TALBOT4542

Dear Sir,

I propose to leave this on Friday morning, & if the information I have received is correct, I shall be at Lacock Abbey on that Evening with the help of the Railways from Birmingham to Cheltenham & from Cirencester to Chippenham.¹

The following Exp^t was witnessed by Prof^r Bessel ² whose words I copy from his MSS.

“A black plate either of horn or Agate is placed below a polished surface of Silver at a distance of ¹/₂₀ inch and remaining there for 10 minutes; the latter (the Silver surface) will receive an impression of the Figures [&c?] upon engraved upon the former, which may be rendered visible by exposing the Silver plate to the vapours either of Water or of Mercury &ca.”

I shall bring with me Mosers Paper ³ in German which you will be able to decypher.

I am Dear Sir, Ever Most Faithfully y^rs
D Brewster

Leamington ⁴
18 Upper Parade
July 13^th 1842

Henry Fox Talbot Esq^r