PROBLEM OF THE GREAT AUSTRALIAN ARTESIAN BASIN. 151 



A great deal of knowledge concerning the strata could 

 be obtained by the use (at intervals) of a specially designed 

 cylindricalHbit, so that from time to time fragments of the 

 rocks passed through and of sufficient size for examination 

 could be brought up; this method would be much more 

 economical and rapid than the addition of a calyx attach- 

 ment, and for most purposes nearly as effective. 



IV. Temperature of the Waters. 

 (1.) General, 



When it is considered that the rapid increases of tem- 

 perature with depth within the Great Basin, are unequalled 

 over the globe in any other region of undisturbed sedimen- 

 tary rocks, unaffected by volcanic activity, it is perhaps 

 remarkable, that, except by Jack, so little notice has been 

 taken of this abnormal feature, for such it can be termed 

 without fear of contradiction. 



Even in Australia, outside the artesian basin, the rates 

 are as low as proved by the few determinations that have 

 been made: — Oremorne bore (1° F. in 80), Metropolitan 

 Colliery (1° F. in 78 feet), Sydney Harbour Colliery (1° F. 

 in. 91 feet), Bendigo (1° F. in 80 feet), and Broken Hill 

 (very low, perhaps 1° F. in 100 feet). 



Some rapid gradients — to below 1° F. in 20 feet — have 

 been noted from one corner of the Dakota Artesian Basin 

 in the United States, but, as no satisfactory explanation 

 thereof has been forthcoming, they cannot be cited in 

 argument with conviction; on the contrary, a suspicion is 

 raised that the conditions there may find some parallel in 

 those in Australia. 



In Western Australia the coastal artesian basins possess 

 gradients steeper than the normal it is true, the values 

 ranging generally from about 1° F. in 60 feet to 1° F. in 36 

 feet, but over huge areas in the Great Basin rates of incre- 

 ment of from 1° F. in 30 to 1° F. in 22, and occasionally 

 steeper than 1° F. in 20 have been found. 



