146 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[April, 



and kept free from moisture, it will inescrvu its bulk. From some obser- 

 iiilious of Trcdguld, respecting the earthy impurities and odour of peat 

 ■nheu buriil, it is obvious that he experimented on peats from the lower 

 strata; hut the author, iu opposition lo several eminent philosophers, 

 maintains Ihal turf coke may be made more effective than wood charcoal. 

 The author, iu his fast experiments, came to the same couelusiuns from using 

 Jlie lower though iniimror strata, simply because they were the denser, and 

 rejecting the lighler kinds. The lower strata sometimes contains peal of a 

 tolerable purily. but generally the upper and lighti'r portions are superior 

 in the purily of the carbon, the intensity and qualily of its heal, to those 

 portions which have acquired density by lime and natural pressure. Wlieu 

 ihe density is acquired by artilieial pressure, we have a subslanee superior 

 lo any other for all purposes of metallurgy. 



The diflicidty in the eimversion of turf into coke has liitherto lain in 

 depriving il of its volatile substances so as to make a pure carbon, and in 

 avoiding waste by partial combustion. This is etlected by ,au union of the 

 distillatorv Willi the stilling pr<icess ; the vulalile substances are ex])elled 

 in the oven, and when suftieienlly charred the stifling process is adopted. 

 Turf for the forge must have a greater density than that acquired by this 

 process. This is efl'ecled by pulvei'ising or bruising il, so as to destroy the 

 librous character, and bring the eonipoucnt parts into closer and more per- 

 manent contact. By the union of these processes, any density may be 

 given 10 the fuel which will combine the purity of vegetable charcoal with 

 the density of iniueral coke. The specific graviti(-s of the turf hard pressed 

 (water being lUOU) is IKiU — of the coke from the hard pressed 1010. 

 Thus, the hard pressed turf is denser than the densest wood, and the turf 

 coke double the density of charcoal and equal to coal coke. 



The lest adopted by Ihe author, after Berthicr, of the calorific power, or 

 relative power of absorbing oxygen, is Ihe quantity of metallic lead re- 

 duced from its slate of oxide by giving weights of the several fuels. Pure 

 carbon gives 310 grains, wood charcoal 307, turf coke 277, best coal 

 coke 277. 



Thus we have a measure of the relative quantities of heal ; but in- 

 tensity of lieat is often of more consequence than quantity, and intensity 

 depends on the density of the fuel. Berthier remarks that the superiority 

 of coke to wood charcoal is ow ing lo its density. In the above com- 

 jiariaon, no account is taken of the impurilies uf the fuels; consequently, 

 turf coke, being free of sulphur, has great advantages. The author finds 

 that iron worked with turf coke is sooner brought to a welding heat, works 

 softer, and comparatively free from scales. 



The author then describes Ihe resin fuel as an artificial coal produced by 

 imitating the process of nature, in the best combinations peculiar to coal. 

