Description | Coefficients for reduction of vertical force observations at Madras [Chennai], India during the year 1843. With horizontal vibration of vertical force , needle B; mean dip of the needle during 1843; and vertical vibration of vertical force magnet 1843.
Signed [p.4]: 'S.O.E. Ludlow Supt. Magl. Obsy. Madras', and dated. |