The piston rods are formed with conical ends for fitting into the piston, but are coned the reverse way as in locomotives, and are secured in the piston by nuts on the ends of the rods, these nuts being provided with ratchets to prevent them from unscrewing accidentally.

Then, before his very eyes, and long ere he could unscrew the metal stopper, he saw the contents of the closed glass phial sink and lessen as though some one were drinking violently and greedily of the liquor within.

And when she had sufficiently crushed the letter-book in the press, she lovingly unscrewed and drew forth the book; and with solicitude she opened the book on the smaller table, and tenderly detached the blotting-paper from the damp tissue paper, and at last extracted the copied letter and examined its surface.

The holding cap must have been partially unscrewed.

Then the labourer, regardless of the danger he was running, unscrewed his helmet, into which fresh air was being pumped, and, placing it quite near his fallen comrade, enabled him to get some of the air.