THE STEAM-ENGINE. 115 



follows : Cylinder thirty inches diameter, stroke in the cylin- 

 der and in the pump six feet, fifteen strokes per minute, and 

 depth of pit 267 feet. The pumps were seven inches in 

 diameter, twenty-four feet apart, and pumped from cistern to 

 cistern, from the bottom to the top. The boiler was nine 

 feet diameter, three feet deep in the body part, and on the 

 top there was a curious precaution, namely, two feet six 

 inches of masonry to keep that top from being lifted by the 

 pressure of the steam. There were to this engine, gauge- cocks, 

 a safety-valve, and the injection into the cylinder of those 

 clays Newcomen's injection, and a piston kept tight with 

 leather packing with water on the top. The result of the 

 erection of this machine was, that whereas previously fifty 

 horses and twenty men had been employed day and night 

 continuously to keep the colliery free of water, when the 

 engine was completed forty-eight hours of its work unwatered 

 the colliery for a whole week, it requiring only one man 

 on guard to attend to it. Having described this machine 

 in the most detailed manner, Belidor breaks out into a rhap- 

 sody upon it, which being roughly translated is to this effect : 

 "It must be acknowledged that here is the most mar- 

 vellous of machines, and that there is nothing in mechanism 

 which relates so nearly to animal life. Heat is the principle 

 of its movements, there is passing in its different tubes a 

 circulation like that of the blood in the veins ; it has valves 

 which open and shut at the proper times, and it performs all 

 the functions which are necessary to keep it in existence, and 

 to derive from its work all that possibly can be desired." I 

 think those enthusiastic remarks of the excellent writer Beli- 

 dor, in 1737, are as applicable at the present time as they 

 were then, for although the machine is no longer a matter of 

 novelty, and we have got used to it and to its benefits, as we 

 have to those of light and air ; and have thus lost the very 

 appreciation of the existence of its benefits, as we have those 

 derived from light and air, until from some cause they are 

 forced upon our notice. We must, nevertheless, when they 

 are forced upon our notice, agree with Belidor that there is 

 not any machine the product of the intelligence of man 

 which is more worthy of our consideration and commen- 

 dation than is the steam-engine. 



Of the Newcomen engine I have a model here, lent by the 

 Council of King's College. This is such an engine as 



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