electric motor for spinning Geissler tubes
Date: 1880-1900
Inventory Number: DW0087
Classification: Motor
Dimensions:54.5 × 17.8 × 21 cm (21 7/16 × 7 × 8 1/4 in.)
DescriptionThe motor sits on top of a round brass pole that is fixed to a circular mahogany base with beveled edges. There are two round posts fixed vertically to the base. Each pole is brass on the bottom and brass on the top (with a small hole on one side), and clear plastic in the middle. One pole is attached to one side of the motor with a coiled, insulated wire. The other pole has a long thin brass arm extending from the brass top to the machine. There are also two brass connectors on the base platform.
An iron circle frame sits on edge on top of the main brass pole. There is an ornamental brass bulb on the top of the frame. There are four, tightly wound coils of wires, insulated in black plastic. The coils are wrapped around orange-colored axes. The axes of two coils line up with the vertical diameter of the iron circle, and the other two axes line up with the horizontal diameter of the circle. Two horizontal iron bands are fixed along the horizontal diameter of the circle frame on both sides by a brass pole at each side of the circle. There is a black handle fixed in the center of the iron band on one side of the motor.
A cylindrical brass pole emerges from the center of the iron band on the other side of the motor. The cylinder acts as the axis for an iron disc fixed part way along it. At the very end of the pole, there is an iron rectangle with a very thin long metal strip emerging from either end. Each strip has a sliding brass cylinder with a screw that, when tightened, holds the slider in place. Emerging from each slider is a short metal pole with two circular prongs branching from it. The outermost prong is a solid circle and the innermost prong is hollow. Together, the four prongs emerging from the two brass sliders constitute a Geissler tube holder. The sliders can be adjusted to fit the length of the tube. Tubes are held in place by the four circular extensions: the hollow circles acting as guides and the solid circles as caps. Each pair of hollow, solid circular extensions is also equipped with a brass topped pin for tightening their hold on tube.