One Good Turn: A Natural History of the Screwdriver and the Screw (14 page)

The water screw is not only a simple and ingenious machine, it is also, as far as we know, the first appearance in human history of the helix. The discovery of the screw represents a kind of miracle. Only a mathematical genius like Archimedes could have described the geometry of the helix in the first place, and only a mechanical genius like him could have conceived a practical application for this unusual shape. If he invented the water screw as a young man in Alexandria, and—as I like to think—later adapted the idea of the helix to the endless screw, then we must add a small but hardly trifling honor to his many distinguished achievements: Father of the Screw.

I.
The Archimedean screw continues in use to this day. In modern screw-conveyors, the screw rotates inside the cylinder; in the ancient version, the entire cylinder rotated.

London pattern screwdriver

Scotch pattern screwdriver

Undertaker’s screwdriver

Gent’ fancy screwdriver

Carpenter’s brace

Breast auger

Spiral bit auger

Cooper’s adze

Wooden carpenter’s brace with brass plates

Try square

Bevel

A-level

Spirit level