482 JAMES WATT. 



as a motive power ; but we have yet to learn that that power 

 was ever applied by him to the organic parts of an engine, 

 calculated to overcome the resistance of a load, such as the 

 propulsion of machinery or the raising water from mines. 

 The discovery of an element of power is a totally different 

 thing to its application through the organic parts of a machine. 

 The first is the result of experimental research in the labora- 

 tory ; the second is the result of toilsome labour in the work- 

 shop, in the actual production of a machine ; merit for the 

 former belongs to Dr. Papin, for the latter, exclusively to 

 Newcomen and James Watt. 



Savery constructed an engine for raising water upon the 

 principle of condensation. It consisted of two vessels, a 

 boiler and a condenser, if we may so term them, the latter 

 being connected by pipes with the water in the mine and the 

 reservoir to which it was to be raised. Under the boiler a fire 

 was lighted, and the steam was allowed to fill the condenser ; 

 the connection with the boiler was then cut ofi, and a jet of 

 cold water thrown into the condenser, which at once created 

 a vacuum ; the pressure of the atmosphere now forced the 

 water from a depth not exceeding 30 feet in the mine, into 

 the condenser, where it was retained by a valve. Steam from 

 the boiler then forced the water from the condenser upwards 

 through the pipe to the reservoir above, and as soon as it was 

 again filled with steam, the process was repeated. This slow 

 and tedious operation was regulated by hand, but that could 

 only be done under the limits stated above, and with an enor- 

 mous consumption of fuel. This was the apparatus adopted 

 by Savery, but we have no satisfactory information that Dr. 

 Papin ever constructed an engine worked by steam ; his at- 

 tempts were made on models which were never usefully 

 applied; and Dr. Hooke, in his correspondence with New- 

 comen and the Royal Society, pointed out the absurdity and 

 fallacy of the air-pipes and pistons, which he proposed as a 

 means of raising water from mines. The only real inventor, 

 antecedent to Watt, was Newcomen, who introduced the open 

 top cylinder, and the reciprocating motion of the piston and 



