ONE:This method of treating the subject of motive-engines will no doubt be presenting it in a new way, but it is merely beginning at an unusual place. A learner who commences with first principles, instead of pistons, valves, connections, and bearings, will find in the end that he has not only adopted the best course, but the shortest one to understand steam and other expansive engines.
THREE:Upon entering the shop, a learner will generally, to use a shop phrase, "be introduced to a hammer and chisel;" he will, perhaps, regard these hand tools with a kind of contempt. Seeing other operations carried on by power, and the machines in charge of skilled men, he is likely to esteem chipping and filing as of but little importance and mainly intended for keeping apprentices employed. But long after, when a score of years has been added to his experience, the hammer, chisel, and file, will remain the most crucial test of his hand skill, and after learning to manipulate power tools of all kinds in the most thorough manner, a few blows with a chipping hammer, or a half-dozen strokes with a file, will not only be a more difficult test of skill, but one most likely to be met with.
THREE:Another difference between solid and expanding dies, which may be pointed out, is in the firmness with which the cutting edges are held. With a solid die, the edges or teeth being all combined in one solid piece, are firmly held in a fixed position; while with expanding dies their position has to be maintained by mechanical devices which are liable to yield under the pressure which arises in cutting. The result is, that the precision with which a screwing machine with movable dies will act, is dependent upon the strength of the 'abutment' behind the dies, which should be a hard unyielding surface with as much area as possible.
THREE:Maitrank chuckled. He admired a fighter, and here was one to his hand. It was pretty audacious in a woman who had swindled him out of a fortune.