From:
William Ritchie
To:
Sir John Herschel
Date:
[3 February 1825]
Source of text:
TxU:H/M-0449; Reel 1093
Summary:
Thanks JH for introducing WR's paper on photometer to R.S.L. council. Sends drawing of instrument and alterations to WR's paper that resulted from improvements in instrument.
Contributor:
John Herschel Project