 Natural pit coal consists of bituminous, carbonaceous, and various foreign 

 ingredients, of which sulphur is in abundance, and very injurious. The 

 i-esin fuel consists of resin, the purest available bilumen, and turf coke, the 

 purest vegetable carbon. Thus, the greatest heating power exists iu the 

 smallest bulk, and the excess of bitumen and delieiency of carbon, as in 

 cannel coal, or excess of carbon and deficiency of bitumen, as in an- 

 thracite, may be avoided. Hesin, nolwilhslandiug its price, is used in 

 steam navigation, but very disadvantageously, in combination with cinders, 

 as il melts and passes oil' iu a state of vapour, not entering readily into 

 combustion with Ihe oxygen of the atmosphere. But iu the resin fuel, in 

 consequence of the extraordinary allraetion which subsists between carbon 

 and oxygen, Ihe resin has ils full combustible and calorific efl'eet. In 

 the furnaces of boilers, a solid cinder is requisite, v\hicli may be pro- 

 duced by adding some of tlie inferior bilumen, as pitch and tar. The 

 fuel is manufactured by adding turf coke, in a state of powder, to Ihe 

 bitumen in a melting stale, and in .such quantities as lo saturate each 

 other. The average price of the fuel is .30s. to 40s. per Ion. Its use was fully 

 tested in the voyages of the Hoyal William, in which 20 cwl. of coal, 

 with 2 cwl. of the fuel, did the work of 2G cwt. of coal. The suddenness 

 of the action and the great increase ol' lieat for a small increase in its con- 

 fciimption, render it of great value in cases of emergency. The author 

 concludes by expressing his conviction, afler ten years' experience, Ihat 

 the turf bogs of Ireland may be rendered available for many important 

 uses in the arts. 



Feb. 10. — The President iu the chair. 



The following gentlemen were elected: — J. A. Galloway, as a Member; 

 E. Birch, as a Graduate; G. Moore, C. Robinson, and S. Keed, as Asso- 

 ciates; and Captain Sir E. Parry, as an Honorary Member. 



" On Railways in America." Communicated in a letter to the President. 

 By S. W. Roberts. 



The writer describes the various melbods which had bsen adopted of 

 laying down Railways in America dui ing Ihe last twelve years. First, limber 

 vails with light flat iron bars were tried; these were found cheap, but not 

 durable. Next, stone rails, or sills similarly plated. Next, heavy iron rails 

 laid on blocks of stone; the violent vicissitudes of Ibe seasons soon deranged 

 the foundation of these, and caused the track to spread. The heavy iron 

 rails were next laid on a foundation of timber. The Alleghany Portage 

 Railroad was laid four years ago by the writer wiih hewn while oak timber, 

 10 inches square, imbedded in the ground ; upon these cross sills of locust 

 timber, by eight inches, and 7', feet long, notched and Ireuailed. On the 

 topof these cross sills, and directly over the longitudinal timbers, the cast- 

 iron chairs which supported the rails were boiled. The track was thus 

 efTectually prevented from spreading. The rails are from 45 to 60 lbs. per 

 yard, from 3 lo 3J inches in height, and from ;i^ to 4^ inches on the base. 

 On roads with difficult curves " bogie" engines are used. Each locomotive 

 has six wheels. The hinder part is supported by a pair of driving wheels. 



4 to 5 feet in diameter, and the front part rests upon a bolster on the bogie, 

 which has four wheels of about 33 inches diameter. Each passenger car is 

 30 feet long and holds fifty persons, and warmed by a stove. The long cars 

 are adopted as less likely to upset than those on six wheels. The average 

 speed, including stoppages, is \G miles per hour. 



" Manchester and Leeds Railway Section." Bv Francis Wbishaw, M. 

 Inst. C. E. 



This section, prepared under the direction of Mr. Whishaw, is designed 

 to aflbrd a novel and useful method of embodying a great mass of the 

 details required by an engineer when giving evidence before a P,arlia- 

 mentaiy Committee. This seclicn was constructed before the last standing 

 orders, and the author had here anticipated them in putting uptm this section 

 much of the detail now required. By sections thus prepared the engineer 

 can always answer any questions which may be put to him. 



" Account of Boring for Water through Granite." By Frederick Holland. 

 Communicated by Apsley PellatI, A. Inst. C. E. 



A hole, 6 feet wide and 7 feet deep, was first dug, and a wooden cylinder 

 lined with bricks inserted. Two pieces of cast-iron pipe, G feel in length 

 and 8 inches in diameter, turned smooth at both ends, and united by a 

 wrougbt-iron hoop ring, so that when the whole number of pipes were 

 driven, a continuous pipe, peifectly cylindrical, both on the inside and on 

 llie out, was formed. Nine lengths of pipe were connected and driven, and 

 then the boring commeueed, and continued through a harJ rich species of 

 rock or granite, having all the component parts but not the compactness of 

 granite. The boring was continued to a depth of 175 feet. The supply 

 has been regular at the rate of from 48 to 50 gallons per minute, a tem- 

 perature of 48" F., the external air being 52J° F. 



