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I fasten a horizontal board in the frame RR of my rotatory apparatus, lie down upon the same with my right ear upon the board, and cause the apparatus to be uniformly rotated.

Screw and Screw-back.—This is putting a rotatory motion on a ball, causing it to spin on a horizontal axis backwards.

Campbell and Moore have found spectroscopic evidence of internal rotatory motion in a large proportion of the planetary nebul�.

They exhibit rotatory or oscillatory movements, especially observed when a drop of water is added to the fluid.

The earth’s rotation is the original source of the rotatory movements, but both intensify the initial motion.