The Darwin family are anxious for FEEW’s and Hensleigh’s opinions of CD’s journal. EW is convinced that Henry Holland is wrong if he thinks it not worth publishing.
The Darwin family are anxious for FEEW’s and Hensleigh’s opinions of CD’s journal. EW is convinced that Henry Holland is wrong if he thinks it not worth publishing.
Definition at the Observatory last night was abominable; therefore no comparisons can be made between the stations. Much obliged for the details of the actinometer. Will call on JH later.
Introduces [Charles?] Cameron. Received angry and excited letter from Charles Babbage. Discusses barometers. Heard Herschels may be travelling to Rio de Janeiro.
Setting a unit of measurement for solar radiation (the 'actine'); proposes to 'take for a unit of solar heat that which if all employed in heating a cubic inch of water exposing a horizontal surface of one square inch, to a vertical Sun during one minute would produce a dilation of one thousandth part of its volume.'