The exact date of Baird's arrival in Hastings is not known. Baird in his autobiography (of 1941) mentions his arrival in Hastings as being in 'the late spring' of 1923. Mrs. M. Baird and S.A. Moseley in their biographies referred to the winter of 1922-23 and 1923 respectively; P. Waddell and T. McArthur, and B. Norman in their books suggest late 1922 and 1922 respectively. While in Hastings, the possibility exists that Baird read an article on 'A development in the problem of television' by N. Langer. In his article, Langer described the rudimentary principles of television and proposed a solution based on the use of oscillating mirror scanners, a selenium cell, a 'light valve' of string galvanometer type and a suitable amplifier. The most important aspect of Langer's paper concerned the results which he had obtained from some experiments 'to ascertain the limit of speed of change which a selenium cell was capable of recording'. These results showed that selenium cells were capable of responding to variations in light at a frequency of 10 kHz; that with an increase of speed the sensitivity of the cell was greatly reduced; and that by the use of valve amplifiers it was possible to compensate largely for the loss in sensitivity at high speeds.

Inspec keywords: history; amplifiers; selenium; galvanometers; video recording; television

Other keywords: amplifier; light valve; string galvanometer type; television; selenium cell; oscillating mirror scanners

Subjects: Video recording