of the Hudson River. 3 



the bore-holes with water and lowering to the ends of the holes 

 a gage which would very accurately record the pressure of 

 the overlying column of water, the progress of the holes 

 could be plotted or checked in addition to the records of the 

 cores. Horizontal variation was not measured. The horizontal 

 component is more difficult to record than is the vertical and 

 it was not considered necessary. As is well kno^gi to those 

 familiar with diamond drilling, the holes are apt to swerve, 



Fig. 2. 



Fig. 2. Cross-section of the Storm King Crossing, plotted from the 

 available data. The vertical scale is five-thirds the horizontal. 



sometimes from encountering joints or surfaces from which 

 the drill may cumulatively glance ; or more seriously because 

 of the tendency to turn upward from the sag of the long drill 

 rods which do not fit tightly in the hole. The first pair of 

 holes penetrated exceptionally firm and solid granite with 

 occasional coarse diorite dikes until the depth gave reason to 

 believe that the holes had crossed. 



A second pair of holes were then started at such an angle 

 that they would pass each other at approximately 900 ft. 

 The drilling proceeded without incident worthy of remark, 

 until the depth attained indicated that these holes also had 



