Sends formulae for dealing with the apparent differences, in viewing the comet and compared star, due to the effects of parallax and refraction.
Showing 81–100 of 162 items
The Sir John Herschel Collection
The preparation of the print Calendar of the Correspondence of Sir John Herschel (Michael J. Crowe ed., David R. Dyck and James J. Kevin assoc. eds, Cambridge, England: Cambridge Univ. Press, 1998, viii + 828 pp) which was funded by the National Science Foundation, took ten years. It was accomplished by a team of seventeen professors, visiting scholars, graduate students, advanced undergraduates, and staff working at the University of Notre Dame.
The first online version of Calendar was created in 2009 by Dr Marvin Bolt and Steven Lucy, working at the Webster Institute of the Adler Planetarium, and it is that data that has now been reformatted for incorporation into Ɛpsilon.
Further information about Herschel, his correspondence, and the editorial method is available online here: http://historydb.adlerplanetarium.org/herschel/?p=intro
No texts of Herschel’s letters are currently available through Ɛpsilon.
Sends formulae for dealing with the apparent differences, in viewing the comet and compared star, due to the effects of parallax and refraction.
Discusses their table of comet stars.
Much obliged for F. W. Bessel's zone. Thinks his own extra meridian observations of the comet will be respectable. Feels sure Fearon Fallows could not have approved of the supports of the dome. Has been promised the pleasure of inspecting the expenses of the Observatory. Captain J. E. Alexander and Dr. John Murray will call this morning for a parting cup of tea.
Calms TM about not having his comet observations published yet; those published so far are not of much value.
Wants to reset his barometer by TM's.
Asks for TM's barometer and thermometer readings for 20-28 September.
Compares JH's and TM's barometric readings. Criticizes Pierre Morin's work.
Reports on JH's actinometer observations. Explains why he subscribed to 'Col. [Harry] Smith's piece of plate.'
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.'
Testing whether an actinometer with a glass back is more accurate than one without.
Comments on disagreements in stellar observations and on sun spot activity; and requests observations of a specific star.
Wants to borrow TM's carpenter. Found a faint planetary nebula.
Cannot send the Brisbane list by the end of the week. Will not expect J. K. Gibbs until the cart is finished. Returns solar spots.
Notes discrepancies between TM's and Thomas Brisbane's observations.
Exhausted from his meteorological observations, JH will not keep his appointment for tomorrow with TM.
Asks TM to return JH's book of star magnitudes.
About the observation of sun spots and the second satellite of Saturn.
About a variety of observations that JH has made.
Asks TM whether he plans to work today.
Feeling very ill. Discusses adjustments to TM's transit instrument.