Paper, 'On the Velocity of Crookes’ cathode stream' by Lord Kelvin [William Thomson] Thomson writes: 'In connection with his splendid discovery of the cathode stream (stream from the cathode in exhausted glass vessels subjected to electric force), Crookes found that when the whole of the stream, or a large part of the whole, is so directed as to fall on 2 or 3 sq. cm. of the containing vessel, this part of the glass becomes rapidly heated up to many degrees, as much as 200° or 300° sometimes, above the temperature of the surroundings.' Annotations in pencil and ink. Subject: Physics Received 3 December 1892. Read 8 December 1892. A version of this paper was published in volume 52 of the Proceedings of the Royal Society as 'On the Velocity of Crookes’ cathode stream'. 1892