102,111. Short, A. H. May 17, 1916. Holders.-Terminals, shown as plunger cylinders c, are adjustable by screwing within the insulating-body a of a holder so that they can be arranged to prevent insertion or removal of a lamp unless the union ring of the casing is slackened. The spaces of g between the plungers and body may be occupied by hard or soft washers. Conductors pass through notches d in the body to terminals at the upper ends of the plunger cylinders.