My Dear Francis –
I really cannot call to mind where Brewster’s sky investigations are to be found1 – I think in the Transactions of the Royal Society of Edinburgh – On them Wheatstones invention of the Polar Uhr,2 for telling the hour of the day by the polarized light of the sky is founded and Wheatstone could inform you where they are to be found – I know Darker of Paradise Street Lambeth can also tell for I remember having some conversation with him on the subject
sincerely yours | J. Tyndall | 11 July 1852
RDS 27/8
Brewster’s sky investigations are to be found: Brewster published numerous papers on the polarization of light in the atmosphere, including ‘Observations on the Lines of the Solar Spectrum, and on those produced by the Earth’s Atmosphere, and by the action of Nitrous Acid Gas’, Edinb. Roy. Soc. Trans., 12 (1834), pp. 519–30 and, more recently, ‘On the polarisation of the Atmosphere’, Phil. Mag., 31 (1847), pp. 444–54.
Polar Uhr: Wheatstone presented his Polar Uhr or Polar Clock to the BAAS meeting in 1848. See letter 0417, n. 12.
Please cite as “Tyndall0642,” in Ɛpsilon: The John Tyndall Collection accessed on 3 May 2024, https://epsilon.ac.uk/view/tyndall/letters/Tyndall0642