Page:Miscellaneous Papers on Mechanical Subjects.djvu/153

 cylinder of the carding engine is 36 inches in diameter, and the doffing cylinder 13 inches, the former making 135 revolutions, and the latter seven revolutions per minute. In the fly-frame the front roller makes 200 revolutions per minute, and the flyer from 1,900 to 2,000.

By some shipowners sailcloth made of cotton is preferred to that made from hemp.

Fishing nets made by hand are here also manufactured of cotton.

45. Corn and Flour Mills—Pittsburgh.—These mills employ forty persons, including clerks and all others engaged in the various departments, and are capable of producing 500 barrels of flour per day, each containing 196 lbs.

The grain is brought in bulk in boats alongside the building, and is raised by an elevator, consisting of an endless hand, to which are fixed a series of metal cans revolving in a long wooden trough, which is lowered through the respective hatchways into the boat, and is connected at its upper end with the building where its belt is driven.

The lower end of the trough is open, and as the endless band revolves, six or eight men shovel the grain into the ascending cans, which raise it so rapidly that 4,000 bushels can be lifted and deposited in the mill in an hour.