Similar to a single-cleat ladder, but wider, with an additional center rail which allows for two-way traffic of workmen ascending […]

A church constructed in two stories, affording two places of worship, one above the other; a large hole in the

Same as repeating theodolite.

In electric wiring, a switch which opens a conductor at two points.

The edge of a door (along the lock stile) which is beveled from the center of the edge toward each

In plumbing, an Sshaped pipe fitting.