Of those on the other side, two are for connection of the primary coil and the other two are for a possible connection of the condenser.
All the connections of the different parts of the device with the commutators and the outlet terminals are by means of wide strips of bare copper on the wooden platform.
Each of the two switches consists of a glass filled with mercury covered by a thin layer of alcohol, into which is placed a thin brass rod with a platinum point which is wet by the alcohol and penetrates slightly into the mercury. The glass is attached to a copper coaster to which at the centre is soldered a small platinum electrode which, on penetrating into the glass from the bottom, is in contact with the mercury. Each of the two switches is attached to the wooden platform by means of a brass support which is connected to the commutator and thus to one of the poles of the corresponding generator.
The thin rod with the platinum point of the main switch is attached to the end of the longer arm of a brass lever having arms of different lengths; this, instead of lying free, is attached transversally to a flexible, vertical, copper reed held by a sturdy brass bracket by means of a rack shaft that allows regulation of its height. ...continues