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Account of a7i atttmpt to form [No. 34> 



shells intermixed was met with. To this succeeded one foot of 

 the blue clay and sand before described, then 4 feet of the same 

 with gravel and petrified shells. By the evening of the 28th 

 idem the pipes had been driven to a total depth from the sur- 

 face of the ground of 24i feet. The last 2 feet were driven with a 

 hcavj^ pipe driver, weighing about i ton, and let fall from a height of 

 4 or 5 feet. Nothing less than this could overcome tl^e friction on 

 the sides of the pipe, and force it through the subsoil. It should be men- 

 tioned that when the pipe had descended below the layer of blue clay 

 and sand, the ingress of salt-water from beneath became much great- 

 er, and could not be kept under as before by the use of the shell. It 

 was necessary, therefore, to force the pipes down into a less pervious 

 stratum, in order to keep the bore as free as possible of salt-water. 

 In boring through the last 4 feet the triangular jumper was sub- 

 stituted for the auger, and the shell used for clearing the bottom of 

 the bore every now and then, as occasion required. Next came co- 

 ral rock and soft sand-stone, through which the jumper made about 

 6 inches in the hour, so that by the evening of the 29th idem, the 

 total depth of the bore, reckoning from the surface of the ground, 

 was 28 feet 2 inches, or 2 feet 3 inches below the bottom of the pipe, 

 which latter M'as driven to 25 feet 11 inches, on the last mentioned 

 date. The S jumper appeared to answer better than the triangular 

 one. From the 29th April to the 5th May the boring was continued 

 through sand-stone of a harder description, to the depth of about 6 

 feet below the bottom of the pipe, but great difficulty was experien- 

 ced in keeping the bore free of water, which rushed in below the pipe 

 almost as fast as it was drawn out above. It was found impractica- 

 ble to drive the pipe any further, owing to the stratum of sand-stone 

 on which it rested. It was observed that the water drawn up from 

 the bore was less salt than before and there was reason to infer, there- 

 fore, that there was fresh water mixed with the salt, and that if we 

 could but keep the latter out, our labour would not be in vain. To 

 effect this it was proposed, after the jumper had bored another foot or 

 two, to insert a smaller size pipe within the one first driven, and to 

 lower it into the bore formed by the jumper, and then to force down 

 a quantity of stiff clay between the two pipes so as to cut off the 

 communication, and stop the rise of salt-water from below. In bor- 

 ing, however, the additional 2 feet an accident occurred, whereby 

 a piece of the pipe, it was supposed, was broken off and remained 

 at the bottom of the bore. A few small pieces of iron were 



