so that he mi^lit take his coach down a steep liill, 

 V ilhout allowing his horses to be pressed upon .It all. This invention reflecls 

 p-eat credit upon ^Ir. .learrad, and we hope it will he extensively applied to 

 imr four wheeled carriages, for it will contribute materially to the safely of 

 the public. — Cheltenham Jotiritdf. 



Piirrelfihi Letters. — A patent has lately been taken out for an invention to 

 supersede the ordinary wooden letters usvially fixed upon the facia of shop- 

 windows. The new letters arc made of porcelain, of every fonn and hue, 

 and when fixed up, present a beautiful and atlraclivc appearance. The fa- 

 cility of cleansing them is not the li ast of their qualiriealions ; for with a 

 sponge Ihey are immediately brought to their pristine beauty and elegance. 

 It is staleil'lliat they will not exceed the old wooden letters in price. .Some 

 of the patterns are very elegant, particularly the golilen ones, and, being 

 glazed, present a dazzling and animated appearance. They are luit quite 

 really for public use, but it is expected they will soon arrive from the manu- 

 laclory in .Stalfordshire. 



A'l H' Fuel. — The Rev. Mr. C'obbold lias invented a fuel composed of peat 

 and tie eommr.n refuse of gas tar, which hums with a bright flame, little or 

 no smoke, and gives out an intense heat. It has no smell whatever, and has 

 been tried in a grate, in comparison with coal. According to this experi- 

 iTH'iit. which was made by a chemist, but without weighing the fuel, two 

 i|uarls of water were evaporled in 3-J minutes, leaving a good fire after- 

 w.irds ; while with Newcastle coal it took ol minutes, leaving a low, burnt- 

 out fire. Mr. C'obbold says he can render this fuel at 7s. per ton. — RaUwntj 

 MaiTttzhie. 



.1 Xeie am! Effeeliial Method to Kyntiise Timber .—'WW^nn the last two or 

 three weeks the Mancliester and Birmingham Railway Company have com- 

 menced Kyanising their wood sleepers in a much more quick and eflectual 

 < manner than by the old mode of simply dcpo iling the timber immersed in 

 the prepared liquid. The company liave had made a large iron cylindrical 

 vessel, weighing about ten tons, .and w hich is about thirty feet long, and six 

 or seven feet diameter, made from wrought-irun plates, five-eighihs tliick, 

 and ikuble rivetted, which vessel is capaUe of resisting a pressure of 250 lbs. 

 on the inch. 'Jhe vessel being filled as compactly as po.-isible with wood 

 sleepers, twelve inches broad and seven inches thick, Ihe liquid is then forced 

 in w illi one of Brainah's hydraulic pumps, and w nrked by six men to a jiressure 

 of 170 lbs. on the inch. B'y this means the timber is completely saturated 

 througliout in about ten hours, which operation, on the old system, took 

 some months to eifect. 



E.rtranrdhiari/ Maimer of Mamjaeturin^ Cloth.— k gentleman, residing at 

 piesent in London, has just obtained, we are told, a patent for making the 

 finest cloth lor genllemen's coats, &c., without spinning, weaving, or indeed 

 without the aid of any machinery similar to those processes, and at a cost 

 less than one-fourth the present price. The most extraordinary circumstance 

 in this contrivance is, that air is the only power used in the manufacture of 

 llie article. The ingenious inventor places in an air-tight chaml«r a quantity 

 of flocculent particles of wool, whicli by means of a species of ninnowing- 

 H heel are kept floating equally throughout Ihe atmosphere coutair\,ed therein ; 

 (m one side of the chamber is" a net work of metal of the finest manufacture, 

 which communicates with a chamber from which the air can be abstracted by 

 means of an exhausting syringe. comm(mly called an air pump, and on the 

 commLinicalion between the chambers being opened the air rushes with ex- 

 treme vehemence to supply the partial vacuum in the exhausted chamber, 

 carrying the wholly I'occula against the netting, and so interlacing the fibres, 

 that a tdoth of a beautiful fabric and c'ose texture is instantaneously made. 

