Safety lamp, Davy with glass shield no.5, from the Royal Commission on Accidents in Mines 1879-86, marking: C.T. and Co., 1850-1880

This is a standard Davy lamp with the addition of an external glass cylinder, a type which has been in use in the North of England since about 1850. The glass extends 0.5 in. above the lower edge of the gauze cap, and is supported by four metal pegs on the reservoir, leaving a space of 0.125 in. for admission of air In the Commissioners ' experiments it successfully resisted an explosive mixture whose velocity was 1,200 ft. per min. A lead plug lock is fitted.