From:
Sir John Herschel
To:
William Henry Fox Talbot
Date:
[3 March 1839]
Source of text:
TxU:H/L-0475; Reel 1055
Summary:
Sent WT's specimens to J. B. Biot and F. J. D. Arago in Paris. Developed paper sensitive to heat rays of sun 'beyond the spectrum.' Diagram of three spectra: 'luminous, chemical, and thermic.'
Contributor:
John Herschel Project