Draft letter, from Sir John Herschel to Johann Franz Encke, dated at Slough Draft letter. Thanks for his letter, which had been forwarded to his old address. Is pleased he intends working on double stars, though 70 Ophiuchi may prove difficult. Will send some of his own readings for double stars. Like him, he is astonished at the acrimony of the attack on Thomas Young and the Nautical Almanac. 19 March 1830