This drum has a series of small cogs which move the web or tapes in the same direction.
Wheels creak on their axles as the cogs engage one another and the revolving pulleys whirr with the rapidity of their movement, but a neighboring wheel is as quiet and motionless as though it were prepared to remain so for a hundred years; but the moment comes when the lever catches it and obeying the impulse that wheel begins to creak and joins in the common motion the result and aim of which are beyond its ken.
Separate teeth, fixed into mortises in the rim of the wheel, are called cogs.
The cogs were working behind those blue eyes.
It can seldom be obtained in large portions, and has the disadvantage of being apt to warp; its great hardness, however, renders it valuable for the manufacture of various articles, such as the cogs of mill-wheels, flails and mallets, and handles of hammers.