210 



J. L. C. RAE, 



F. PITTMAN, AND T. W. E. DAVID. 



layer of paraffin wax around their bulbs prevented any appreciable 

 alteration in the height of the mercury column taking place before 

 the records were taken. 



The following diagram shows, to scale, the arrangement of 

 thermometers in the holes : — 



— Rock Temperatures 

 •Sydney Harbour Colliery 



Sketch showing arrangement of Thermometers in holes 



On one occasion (at the 951 feet level) the thermometers were 

 left in the holes for almost nine days, and on another occasion (at 

 the 606 feet level) for eighteen days. This was during the time 

 occupied in putting in a section of brick walling in the shaft, 

 immediately above the level where the thermometers were placed, 

 it being impracticable to remove the thermometers whilst this 

 work was going on. The whole of this part of the work was done 

 by one of us (Mr. Rae the manager of the Sydney Harbour 

 Colliery) assisted by the contractor for the sinking of the shaft 

 (Mr. T. Cater). 



III. Section of strata passed through in sinking the Birthday 

 Shaft, Sydney Harbour Colliery, Balmain. — The following section 

 was taken by Mr. W. S. Dun, Palaeontologist to the Geological 

 Survey of N. S. Wales, and one of us (Mr. Rae): — 



