Siemens spark transmitter, consisting of spark gap, inductance coil and key, mounted on wooden base. Made by Siemens Brothers, about 1910.

Physical Description

Two devices, one larger and one smaller, are each mounted on separate polished wooden bases, which are mounted on a single polished wooden base. A third device is mounted directly onto the main base. The larger device (induction coil) contains a large black coil with a vertical brass pillar at each end. One pillar (to the centre of the whole instrument )has a perpendicular brass rod in it with a pointed end facing towards the other pillar, whic does not have a pointed horizontal rod. Two terminals at the end of the coil lead into the main base, while on the other end of the coil, two leads connect to the medium sized device. The medium size device consists of an interupter and a reversing switch. The interupter consists of a pair of coils and a spring mounted armature with one pairs of contacts and an adjusting screw for a rest position of the armature. A plastic bag, attached to the object, contains a screw.

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