THREE:For a half century past no considerable change has been made in engine lathes, at least no new principle of operation has been added, but many improvements have been made in their adaptation and capacity for special kinds of work. Improvements have been made in the facilities for changing wheels in screw cutting and feeding, by frictional starting gear for the carriages, an independent feed movement for turning, arrangements to adjust tools, cross feeding and so on, adding something, no doubt, to the efficiency of lathes; but the improvements named have been mainly directed to supplanting the skill of lathemen.Charlton said nothing, but from the sound of his laboured breathing it was evident that the spirit of adventure was upon him. They sat there for some time with the two doors open, so that they might see through the grimy windows into the courtyard beyond. It was weary work, and the minutes passed slowly.