Multi-Electrode Discharge Tube

Ref. A5

This tube’s total length is 30” (75 cm) excluding the caps. The bulb’s diameter is 5.25” (13 cm). It has four electrodes, three of which are flat aluminium discs.

The anti-cathode, at a 45 degree angle, is made of two round metal discs welded together back to back, and covered on both sides by some very thin shiny metallic material, very probably platinum, that has peeled off on some tiny spots.

The end electrodes are cupped in glass. The cap terminals are of the early shallow conical type, with the platinum wire looped around the neck of the cap.

Long open-end vacuum arm, with a very small strongly faded and discoloured label.

In 1908, in a catalogue and price-list of high vacuum laboratory equipment (built according to the specifications of the physicist Dr. Wolfgang Gaede), E. Leybold’s Nachfolger, Cologne, describe this enigmatic item as a “universal experimental laboratory tube, a combination of a cathode ray tube and an X-ray tube”,  and is shown connected to a high-vacuum pump. (List-price: 11.50 Marks).

Source: http://vlp.mpiwg-berlin.mpg.de/library/data/lit59/index_html?pn=11&ws=1.5
(Reference kindly provided by Mr. Alastair Wright)