MECHANICAL AND USEFUL ARTS. 25 



it is stopped off ; during that time it acts by its combustion upon the 

 aii- within the cylinder, and at the same time a part of the rarefied 

 air escapes through one or more valves, and thus a vacuum is 

 effected. The vessel, or cylinder, is kept cool by water. Several 

 mechanical means maybe contrived to bring the above combinations 

 into use in effecting the vacuum with inflammable gas, and on the 

 same principle it may be done in one, two, or more cylinders, or 

 vessels. Having a vacuum effected by the above combinations, and 

 Some mechanical contrivance, powers are produced by its applica- 

 tion to machinery in several ways." Now, Mr. Brown's engine was 

 worked by means of coal gas, the cost of which, at ]s. Gd. per 100U 

 cubic feet, would be 3s. per horse-power per day of 24 hours {i.e., 

 2000 feet of gas) ; this, in London, would be considered an econo- 

 mical power, but (says Mr. Bogers) the gases to which I invite 

 attention are those flowing from the top of blast-furnaces, the cost of 

 ■which may be said to be nil. A furnace taking 5000 cubical feet of 

 blast per minute will yield at least 7,200,000 feet of gases per day, which 

 gases may be applied to work a gas or vacuum- engine with similar 

 effect to the gas from coal. Brown estimated that 1| foot of coal 

 gas per minute, applied in his machine, was equivalent to a horse- 

 power, so that it would, by his mode of working, raise 1 ton of 

 water 224 feet high ; but, in my estimate, I put 3 cubical feet of 

 the blast-furnace gases to effect the same power ; on this calculation 

 the 7,200, 000 feet of furnace-gases, just referred to, would originate 

 a power equal to 1GGG 6-10ths horses working the entire 24 hours of 

 the day. 



Here, then, may be generated a truly gigantic power, from a 

 comparatively waste material at iron-smelting establishments ; it is 

 termed a "waste," because the present arrangement of blast engines, 

 their boilers, fee, may be superseded by water-power machines, that 

 would never be in want of a regular and full supply of water ; and 

 not only may steam-power be dispensed with for generating blast, 

 but also for rolling, hammering, pumping, winding, lifting, stamping, 

 grinding, sawing, crushing, twisting, and pressing operations of all 

 kinds and degrees : the substituted power being waterfalls of 15, 

 30, 45, 00, or more feet, ad libitum, with never-ending supplies of 

 water, both in the summer and winter seasons of the year. There 

 are about 120 blast-furnaces in constant operation in Monmouth- 

 shire, Breconshire, and the eastern parts of Glamorganshire ; and 

 the quantity of blast driven into these furnaces may be fairly esti- 

 mated to average 5000 cubical feet per minute, or an aggregate 

 quantity of SG4,O00,00U feet per day, then, by estimating 3 cubical 

 feet of these gases per minute, or 4320 feet per day, to be the 

 equivalent of a horse-power (Mr. Brown reckoned one foot of coal 

 gas per minute equal to lifting, with his machine, 250 gallons of 

 Water 15 feet high), we have from the 864,000,000 feet of gases the 

 tremendous power of 200,000 horses working constantly for the 24 

 hours of the day, and that in the district of country alone above 

 mentioned. It perhaps maybe said that the gases above referred to 

 are at present used under the blast-engine boilers ; this is true to a 



