Taken from the website http://vlp.mpiwg-berlin.mpg.de
Attributed to Palmer, C. F. 1934. Palmer Research and Students’ Apparatus for Physiology, Pharmacology, Psychology, Bacteriology, Phonetics, Botany, etc.: Manufactured by C. F. Palmer (London) Ltd., Myographic Works, 63a, Effra Road, Brixton, London, S.W. 2. England. (p. 0086, fig. e151)