GOODMAN : APPARATUS FOR BORE HOLES. 
89 
The release device of the clockwork fixes the magnet and 
cone in these positions with respect to the apparatus and to 
each other. 
To facilitate reading the last-mentioned angle, the rim of 
the cone close to the base is marked with degrees all round. 
The angle of inclination of the cone is most conveniently- 
obtained by measuring off by means of a gauge or cathetometer 
the highest and lowest points of the base rim of the cone from 
the base plate. 
In order to apply the apparatus for the purpose of ascertain- 
ing the dip and direction of the dip of the strata, the tube en- 
closing the apparatus is prolonged downwards and provided on 
the inside with one or more cutting or scratching teeth. When 
the lower end of the tube is dropped down over and raised again 
from the unbroken end of the core in the bottom of the bore 
hole, a scratch or scratches are left on the outside of this core, 
so that when the latter is afterwards broken off and raised, its 
position with respect to the apparatus and consequently to the 
readings obtained from the apparatus as previously described 
can be determined, and hence the dip and direction of the dip 
of the strata as shown by the core. 
A modification of the method of using the apparatus for 
this latter purpose is to bore a hole into the core to receive the 
apparatus, and fix it in the core by dropping cement into the 
hole above the apparatus. After the cement has set, the core 
is broken off and raised to the surface with the apparatus inside. 
In order that the apparatus may be more readily and clearly 
understood, a drawing is annexed (Fig. 1), which is a section of 
the inclined part of a bore hole containing the apparatus, the 
latter being shown partly in section : — a indicates the sides of 
the bore hole, and 6 the hollow cylinder enclosing the apparatus ; 
c is the hollow pendulum cone supported by the pivot pin d, 
carried by the base plate e ; i is an agate inserted in the apex 
of the hollow of the cone, to reduce liability to derangement 
from wear between the point of the pivot pin and the part of 
the cone resting immediately on the point. The upper end of 
the cone terminates in a short screwed stem g, and a magnet 
h rests on the shoulder at the bottom of the stem ; A; is a cap 
