Signedon base: ADAM HILGER L'td / LONDON, ENGLAND / No F277.301 / 24201
on base: SOLD BY / ARTHUR H. THOMAS, CO. / PHILADELPHIA, U.S.A.
FunctionAccording the the Adam Hilger trade catalogue, this apparatus "serves for every variety of spectrum analysis by emission spectra."
Primary SourcesAdam Hilger, A General Catalogue of the Manufactures of Adam Hilger (London, 1928), F15.