Early industrial vintage solid brass lamp with an adjustable clamping base. This lamp is marked Buss Clamp-O-Set on the base and Paiste on the brass socket. It measures about 6 1/2" high and the base is threaded to clamp onto a table, shelf, bed headboard etc. up to about 2.5" thick.
The vintage Edison Mazda light bulb shown in the photos IS NOT included with this lamp. However, reproduction Mazda light bulbs are readily available online. Just try searching reproduction mazda light bulb.