 Several of the specimens of thi.i cloth that h.ive been shown to scientific gen- 

 tlemen and manufac'-urers have excited great admiration. This cloth is a 

 species of felt, but instead of adopting the old laborious method, the above, 

 which is denominated Ihe pr.esmatie process, is used, and produces the result 

 ;is it were by magic. — Observer. 



ON THE CONSTRUCTION OF LIME KILN.S. 



EV Sm f. G. STf.^RT MENTEATU, tlARt. 



Havino been engaged in burning lime for the supply of an exten.-ivc dis- 

 trict of country for agricultural improvrments, and being distant from coal 

 IH miles, it was desirable to find out the. best construclcd kiln lor l/urning 

 lime with the smallest quantity of coal, and having been aware from experi- 

 ment that the kilns generally employed in l.'rcat Britain lor burning lime are 

 of a construction too narrow at bottom, and too wide at lop. many kilns of 

 this construction being not more than three or four feel » ide at bo'ti m, and 

 18 feet v.'iile at the height of 21 feet, were found to waste ihe fuel during the 

 process of calcining the lime, or in other words, tlid not pioduce more than 

 two measures of burnt lime f hells for one measure of coal ; but it is to I.e 

 understood, that in whatever construction of kiln lime is burnt, ihe fuel 

 required to I urn limestone must vary according to Ihe softness, (.r hardness, 

 or density of the slone, and the quality or strength of the coal used. The 

 same measure of coal in .Scotland called chews, when employed, will burn 

 A greater quantity of lime in a given lime llian the same ijuanlity or weijiht 

 of small coal, the chews or small pieces (if coal admitling the air to circulate 

 more freely through the kiln. Though this fact should be well known to 

 limc-burncrs. yet ihey frequently cmpl(jy sm.all coal in burning lime, from its 

 being procured at a less price, llioneh really a.t a gi'calcr exper.ce, as it re- 

 quires a mueli larger quantity to produce Ihe same cllecl. anil a longer time 

 to admit of eL|ual (iuantiiies of lime being drawn out of the same kiln in a 

 given time. 



For a sale of lime for agricultural purposes in a limited district, i have 

 found kilns of small dimensions to he most profitable; the construction of a 

 kiln 1 have employed for many years was of an oval shajje, five feel wiile at 

 boltom, widening gradually to six feet at the height of IRfeet, and continu- 

 ing at that width to 28 feet high from the bottom. A kiln of this construc- 

 tion has been found to burn lime in much less time, and with a smaller pro- 

 portion of fuel, than kilns of large dimensions, narrow at bottom and wide 

 at top, .as heat is well known to ascend more rapidly in a perpendicular than 

 in a sloiiing direction, from which arises the superiority of a narrow kiln, 

 with si<les nearly perpendicular, compared with one with sides that slope 

 rapidly. 



Those narrow kilns will admit of being drawn out of them every day. if 

 fully employed, more than two-thirds or nearly three-fourths of wliat they 

 contain, of well burnt lime, and all'onl fully three of lime-shells fnr unc 

 measure of coal, when large circular kilns will not give out more than one 

 half of their eontenis every day. and require nearly one of coal for every two 

 measures of lime burnt. In a country sale of lime, the quantity sold every 

 d.ay is liable to great lluctualions : two u\ three cart loads will sometimes 

 only be rei^uired from an eslablishmeut which, the day before, supplied 

 forty ; .and as lime is known to be a commodity, when exposed to the aclion 

 of air, which becomes more bulky and heavy, and in that state dues nol ad- 

 mit of being carried to a distance without additional labour, it has been an 

 olijcct of importance with me to find out a construction of a kiln which will 

 allow of lime being kept for several (bays without slacking, and at the same 

 lime to prevent the fire escaping at the lop of the kiln, if the kiln stands 24 

 hours H ithout being employed, especi.'iUy ciurirg the .autumn and winter when 

 the air is cold and the nights long. I now employ kilns of an egg shape, and 

 .also oval ; the oval-shaped kilns are divided by arches across the kiln, des- 

 cending four feet from the top : the object of the arches across the kiln is to 

 prevent the sides of the kiln falling ill or contracting, and .also to enable you 

 to form circular openings for feeding in the stone and coal at the moulh of 

 the kiln ; upon this plan, a kiln of any length miglit be constructed willi 

 numerous round mouths. From the great expense attending the driving of 

 fuel from a distance of 25 miles from my own coal-pits, I have iulopted the 

 practice of cokeing the coal, which is a saving of two-fifths of the weight, 

 and I find that an equ.al measure of coal and ciike have the same (juautity of 

 heat in burning lime, which is somewhat paradoxical, but not the less true. 

