Scientists
Letters by H.C. Schumacher (4), Richard Owen and John Pond,1833-1847
Letters on scientific topics including pendulum experiments at Greenwich, Joseph Banks’s wish to purchase a Breguet clock, the anatomy of Brachiopoda, and the weight of a kilogram.

The letters comprise:
Heinrich Christian Schumacher (1780-1850). Four autograph letters signed (‘H.C. Schumacher’) to [the permanent secretary of the French Academy of Sciences, François Arago], Alma, 15 March 1833 – 16 June 1847, in French;
Richard Owen (1804-1892). Autograph draft letter signed (‘Richard Owen’) to [Henri Milne-Edwards], London, 23 March 1845;
John Pond (1767-1836). Autograph letter signed (‘Pond’) to [Jean-Baptiste Biot], n.p., n.d.
Provenance: 1) Sotheby's, 16 May 1978, lot 378; 2) Sotheby's, 11 December 1992, lot 311; 3) Sotheby's, 24 July 1978, lot 246.

Pond discusses a draft of an article sent to him by his correspondent (‘It is quite an original and charming essay, and should only appear in some work of admitted reputation’), his current experiments (‘Ever since your departure I have occupied myself with your pendulum – I find I cannot procure a platinum ball in London for less than 50 Guineas – perhaps you could procure me one more reasonable in Paris – or if you approve of it we could take your smaller ball and Sir Joseph Banks would pay for it through the medium of Sir Charles Blagden.’), ongoing experiments at Greenwich (‘the apparatus erected at Greenwich for the pendulum is extremely beautiful … I begin to fancy myself now tolerably skilful in performing the experiment. […] Everything leads me to think I shall obtain a quantity rather smaller than that deduced from the experiment at Paris’) and the purchase of a Breguet clock (‘In convening with Sir Joseph on the subject of a clock, he seemed to think there would be neither difficulty nor impropriety in ordering a clock of M. Breguet – will you mention this to M. Arago, who I know will be pleased with the commission’). Richard Owen reports on his research on the anatomy of Brachiopoda, an order of molluscs: ‘The fact that the Brachiopoda, likewise, present two distinct auricles, one attached to each ventricle …’ In one letter, Schumacher reports on his correspondence with Friedrich Gauss, who had asked a series of questions about the chargé d'affaires of the King of Hannover, and which Schumacher relays to Arago. In another, he discusses the weight of a kilogram: ‘En même, j’ai découvert que le Kilogramme est actuellement d’environ 1½ milligrammes plus léger qu’il n’était six mois après que M. Olufsen l’eut pesé.’