LXXII. NOTES ON HYDRAULIC BORING APPARATUS. 



NOTES ON HYDRAULIC BORING APPARATUS. 



By G. H. HALLIGAN, Chief Surveyor Public Works Department N.S. Wales, 



[Bead before the Engineering Section of the Royal Society of N. S. Wales,. 

 October 19, 1898.] 



In nearly all branches of engineering, it is desirable, if not- 

 necessary, where large works have to be carried out, to know 

 what material underlies the surface, and various means have 

 been adopted to obtain the information economically and speedily. 

 The old practice of sinking shafts and thus exposing to view the 

 strata passed through, has, under certain circumstances, much to 

 recommend it. Shallow holes, from 10 to 30 ft. deep, in stiff 

 loamy soil or clay, can be sunk for from one shilling to two- 

 shillings per foot. When timbering is not necessary, and where 

 only a few holes are required, or a small area is to be investigated,, 

 it is doubtful if any boring plant could be got to do the work 

 more effectively or for the same money. But it is seldom the 

 engineer is fortunate enough to strike such ideal spots. If the 

 lower strata should be sandy, or if water be met with, sinking 

 becomes expensive, if not impossible, and the boring plant is 

 called into requisition. When the surface is swampy or wet, or 

 where the strata underlying a creek or river are to be examined 

 a boring apparatus of some sort is necessary, and it is the object 

 of this paper to indicate the methods adopted and the results 

 obtained by the gear of which the author has immediate charge. 

 Nothing new is claimed in the general design of the various 

 apparatus employed, but a brief description of the difficulties 

 encountered, and the means employed to overcome them, a list 

 and short account of the principal tools used in the work, and 

 last, but not least, the cost of the outfit and the cost per foot of 

 the work done, may be interesting. 



The system of deep earth boring by means of a diamond drill- 

 becomes difficult and very expensive, if it does not entirely fail 

 in soft and especially in gravelly strata. A thin bed of this- 



