Accession No

6693.1

Brief Description

Crookes tube, paddlewheel type, 20th Century

Origin

Maker

Class

physics; demonstration

Earliest Date

1879

Latest Date

1950

Inscription Date

Material

glass; mica; metal (aluminum)

Dimensions

Crookes tube 330mm (width) x 115mm (height) x 50mm (depth), with wooden stand height is 185mm and depth is 70mm;

Special Collection

Michael J. Clark Bequest

Provenance

Inscription

Description Notes

Crookes tube, paddlewheel type, 20th century

A long sealed glass tube with metal electrodes at either end and a paddlewheel on a central rack. The electrodes consist of exposed metal hooks at the top of bulbs at either end of the tube, connected to aluminum poles facing each other inside the tube. Between the poles, a paddlewheel with mica paddles and a metal axle sits on a suspended glass track or railway (giving the tube its alternate name, "Railway tube") running the length of the tube. The tube sits on a black wooden rack with two V-shaped cradles.

Condition: good, complete

References

Events

Description
"We have seen from the sharpness of the molecular shadows, that Radiant Matter is arrested by- solid matter placed in its path. If this solid body is easily moved the impact of the molecules will reveal itself in strong mechanical action. Mr
Gimingham has constructed for me an ingenious piece of apparatus which when placed in the electric lantern will render this mechanical action visible to all present. It consists of a highly·exhausted glass tube (fig. 8), having a little glass rail- way running along it from one end to the other. The axle of a small wheel revolves on the rails, the spokes of the wheel carrying wide mica paddles. At each end of the tube, and rather above the center, is an aluminium pole, so that which- ever pole is made negative the stream of Radiant Matter darts from it along the tube, and striking the upper vanes of the little paddle-wheel causes it to turn round and travel along the railway. By reversing the poles I can arrest the wheel and send it the reverse way, and if I gently incline the tube the force of impact is observed to be sufficient even to drive the wheel up-hill." Crookes, "Radiant Matter," 1879
26/09/2018
Created by: Matthew Green on 26/09/2018

FM:47390