He thenceforward devoted himself entirely to mechanical pursuits.

Mr.Buckle has said of him:--"The rising sun often found him, after a night spent in incessant labour, still at the anvil or turning-lathe; for with his own hands he would make such articles as he would not intrust to unskilful ones." In 1799 he took out a patent (No.

2340), embodying some very important inventions.

First, it included the endless screw working into a toothed-wheel, for boring steam-cylinders, which is still in use.
Second, the casting of a steam-jacket in one cylinder, instead of being made in separate segments bolted together with caulked joints, as was previously done.

Third, the new double-D slide-valve, by which the construction and working of the steam-engine was simplified, and the loss of steam saved, as well as the cylindrical valve for the same purpose.