Correspondence with the General Post Office and others on Earth currents, disturbances and the maintenance of underground wires, 1891-1911.

Correspondence with C.O. Grimshaw concerning a fault in a dynamo armature, 1893.

Trace showing Earth current curves, sent by E. Raymond Barker, with correspondence, 1898-1899.

Correspondence with C. Chree concerning the details of arrangements for the registration of Earth currents, 1900.

Correspondence with G.E. Preece concerning a magnetic storm, 1892.

Correspondence with Dr Stein requesting details of a photographic system, 1872.

Paper by William Ellis concerning Earth currents, 1879.

Correspondence with W.G. Adams and Professor Förster concerning Earth currents, 1881.

Notes on the determination of scale for Earth current registers, 1886-1889.

Correspondence with South Eastern Railways concerning Earth current wires and abnormal fluctuations, 1891.

Correspondence with G.E. Preece concerning Earth currents recorded on 4 February 1872 and others of 1872-1875.