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Photographic Plate Holder, associated with H.G.J. Moseley?, Manchester/Oxford c.1913

Object is on display.
Inventory Number: 15401
Object Type:
Persons: Henry Gwyn Jeffreys Moseley
Date Created: c. 1913
Place Created: Manchester England United Kingdom Europe
Accession Number: 1935-8
Brief Description: This piece of apparatus is attributed to Henry Moseley and was probably constructed and used by him, first at Manchester in 1913 and then at Oxford from November 1913 to the summer of 1914. He studied chemical samples using X-ray spectroscopy and hence determine their atomic number. The results were published in the ‘Philosophical Magazine’ in 1913 and 1914.

This copper box with lid with one side covered with black paper and with an attached brass scale marked 0-30° was most probably used by Moseley as a photographic plate holder to hold the photographic plates used to record and analyse his experimental results. Moseley may have used the brass scale to measure the angular position and separation of the various X-ray lines recorded on the photographic plate, these lines being unique for each chemical element.

X-rays from the target under bombardment passed through a narrow platinum slit to fall on the face of an old crystal of potassium ferrocyanide. Moseley initially detected the reflected X-rays with an ionisation chamber similar to the detector he used in his experiments conducted with Charles Garlton Darwin at Manchester. However, this recording setup was slow and unreliable and so Moseley switched to photography which required him to rebuild his spectrometer according to a geometry discovered simultaneously by the Braggs and de Broglie. By mid-October 1913, Moseley had completed his X-ray spectroscopy setup in its final form with the photographic plate. Within four days, he had obtained results from for chemical elements titanium (Ti), chromium (Cr), magnesium (Mg), cobalt (Co), nickel (Ni), copper (Cu), and silver (Ag). See Heilbron, J.L. ‘HGJ Moseley: The Life and Letters of English Physicist, 1887-1915’ (1974), 86-88 for full details.

See attached narrative 'Henry 'Harry' Moseley and his experiments' for further details.
Provenance: Donated by the Physics Department, University of Oxford, 1935. See 'Accession Record: Extract from Annual Report for 1935' narrative.’
Collection Group:
Material(s): Cu alloys
Height Width Depth Diameter Unit
145 60 77 mm


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