This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Electroplating without a plating tank is made possible with the following easily homemade apparatus described in a German scientific magazine. It consists of a rubber ball, A, fitted at one end with a glass tube, B, which carries at the opposite end a small sponge. A rod, D, passes through the rubber ball, which is tightly corked at both ends, into the glass tube B and carries at that end the anode E. A small glass tube, F, also connects the rubber ball with the larger tube B. The connections from the battery to the cathode, G, the object to be plated, and to the projecting end of the anode-carrying rod, D, are made as shown. The rubber ball is filled with the electrolyte, and is squeezed so as to force the fluid through the small tube F, into the larger tube, B, filling it and soaking the sponge C. The current is then turned on, and by moving the wet sponge over the cathode G, the latter will be plated. Not only is this an interesting accessory for the amateur's laboratory, but it can be used in the industry where only parts of some object are to be plated, and where it is desired to remedy bad spots without putting the articles back into the bath.
Ill: A Hand Tool for Applying a Plate Electrically to the Surface of Metal