Photometer

This instrument is an optical photometer for the measurement of the intensity of light and colour. It is made to the design of William Henry Fox Talbot (1800-70), and was constructed by W. & S. Jones, London, around 1830, for an American collector of optical apparatus, Charles Nicholl Bancker.

The operation of the photometer depends on using a hand-cranked pulley device to spin a painted disc on which two or more colours have been assembled on attached segments. At sufficiently high speed the colours appear to merge, enabling a direct visual comparison to made with a test sample and, in principle, allowing the colour of the test sample to be described in terms of the constituent colours on the spinning disc.

In the 1820s, Talbot, like many others of his contemporaries, was deeply involved in experiments concerning the nature of light and colour. Although he only published a partial description of these experiments much later, the ivory plate inside the door reads: 'HF TALBOT'S Revolving Photometer or MEASURER of the Intensity of LIGHT & COLOUR by W. & S. JONES, 30 Holborn LONDON.'

Record details

To search on related items, click any linked text below.