460 T. W. E. DAVID AND E. F. PITTMAN. 
beyond Lithgow. The westerly dip at Cremorne proves that the 
bore is situated on the eastern half of this coal basin, and as the 
seam is rising in an easterly direction at Cremorne at the rate of 
about one hundred and ten feet per mile, it should outcrop at sea 
level at a point about twenty-four and three-quarter miles from 
the coast eastwards from the bore. The ocean however here is 
about one hundred fathoms deep, so that the submarine outcrop 
of this seam should lie approximately nineteen and a-quarter miles 
easterly from the entrance to Port Jackson. 
It may be safely predicted that in the near future the coal 
seam at Cremorne will be worked far under the ocean, and already 
a company “The Sydney and Port Hacking Coal Company Limd.,” 
name since changed to ‘‘ The Sydney Harbour Collieries, Limited,” 
has acquired the right to mine for coal under an area of about 
8,000 acres of Port Jackson, Middle Harbour, and Manly Cove. 
V. Temperature.—With a view of ascertaining the temperature 
as accurately as was practicable in the short space of time avail- 
able for the experiment, by the advice of Professor Threlfall and 
Mr. H. C. Russell, the Government Astronomer, some maximum- 
register thermometers were hermetically sealed in a strong piece 
of wrought iron water pipe about two feet three inches in length. 
A. cap piece was ‘sweated on” to the lower end of this tube, the 
threads of the screw in the cap piece and pipe being filled with 
molten solder and the cap piece being screwed on, while the solder 
was still molten. By this means a joint was formed capable of 
withstanding the great pressure to which it would be subjected, 
when lowered to the bottom of the bore, the bore being full of 
water from a level of 2,900 feet to within about three hundred 
feet of the surface, and it being necessary therefore to protect the 
bulbs of the thermometers against this water pressure, in order to 
preclude the possibility of their registration being unduly high 
from that cause. The lower end of the pipe was then filled to a 
depth of about two inches with brass turnings. The thermometers 
were next carefully lowered into the tube. Three of these were 
maximum registering overflow thermometers, made by Negretti 
