It was here that, on his invitation, James Watt constructed a model of his steam-engine, which was tested in a now disused colliery.
It should be noted, however, that with an icemaking plant of moderate size and a steam-engine of good construction the weight of steam used will not neatly equal the weight of ice produced, so that the difference must be made up either by distillation, which is a costly process, or by ordinary water.
When it is connected with a continuously turning piece (such as the crank of a steam-engine) the ends of the stroke of the reciprocating piece correspond to the d.ead-points of the path of the connected point of the turning piece, where the line of connection is continuous with or coincides with the crank-arm.
The steam-engine first took the place of horses as a threshing power in 1803, but it was not until after 1850 that it was applied to the plough and cultivator.
The total heat with which we are actually concerned in the working of a steam engine is the total heat as here defined, and not the total heat as defined by Regnault, which, however, differs from (E+pv) only by a quantity which is inappreciable in ordinary practice.
