Discussion of the magnetic and meteorological observations made at the Girard College observatory, Philadelphia, in 1840, 1841, 1842, 1843, 1844, and 1845. Third Section, comprising Parts VII, VIII, and IX. Vertical force. Investigation of the eleven (or72
Bache, A. D. 1864. Discussion of the magnetic and meteorological observations made at the Girard College observatory, Philadelphia, in 1840, 1841, 1842, 1843, 1844, and 1845. Third Section, comprising Parts VII, VIII, and IX. Vertical force. Investigation of the eleven (or.