7th June 1856
My dear Tom.
I ordered one or two little things bearing upon your proposed experiments at the breaking up meeting1 – they are now beside me, and consist simply of a Delarue’s pile,2 a steel cylinder magnet along which it moves, a simple contrivance for shewing the attraction, & repulsion of electric currents. Shall I send the things to you by rail or wait until I go myself and take them along with me
affectionately John
RI MS JT/1/T/624
breaking up meeting: the end of term Open Day for Queenwood parents and investors on 16 June 1856. See letters 1226 and 1227. Hirst never used the apparatus since he left Queenwood abruptly on Wednesday 11 June.
DelaRue pile: an improved version of Daniell’s constant voltage battery which Warren de la Rue devised in 1836. ‘On Voltaic Electricity, and the Effects of a Battery Charged with Sulphate of Copper’, Phil. Mag., 9 (1836), pp. 484–7 and 10 (1837), pp. 244–6.
Please cite as “Tyndall1236,” in Ɛpsilon: The John Tyndall Collection accessed on