Search: 1850-1859 in date 
Knowles, Francis Charles in correspondent 
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From:
Francis Charles Knowles
To:
Sir John Herschel
Date:
[9 October 1856]
Source of text:
RS:HS 11.65
Summary:

Thinks it may be a good idea to utilize aluminium to coat the speculum of reflecting telescopes. Is shortly to take command of iron works and furnaces and hopes to carry out experiments to produce barytic glass.

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
Francis Charles Knowles
Date:
[16 October 1856]
Source of text:
RS:HS 23.182
Summary:

Thinks that aluminum coating on telescope mirrors may work [see FK's 1856-10-9]; also suggests looking into flouric glass containing aluminum for lenses of low dispersion power.

Contributor:
John Herschel Project
From:
Francis Charles Knowles
To:
Sir John Herschel
Date:
[5 December 1856]
Source of text:
RS:HS 11.66
Summary:

Has received news of a cargo of cryolite from Greenland. Outlines the various possibilities of using it for the manufacture of chemicals and glass. Sends his method of manufacturing aluminium.

Contributor:
John Herschel Project
From:
Sir John Herschel
To:
Francis Charles Knowles
Date:
[6 December 1856]
Source of text:
RS:HS 11.67 & 23.184
Summary:

Would be inclined to try a combination of cryolite and silex to obtain a glass. Comments on his process for decomposing alumina by cyanide of sodium. Sorry to see that FK uses the current forms of chemical notation.

Contributor:
John Herschel Project