SKU: A01763 Category:


Description: This fabulous collection consists of nine pages of Herschel’s meticulous barometric readings at the Cape of Good Hope, South Africa and four pages of his presentation notes (all are in his hand, none are signed). Also included is an 1835 letter to Herschel from fellow astronomer Sir Thomas Maclear requesting a verification of certain readings. Ancillary material includes: chemist and collector Prof. Sidney Ross’ Herschel-related correspondence with David S. Evans of The Royal Observatory, a letter from Ross’ buyer, the London antiquarian Peter J. Kroger (the pseudonym of the communist spy Morris Cohen), and miscellaneous Herschel-related papers and articles.

In 1834 John Herschel traveled to the Cape to continue his illustrious father William Herschel’s work and observe stars that were not visible in the English skies. Maclear was appointed as Her Majesty’s astronomer at the Royal Observatory 10 days prior to Herschel’s arrival. Together they observed stars under different conditions from the Royal Observatory as well at the  Feldhausen Observatory, comparing differentials under various climatic conditions, including the equinoxes and solstices. Herschel presented his comparative observations from Oct 1834 to Jan 1836 at a meeting (The S. A. Lit and Phil Institute on Jan 6).

On June 25, 1835, Thomas Maclear, Her Majesty’s Astronomer at the Royal Observatory, Cape of Good Hope, asked John Herschel to take another look at Ceres while studying its placements in relation to other stars. By this time, Ceres was thought to be an asteroid rather than a planet.

“My dear Sir John, Pray if you can conveniently look at Ceres tonight: Last night there was in the field [a diagram of his observation] as inverted. Power 230 on the Lanset [?].  The star Sf1 was 8’ or 9’ distant May 9-10 & the small double star would not bear the slightest illumination.  The R of Ceres observn was 16.57.56 [has symbols above the numerical values] & 1 cm dist 10⁰ .41’. The double star may have been 15’ distant perhaps 10’ would have been nearer the mark. Yours faithfully/ Thom Maclear”

The verso of this letter has Herschel’s manuscript notes recording the hourly difference in barometric readings between Feldhausen, where John Herschel lived, and the Royal Observatory on windy and calm days in June 1835.  [Herschel’s handwriting and style are verified by the Chief Assistant at the Royal Observatory, the astronomer David S. Evans, in a letter dated 4th February 1959 to Prof. Sydney Ross].

In a 1958 letter from Ross to Evans at the Royal Observatory he writes: “The MS of his talk at the meeting of Jan 6th, 1836, gives his method of calculating his difference of levels of floors of F. and O. His conclusion is: ‘Thus it appears that the total difference of the levels in questions is 114 feet 0 inches, with a disagreement inter se of the separate determinations amounting to 3 ft. 4 inches.’ The determinations of which this average is based are those of Dec 1834, June 1835, and Dec 1835. . . .  Another note that might interest you is headed: ‘Height of Table Mountain Cape of Good Hope’ . . .”

Peter F. Kroger writes (March 4, 1958) to Syndey Ross about the purchases he has made at the Auction, the auctions that he dropped out of, and about the “AL’s & MSs” that were too high, while also informing him about the works that would become available at a later date should Ross or the Library be interested.

Herschel’s notes are written on five folio sheets (15” x 9 ½”) and three other smaller pieces of laid paper. Maclear’s autograph letter signed is on a 10” x 8” sheet of laid paper. David S. Evans typed letters  signed (1958 and 1959) are on blue stamped Aerogrammes addressed to Professor Sydney Ross.  Peter J. Kroger’s three page letter is on his letterhead “Rare – Fine Books, Especially Americana, 190 Strand, London, W.C.2, England.”

Sir John F. W. Herschel 1st Baronet (1792-1871, the son of Sir William Herschel (who discovered Uranus), was a mathematician, inventor, astronomer and an accomplished chemist. He is as important as William Henry Fox Talbot and Louis-Jacque-Mande Daguerre in photographic circles for his discovery of “hypo” (hyposulphite) as a fixing agent in photography. He also coined the terms, snapshot, positive and negative and possibly “photography” as well. He was a life-long mentor to the photographer Juia Margaret Cameron. As an astronomer, he studied binary stars to arrive at an understanding of gravitational forces, invented a way to measure solar radiation, recorded the locations of as many as 68, 948 stars, observed Halley’s comet, and the satellites of Saturn. He wrote Outlines of Astronomy (1849), a book for educated lay people. He worked with Thomas Maclear at the Royal Observatory in South Africa between 1833-1837.

Sir Thomas Maclear (1794-1879) was an Irish-born astronomer appointed as Her Majesty’s astronomer at the Royal Observatory, in the Cape of Good Hope. He performed a survey of the Southern sky with John Herschel (1834-1837), performed a geodetic survey (1841-48) of the Earth via an arc measurement, etc. His observations–of the double stars, the nebulae, Halley’s comet– were routinely published in Memoirs or Monthly Notices of the Royal Society. He was also an intimate friend of David Livingstone.

Sydney Ross (1915-2013), a leading chemist and “bibliophile extraordinaire”, was a professor of colloid science at RPI, Troy, NY. He was deeply interested in the history of science and has numerous publications on Faraday and Herschel. He purchased many works through Peter J. Kroger, an antiquarian in London.

David S. Evans (1915-2004), a scientist and astronomer, was a Chief Assistant at the Royal Observatory in Cape Town before he accepted the position of Professor of Astronomy and Associate Director of the McDonald Observatory at the University of Texas, Austin in 1968.

Peter J. Kroger was the pseudonym of Morris Cohen (1913-1992), an avowed American communist and spy. He and his wife Lona moved to England in 1954 to avoid detection. Posing as a New Zealander, Peter Kroger opened an antiquarian book business in the Strand, London. He and his wife were among the five of the Portland Spy Ring–an active espionage group in the UK between 1953-61.

Item #A01763

Condition: Save for a few ink smudges and tiny edge tears, the notations are in very good condition with the writing legible and clear.