This unique and relatively rare Immisch’sThermometer was patented in England in 1881/1882 by Moritz Immisch, and appears in period medical supply catalogues.  Provisional specifications were recorded A.D. 1881, 6th July, No. 2953.  Its virtues were durability and cost.  It was used for both axillary and oral measurements and on account of the latter, was supplied with a watch chain.