Abstract: A metering apparatus for liquids containing granular solids, in particular lapping liquid. The stream of liquid issuing from the feed pipe is conveyed with a wide area against a substantially vertical wall, to run down thereon in the form of a thin film of uniform thickness. The collecting pipe is arranged on the side of the wall which is remote from the liquid film. The wall has an orifice therethrough in its lower zone for the free end of the collecting pipe which extends obliquely upwardly. The collecting opening has a cross section which widens with progressive movement of the collecting pipe through the orifice.