CHAP. I. COLLIERY MACHINERY. 9 



raised from the pits, and the mines were pumped clear 

 of water, had the effect of directing their attention to 

 the same agency as the best means of accomplishing 

 that object. 



Among the upper-ground workmen employed at 

 the coal-pits, the principal are the firemen, enginemen, 

 and brakesmen, who fire and work the engines, and 

 superintend the machinery by means of which the 

 collieries are worked. Previous to the introduction of 

 the steam-engine the usual machine employed for the 

 purpose was what is called a " gin." The gin consists 

 of a large drum placed horizontally, round which ropes 

 attached to buckets and corves are wound, which are 

 thus drawn up or sent down the shafts by a horse 

 travelling in a circular track or " gin race." This 

 method was employed for drawing up both coals and 

 water, and it is still used for the same purpose in small 

 collieries ; but where the quantity of water to be raised 

 is great, pumps worked by steam power are called 

 into requisition. 



Newcomen's atmospheric engine was first made use of 

 to work the pumps ; and it continued to be so employed 

 long after the more powerful and economical con- 

 densing engine of Watt had been invented. In the 

 Xewcomen or "fire engine," as it was called, the power 

 is produced by the pressure of the atmosphere forcing 

 down the piston in the cylinder, on a vacuum being 

 produced within it by condensation of the contained 

 steam by means of cold-water injection. The piston-rod 

 is attached to one end of a lever, whilst the pump-rod 

 works in connexion with the other, the hydraulic 

 action employed to raise the water being exactly similar 

 to that of a common sucking-pump. 



The working of a Newcomen engine is a clumsy and 

 apparently a very painful process, accompanied by an 

 extraordinary amount of wheezing, sighing, creaking,* 

 and bumping. When the pump descends, there is heard 



