Oxford
May 22.
1846
Dear Sir
I cannot help thinking that a photograph on paper such as you can execute would fully satisfy the purpose of my enquiry – suppose only in the case of the moon – and I would still anxiously beg of you at least to try it for me – the more especially as I know no one to whom I can apply for a Daguerrotype [sic] – I have no experience myself or I would merely ask you for some of your most sensitive paper & try myself – but it would be so far more satisfactory to have an impression from your hands that I hope you will not refuse me.
I believe Birt <1> was never a very thorough Undulationist – but have not read his recent papers –
As to the circular or more correctly “rotatory” polarization I believe that produced by rock crystal is in every respect similar to that by oil of turpentine but both seem to differ in their nature from that found by Faraday <2> though producing effects generally of the same kind – but I believe no theory of the latter has been attempted.
Wartman’s <3> discovery which I learn from you for the first time is very important –
Ever my dear Sir Most truly yours
B Powell
[envelope:]
W H. Fox Talbot Esqre
Lacock Abbey
Chippenham
Notes:
1. William Radcliffe Birt (1804–1881), astronomer.
2. Prof Michael Faraday (1791–1867), scientist.
3. Elie François Wartmann (1817–1886), made important discoveries in magnetism.