1S38.] 



in Fort William. 



473 



stratum was not more than five feet in thickness ; five feet of sand then 

 occurred, and after it another layer of clay. At 212 feet a bed of 

 sand was entered, which has been penetrated to a depth of 131 feet, 

 without reaching its termination. 



Long ere this the work would have been carried to the utmost 

 depth for which tubing of the diameter in use has been provided, had 

 it not been for two accidents, each of w hich was of so serious a cha- 

 racter as threatened to put a final stop to the work. The first was 

 occasioned by the separation of a part of the borer containing a valve, 

 when at the bottom of the well ; and the second by the auger be- 

 coming jammed with a brazen plumb which had been lost in the 

 bore sometime before, in such a way that the application of no force 

 that the rods could sustain sufficed to move the implement in any 

 direction. The force that was applied may be conceived when it is 

 stated that it was sufficient to raise the whole line of tubing bodily in 

 the bore. 



Keeping the tubes in position, the rods, by the application of a 

 screw, we re at length forcibly torn from the auger a little below the 

 screw which joined them; after which, as in the former case, the 

 valve worm auger was broken off* by the jumper, and the instrument 

 brought up by the catching in the socket. 



The success in overcoming these disasters must be mainly attributed 

 to the Zealand perseverance of the sappers employed on the work: 

 in the latter, however, they were guided by the able instructions of 

 Captain J. Thomson, who suggested the measures to be adopted, and 

 supplied from his own stores some of the machinery to carry them, 

 into efi'ect.* 



When my superintendence ceased (10th March), the tubes had 

 sunk to the depth of 'S4'^> feet, and the borer penetrated to 336 feet. 

 The sand still continued to rise in the manner described in my former 

 paper. It varies occasionally in colour and substance, and latterly- 

 some pieces of felspar and lumps of indurated clay or sand have been 

 picked out of the sand brought up. 



The supply of English tubing of the requisite character is very 

 nearly exhausted, but an attempt will be made to cast some in Cal- 

 cutta : if it fails, the experiment must necessarily be suspended until 

 an indent that has been sent home be answered. 



* To guard as far as possible against breaking the rods by the force applied to extract 

 them. Captain T. connected his screw with the rod-head, through the intervention of a 

 rod of somewhat smaller section which would consequently give way before any in- 

 jury could happen to the borer.—Eo, 



