908 PROCEEDINGS OF THE ACADEMY OF [DeC, 



rendered them unfit to penetrate strata in whicli pressure tending to 

 crush them would be encountered. The five bore holes were all put 

 down within a very small area. Their object was to find out how far 

 down this hole extends. This object was attained by the fifth alone. 

 Three of the previous holes were stopped by encountering substances 

 which, although not determined with certainty, were in all probability 

 larger fragments of the great meteor. The first was found in bore hole 

 No. 1 under the following circumstances : This hole had been put down 

 about 300 feet, being four inches in diameter, when the piping stuck, 

 and a two and one-half inch pipe was then put down to 420 feet and 

 there stuck. A one and one-fourth inch pipe had been put down 630 

 feet and withdrawn owing to a change in drillers. The hole thus 

 remained idle for some ten days. On resuming work it was found to 

 be filled up to about 380 feet, that is to about forty feet above the 

 end of the two and one-half inch casing. When the drilling was resumed 

 the small pipe very rapidly cleared out the casing and the hole below 

 until it arrived at 480 feet, where it encountered an obstacle that could 

 not be penetrated, although the hole had previously been 150 feet 

 deeper. Against this obstacle the drill was kept rotating two days. 

 It was so hard that it was penetrated less than two inches and would 

 dull the drills almost immediately. It was while rotating upon this 

 obstacle that brown magnetite, resembling that found upon the surface, 

 was gotten from the hole and also the greater number of little iron 

 spheres with magnetite coverings. The obstacle proved impossible 

 to penetrate, and it was attempted to remove it by jetting large quanti- 

 ties of water and also dropping the bit upon it as hard as could be done 

 with so small and weak a line of pipe as one and one-fourth inch, and 

 by this means it was after a long time forced down nearly a foot, thus 

 proving that it was a comparatively small object. As it was impos- 

 sible to get through it or around it, this hole was then abandoned. The 

 one solution of this matter can be that the hole passed very close to a 

 small fragment of meteoric iron or magnetite when it was first put down, 

 and that the subsequent washing of water through the hole had loosened 

 up this object, which subsequently, by the caving of the hole, slid across 

 it and effectually stopped further progress. The next hole. No. 2, was 

 stopped in much the same manner by an obstacle of apparently the 

 same character at 300 feet. This hole was, however, using a four-inch 

 pipe, and on this account and its less depth the object was much more 

 accessible. Much less magnetite and other meteoric material was 

 obtained from this obstacle than from that in No. 1. It wore out the 

 tempered steel drills in the same way. A drill with chisel edge was 



