The transcript of this letter is not available online on Ɛpsilon.
Please cite as “Herschel3937,” in Ɛpsilon: The Sir John Herschel Collection accessed on 2 May 2024, https://epsilon.ac.uk/view/herschel/letters/Herschel3937
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.'
Record created for the Calendar of the Correspondence of Sir John Herschel (CUP: Cambridge), 1998 by Michael J. Crowe ed., David R. Dyck and James J. Kevin assoc. eds
Digital record created by Dr Marvin Bolt and Steven Lucy at the Webster Institute of the Adler Planetarium
Converted to TEI by Michael Hawkins, Epsilon Project, Cambridge University Library
John Herschel Project[View Ɛpsilon collection]