231,162. Kral, L. March 19, 1924, [Convention date]. Magnesium lamps.-A combustible element is composed of a number of superposed magnesium plates or discs 2 spaced apart either by central projections or by smaller plates 3 composed of oxygen-yielding material such as the oxides or peroxides of alkaline earths or heavy metals or of indifferent material such as magnesia usta. The element may be burnt in a lamp consisting of a closed cylinder 1 fitted with valve-controlled pipes 8, 9 for supplying oxygen or a mixture of oxygen and air and for exhausting the combustion products. A nozzle 11 is arranged in the pipe 8 to prevent appreciable variation in the supply pressure. The rate of combustion may be regulated by varying the pressure of the oxygen or oxygen and air in the cylinder 1 by adjustment of the valve in the pipe 9. The plates 2 are ignited by means of a quick-match or fuse 5 which passes through a tube 4 on which the plates 2, 3 are mounted, and protrudes through a cock 6 at the base of the cylinder 1. The cock 6 is closed by a spring 7 as soon as the fuse 5 is burnt through. A reflector is arranged behind the cylinder 1. A number of combustible elements may be arranged in a single cylinder 1 or a number of cylinders may be connected to common gas supply and exhaust pipes.