Mr. Brunei staled, that Ihe advance of the Thames Tunnel was now at the 

 rale of 3 feet per week ; they were now 04 feet from low-water mark. He 

 presented some specimens of sand, which, when mixed with a certain quan- 

 tity of water, was exceedingly troublesome. They frequently push the 

 poling boards iiefore them : last night not less than (JO square feet was 

 pushed before them. They fight their way on with diflSeully, but con- 

 tinuou.sly. 



Fell. 26. — The President in the chair. 



The following gentlemen were elected: — G. Grove, .T. B.Redman, as 

 Graduates ; S. M. Peto, T. Grissell, .and Rev. S. King, as Associates. 



" On the Economy of working expansively in Crank Engines." By John 

 Watt. 



A letter from Mr. Watt was read on the economy produced by working 

 steam in large sleam engines ex'pansively, in which the author details the 

 result of some experiments on a high pressure engine, employed for blowing 

 furnaces. The steam cylinder of the engine in question was 33 inches in 

 diameter, the blowing cylinder 122 inches, length of stroke 9 feet, pressure 

 on the piston 41 lbs., and iu the boiler 4.5 lbs. per square inch, the number of 

 strokes about 12 per minute, and the pillar of blast 2J. A large fly-wheel 

 was attached, and on fitting the steam engine with an expansive apparatus 

 and culling oft' at half stroke, the performance was greater than at any pre- 

 vious time, with a saving of 25 per cent, of fuel. The author refers this to 

 the fact, that all the moving parts, with the exception of the fly-wheel, are 

 brought to a slate of rest at Ibe conclusion of each stroke, and that if the 

 steam be allowed to enter throughout the whole length of the stroke, Ihe pis- 

 ton will have lo draw from Ibe fiy-wbeel momenlum sulficieni to overcome 

 its own momentum, and lo alter the direction of ils reciprocating parts; but 

 the steam being cut otf so that the momentum be destroyed by the lime the 

 piston terminates its stroke, the return stroke will be commenced without 

 checking the unnecessary impetus which exists when the sleam is admitted 

 to the end of the stroke. Thus it is observed, that engines working expan- 

 sively pass the centres more easily than when working full pressure tlirough- 

 oiit the stroke. The momentum which has lo he destroyed is created at the 

 expenditure of more than half a cylinder full of steam ; and the checkingthis 

 motion is also accompanied by a still further waste of steam. Mr. Watt had 

 altered an engine driving rolls for rolling iron, and the result of cutting off at 

 half stroke was here also attended with a saving of 25 per cent, of fuel. 

 March 5. — The President in the chair. 



The following gentlemen were elected : — Thomas Chalmers, Andrew Burn, 

 as Graduates ; and .lobu William Lubbock, as an Honorary Member. 



" On the Comparison between the power of Locomotive Engines, and the 

 cft'ect produced by that power at diflferent velocities." By Professor Bailosv, 

 Hon. M. Inst. C.E. 



In this paper Ihe author does not attempt lo explain an exact method for 

 compuling the power of locomolive engines, hut only one tolerably approxi- 

 mate. The melhod he pursues is this: — " If we know e.Nperimentally the 

 number of cubic feet of water evaporated in any given lime by an engine, 

 Ihe space passed over in that time, the length of stroke and the capacity of 

 the cylinder, we hence know how many cubic feet of sleam have been em- 

 ployed, and, consequently, the mean number of cubic feet of steam produced 

 from one cubic foot of water: hence, again, by experiments that have been 

 made by difterent writers upon the power of steam, we know the pressure 

 per inch on the piston, and then making due allowance for the resistance of 

 the atmosphere on the piston, the friction of the engine-gear, &c., we have 

 loft the force that ought lo be eftective. And this being reduced to the cir- 

 cumference of the wheel, it should be equ.il to the resistance opposed by the 

 load, which, on a level plane, consists of axle friction, road resistance, and 

 Ihe resistance of the atmosphere to the engine and carriages. But this is 

 assuming a perfect action to the engine without any waste, which, though 



