106
The times of vibration exhibited in Table XII. are each derived from 12 ob- servations of the time occupied by the magnet in making 100 vibrations, corrections having been applied for rate of chronometer and arc of vibration.
The observations of horizontal force given in Table XIII., are expressed in C.G.S. units. The vertical and total forces have been computed by aid of the observed dips.
I have, &c.,
The Honourable A. M. THOMSON,
Acting Coloniul Secretary.
&c.,
&c.,
&c.
F. G. FIGG,
Acting Director.