174 ALEX. L. DU TOIT. 



There are a number of bores from which large volumes 

 of gas have been evolved, e.g., Dagworth, Tara No. 3 and 

 Roma in Queensland, more especially that of the Mineral 

 Oil Company, but in those at Roma, owing to the fact that 

 the water and gas were brought to the surface separately, 

 the effect of the latter upon the flow, and especially the 

 consequence of the failure of the evolution cannot be 

 determined. 



This is unfortunate, because there is no doubt that even 

 moderate volumes of gas are capable of raising large quan- 

 tities of water and of thereby inducing static pressures of 

 considerable magnitude. This is shown by Table A. 2, cal- 

 culated from a more complicated formula derived from the 

 one given before; the higher figures are rather uncertain. 



As it happens, these tabulated values represent only the 

 effect of gas rising freely in the bore, the supply of water 

 at the bottom being assumed unlimited in amount, though 

 under such pressure only as otherwise to stand in the pipe 

 at the surface level of the orifice. If, as generally happens, 

 the water and gas at the bottom are under a pressure 

 greater than that simply due to the height of the column 

 in the bore, this additional pressure will have to be added 

 to that induced, given in the table. 



Hence it can be deduced that discharges of gas at the 

 rate of one or more cubic feet per second, are fully com- 

 petent to account for many of the flows found in the Basin; 

 |t would be interesting, therefore, to have more observa- 

 tions made upon the proportion of gas to water in various 

 bores, as it is a common accompaniment. Any evidence 

 bearing upon the variation in yield of the water in relation 

 to the increase or diminution of gas would be welcome, for 

 upon this point little can be gathered. 



Tara No. 3, Queensland, evolved a considerable amount 

 of inflammable gas, but the water-level ultimately sank 



