The design and construction of the instrument now to be described was undertaken on the suggestion of General Walker, of the East Indian Trigonometrical Survey. At the Aberdeen Meeting of the British Association in 1885, General Walker obtained the appointment of a committee to examine into the whole question of the present methods and instruments for the measurement of gravitational force, and to promote investigation, having for its object the production of gravitation measuring instruments of a more reliable and accurate character than those now in use.