Unpublished letter, 'On the visibility of certain rays beyond the ordinary red rays of the solar spectrum' from J T Cooper to Michael Faraday

Description

Cooper explains how he has observed an extension of the red portion of the solar spectrum, beyond the space it occupies when seen by the naked eye, by viewing it through a piece of deep blue cobalt glass. He finds that the part of the spectrum thus rendered perceptible to the right is crossed by two or more very broad lines or bands, and he observes that the space occupied by the most powerful calorific rays coincides with the situation of the red rays thus rendered visible by transmission through a blue medium.

Marked on front as 'Archives' by Peter Mark Roget.

Subject: Optics

Received 4 May 1839.

Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 4 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'On the visibility of certain rays beyond the ordinary red rays of the solar spectrum' [attributed to J S Cooper].

Reference number

AP/23/4

Earliest possible date

01 May 1839

Physical description

Ink on paper

Page extent

4 pages

Format

Manuscript