gas x-ray tube

Datecirca 1900

Inventory Number2008-1-0060

ClassificationX-ray Tube

Subject

Maker Swett & Lewis Company fl. 1897 - 1910

Maker Macalaster-Wiggin Company fl. 1897 - 1916

Cultural Region

Place of Origin

Dimensions21 x 43 x 15 cm (8 1/4 x 16 15/16 x 5 7/8 in.)

Material

DescriptionAn x-ray tube consisting of a large spherical bulb with several side tubes. Its two longer side tubes, opposite each other, contain disk-shaped electrodes at the end of a thin metal rod. One of them is flat, at the mouth of the large bulb, while the other is smaller, concave, and deeper inside its tube. A small side tube with a vial filled with a white substance (asbestos) connects to the tube with the smaller electrode. A third metal electrode comes from a side tube at a 90 degree angle from the other two and ends in the middle of the bulb in a flat, angled surface.

Signedstamped on glass: SWETT & LEWIS CO / BOSTON, MASS seal stamped on glass: M & W / 7892 / BOSTON

Inscribedsticker with old series number: #A039

FunctionThis is an x-ray tube that functions in a rarefied gas atmosphere controlled by heating an asbestos regenerator (the vial with the white substance in the side tube). It has a thin metal (probably platinum) target at the center of the glass bulb, where electrons coming from the cathode collide, producing the x-rays. The cathode is most likely the smaller, concave electrode in one of the side tubes, with the other electrode probably being a second anode that was thought to improve the performance of the tube.

There is a chance for the larger electrode to also be a cathode, in which case this would be a 2-cathode x-ray tube.

This could be a therapy tube designed for medical purposes. See a similar one here.