 Tlie coal is found to have little cllect upon the stone till it is deprived of its 

 bitumen, or is coked in Ihe kiln ; for, during the time the smoke is emitted 

 from Ihe top of a lime kiln, little or no heat is evolved ; or, in other words, 

 does not the smoke carry olf the heat, which is not given out from the smoke 

 till if is inllamed, which does not take place in Ihe ordinary lime ki'ns ? A 

 kiln in which coke is the fuel employed will yield nearly a third more lime 

 shells in a given time than when coal is the fuel, so that coke may be used 

 occasionally when a greater quantity of lime is required in a certain tunc 

 than usual, as it is well known to lime burners that the process of burning is 

 done most economically w lien tj)e kiln is in full action, .so as almost constantly 

 to have a column of fire from the bottom to the top of the kiln, with as short 

 intervals as possible in working the kiln. 



Having found that limestone is apt to be vitrified durin.g the process of 

 enVination during stormy weather, from the increased circulation of air 

 through the kiln, whicli adds much to the heat derived from the fuel cm- 

 ployed, and w hich experienced lime-burners would have diminished could 

 they be aware at all times oi an occurrence of this kind : from having expe- 

 rience of the bad ellecls of too great a circulation without properly provi ling 

 against it, 1 have reason to believe that by having a power to ihiow in at 

 pleasure an additional quantity of air into the bottom of a lime kiln, a con- 

 sideraWe saving of fuel necessary for the ca'cination ol lime would lake 

 ))Iace, and another object Would be gained, that of cooling Ihe limestone in 

 the bottom of the kiln, which frcqueiuly retards the drawing out of the burnt 

 limestone for some hours, or until the 1 mestonc is so cold as not to burn the 

 wooden structure of carls. 



In working a kiln w illi narrow circular mouths, th:' slonc and coal should 

 be earefu ly measured, so that ihe workmen can proporlion the fuel employed 

 to Ihe qua-nlity of stones, and it is obvious, that the quantity of coal to he 

 used must depend upon its relative quality, .and the hardness of the stone to 

 le burnt. If this measure was adopicd in kilns of any construction, the lime 

 shells would be found bolter burnt. — Ttie TJubl'm ,'ldfertiser. 



STEAM NAVIGATION. 



The Presidtnl Steam Ship.— 'I'hh vessel, tlie largest ever yet built, arrive,! 

 here a few days ago under Ihe command of Captain Kean, and is now lying 

 in Sloyne. .'^he is an exceedingly beautiful moilel ; built of the best material 

 that England and England's wealth can sujiply, and is in every respect a 

 nob^e vessel, ."^he is now, (her engines not being yet on board,) what is in 

 nautical term, called '■ light" ; and loomes very large. Her proportions are, 

 however, such but for the comparative size oT the Queen's mail ships near 

 lier. she is so compact lluil she does not appear at even a short distance to 

 be larger than the " Ijiverpool." A nearer approach, however, undeceives 

 the beholder, and a visit on hoard, realizes to 'Hn fullest extent Ihe concep- 

 tion of" a wooden world." 



She is painted in man-of-war style, with gun ports, and is liandsomely 

 rigged as a three-masted schooner, with a foremast, forctopmast, and topgal- 

 lanlmast, approximating to those of a ship. Her how is fine, and at the ex- 

 trimily of her hcadrails will be placed, when completed as a figure-head, a 

 liust of ^Vashinglon, the hero of American independence. Her stern is pro- 

 jective, beautiiully formed to turn ofi' a heavy sea ; ornamented aloft w ith the 

 arms of England and America, quaitered iu heraldic shield, supported by 



