Abstract: A device for feeding measured amounts of alumina to the break in the crust on an electrolytic cell is such that in a stationary channel there is a transporting facility which is connected to a power drive facility and to an alumina silo. The channel is a feed pipe for a piston arrangement which is situated under an inlet opening from the silo and features at least one opening or chamber as a space for a limited amount of alumina to be fed to the cell. This space is delimited by a blocking piston and a feed piston. The width of this space can however be varied and, if desired, can correspond to the width of the inlet opening and an outlet opening which is laterally displaced with respect to the inlet.If more feeding chambers are desired, these are formed by a plurality of blocking pistons and feeding pistons. The piston arrangement is connected via rods to a, preferably pneumatic, power drive and can be moved back and forwards.