Draft letter, from Sir John Herschel to Jacques Babinet, dated at Collingwood Autographed draft letter, signed or initialed by sender. No mention of Emmanuel Liais's L'espace celeste in English journals. Contact London publishers to find translator for it. Alexander Herschel is now professor of natural philosophy at Andersonian Institution in Glasgow. Hopes Jacques Babinet's elegant method of measuring gravity by torsion will not die before being put into practice. 5 March 1867