SECT. I.] 



THE STEAM ENGINE. 



making a constant fire under it ; within twenty-four hours it burst and made a 

 great crack ; so that having a way to make my vessels so that they are strengthened 

 by the force within them, and the one to fill after the other, I have seen the water 

 run like a constant fountain stream forty feet high. One vessel of water rarefied 

 by fire driveth up forty of cold water. And a man that tends the work is but to 

 turn two cocks, that, one vessel of water being consumed, another begins to force 

 and refill with cold water, and so successively, the fire being tended and kept 

 constant ; which the selfsame person may likewise abundantly perform in the 

 interim between the necessity of turning the said cocks." 



This description puts it beyond a doubt that the Marquis of Worcester knew that 

 steam, heated in a close vessel, acquires an immense degree of force, and that this 

 force could be effectively applied to raise water. The effect of condensation he does 

 not appear to have been at all acquainted with, and therefore his mode of operation 

 must have been exceedingly simple, and probably, of the nature exhibited in the 

 annexed figure : where B is the boiler ; C, one of the vessels with a pipe to deliver 

 the water to an elevated cistern D. 



FIG. 1. 



Now suppose the vessel C to be supplied from a cistern of cold water A by a pipe, so 

 that it would be filled on opening the cock E, and afterwards closing it ; if, when 

 the steam in the boiler is of sufficient strength, the cock F be opened, the pressure 

 of the steam on the water in C would cause it to ascend from C, through the pipe a 

 into the cistern D. The vessel C being emptied, and the cock F being shut, it would 

 refill with water on again opening the cock E. Another vessel C, and its cocks and 



