154 ALEX. L. DU TOIT. 



In strong contrast stands the bore at Normanton 1 in 

 whicli at 2,002 feet a small supply was cut having a tem- 

 perature of 104° F., whereas the maiu flow struck only 

 102 feet lower down possessed a temperature of no less 

 than 151° P.; the granite floor was reached at 2,275 feet. 

 At Mirra Mitta in South Australia, the temperature of the 

 water increased from 122° F. to 176° F. between 3,485 and 

 3,506 feet, and to 190° F. at 3,534 feet. Gregory has 

 quoted also the Kynuna well in which the temperature rose 

 by steps concomitantly with each new flow, the figures 

 increasing from 125° to 150° F. (25°) in the last 242 feet. 

 Symmonds again has drawn attention to the remarkable 

 increase in temperature (107° to 128° F.) — after its com- 

 pletion — in the Neargo bore in New South Wales, accom- 

 panied by a rise in pressure. 



Still more curious is the deep bore at Winton, in which a 

 limited supply with a temperature of 140° F. was cut at 

 3,235 feet, jumping to 182° F. at 3,555 feet; the main flow 

 struck about 300 feet further down is stated to have had a 

 temperature of only 173° F., and this has been maintained. 



It is difficult to conceive, how, under the meteoric 

 hypothesis, such extraordinarily rapid increases as those 

 instanced, could first of all have been produced, and secondly 

 maintained in strata through which the water is considered 

 to be moving laterally with a low velocity, since convection 

 currents, irregularities of flow and conduction, would 

 always tend towards the reduction of such violent thermal 

 gradients. Here we may introduce the question of the 

 stability of a free body of warm water heated from below 

 and compressed from above, but stationary, for, from the 

 known coefficients of expansion, compression and density, 

 it can be calculated that, with a more rapid temperature 

 gradient than 1° F. in 5J feet, equilibrium is rendered 

 impossible. 



x Ann. Eept. Hydraulic Engineer, Queensland for 1896, p. 6 and sec. 9. 



