444 T. W. E. DAVID AND E. F. PITTMAN. 
publication. The present paper, however, is intended to be a 
short summary of the chief results attained by these bores. 
The proving of a magnificent seam of steam coal over ten feet 
in thickness, at the second bore on the shores of Port Jackson, 
should mark an epoch in the history of the development of the 
coal resources of Australia, and shows that the estimates previously 
formed as to the available coal supply of this country have been 
probably under estimated. 
Il. Previous References to the probable occurrence of Coal under 
Sydney.—The late Rev. W. B. Clarke was probably the first who 
argued on scientific evidence, the probable occurrence of coal 
under Sydney. In his evidence before the Select Committee of 
the Legislative Council on coal enquiry held in Sydney in 1847, 
Mr. Clarke said, ‘‘ If we take a dip of only 1° from Newcastle to 
the South and from Illawarra to the North, the synclinal curve 
will meet at the entrance to Broken Bay, which is exactly half- 
way (the extremity probably of the minor axis) at a depth of 
4,680 feet, the depth of the coal seams if continuous.”* 
The late Examiner of Coal-fields, Mr. William Keene, prepared 
a geological section illustrative of the manner in which the coal 
seams in the Newcastle and [llawarra Coal-fields respectively, 
dipped under Sydney. We are not aware whether this section 
was ever published, but it was exhibited to one of the authors by 
Mr. T. Adams, the late Mayor of Raymond Terrace. 
Mr. J. Mackenzie, F.a.s., the present Examiner of Coal-fields, 
as early as 1866, referred to the probable occurrence of coal under 
‘Sydney, in a lecture delivered in Sydney, and in ‘“ Mines and 
Mineral Statistics 1875,” published some sections of the coal 
measures of New South Wales, dividing them in descending order 
into (1) Upper Upper Coal Measures, (2) Lower Upper Coal 
Measures, (3) Upper Marine Series, (4) Lower Coal Measures, 
* Appendix, Report from the Select Committee Legislative Council on 
Coal Enquiry, 1847. Vide also, “ A Sketch of the Physical Structure of 
Australia,” by J. Beete Jukes, m.a., F.a.s., London 1850, pp. 19-22. 
