A glass sphere, about 8.5cm in diameter, with four short glass projections, each holding an electrode. A glass bulb is mounted with curved glass stem from the bottom electrode projection to the wooden base. Slight burn marks directly across from the cathode.
Accession Number: 2009.ph.205
Crookes Cathode Ray Tubes; High Vacuum Tube of High/Low Pair
Primary Materials: Wood, Metal, Glass
Markings: Old inventory number = phy63.
Height = 23 cm, Length = 11 cm, Width = 8 cm
Slight burn marks directly across from the cathode.
Associated Instruments: Crookes Tubes (Various)
Likely built by Richard Uri-Muller (Braunschweig).
Date of Manufacture:
Provenance: Collection of Dr. Martin Lee.
Additional Information and References:
Typically sold in pairs, one with a higher vacuum (lower pressure) than the other. The low vacuum tube would result in rays moving up and away from the cathode, towards an active anode, while the high-vacuum companion would show rays moving straight, directly across the cathode. Judging by the marks on the glass, this tube was the high vacuum (low pressure) tube.