87 
ON AN APPARATUS FOR DETERMENING THE INCLINATION AND 
DIRECTION OF BORE HOLES AND THE DIP AND DIRECTION 
OF THE DIP OF STRATA PASSED THROUGH BY BORE HOLES. 
BY JOHN GOODMAN, PROFESSOR OF ENGINEERING 
IN THE UNIVERSITY OF LEEDS. 
{Read Uh March, 1909. Manuscript received 30th December, 1909.) 
The apparatus is for the purpose of determining the inclina- 
tion and the direction of the inclination of bore holes, which 
when carried to a great depth are liable to run away from the 
vertical direction. It furnishes also means whereby the dip or 
inclination of the strata passed through by the bore holes and 
the direction of the same can be ascertained. 
The apparatus consists of a hollow pendulum, in the form 
of a hollow cone of any light and suitable material, preferably 
non-magnetic. Aluminium is well suited for the purpose. The 
full angle of the pendulum cone is about 100 degrees. 
A pivot pin secured to a circular base plate supports the 
pendulum from the apex end of the hoUow of the pendulum 
in such manner that the base plate and pivot pin can be tilted 
at a considerable angle and still allow the pendulum to hang 
truly vertical. An agate bearing is inserted in the apex of the 
hollow of the pendulum or cone. A magnet is secured to the 
upper end or apex of the pendulum by a screw projecting from 
the apex of the same and passing through a hole in the centre 
of the magnet, and a nut or cap screwing on to the same. The 
nut is formed with a hemispherical cap, the centre of which, 
when the nut is screwed down on to the magnet, coincides with 
the point oi support for the cone, that is the point of the pivot. 
The above-mentioned base plate is connected by two or 
more pillars to a second circular base plate — the clockwork base 
plate. 
A spindle is provided passing through a central hole in the 
clockwork base plate in the same vertical line as the pivot, and 
carries a plunger or enlargement at its lower end, the underside 
of which is hollow, so that when pressed against the upper side 
F2 
