No. 32.
UNKNOWN LAMP.
(possibly Wood's "REFRIGERATING" LAMP.)
CONSTRUCTION.
Instead of gauze the lamp has perforated copper plate 11/4 ins in height above which is a hollow cylindrical water canister 4 ins high, fitted with water level gauge.
A perforated copper cap covers the top.
This lamp is dismantled by unscrewing the bottom and middle rings.
HISTORICAL NOTE.
Mr. Nicholas Wood, of Killingworth, invented a 'Refrigerating' Lamp, description of which agrees fairly well with this specimen. It was not commonly used. The water jacket was introduced to overcome danger from heating of the lamp.