French astronomer (1853-1948) who was director of the Meudon and Paris Observatories, and who invented the spectroheliograph and carried out intensive studies on the behavior of the atmosphere of the sun. The Deslandres crater on the moon named after him, as is Asteroid 11763 Deslandres. Two untranslated ALSs in French, each signed "H. Deslandres," both written to Cambridge astrophysicist Hugh Newall. The first is eight pages on two sets of adjoining sheets, 8.25 x 10.25, Paris Observatory letterhead, August 2, 1929, mentioning Trinity College, Cambridge, the Meudon Observatory, George Ellery Hale, Mount Wilson, and other topics. The second is four pages on two adjoining sheets, 5.25 x 8.25, Paris Observatory letterhead, December 3, 1929, again mentioning Cambridge and Hale. In very good condition, with heavy dampstaining to the first letter, and splitting to the central horizontal fold of the second letter.
