ABSTRACT OF PROCEEDINGS. XV1L 



3. " On the Essential Oils of the Angophoras" by H. G. 

 Smith. Remarks were made by Mr. Maiden. 



exhibits : 



1. Model of Bird-shaped Hydro-seroplane, by Mr. A. M. 

 McIntosh. Remarks were made by Mr. L. Hargrave. 



2. Model of Southern Coal Field, made by Mr. L. F. 

 Harper, Geological Surveyor, by Mr. J. E. Oarne with 

 the permission of the Under Secretary for Mines. 



The model represents an area of about 3,600 square miles 

 and embraces the whole of the south-eastern portion of the 

 coal bearing basin of New South Wales, containing all the 

 Southern Collieries. The data necessary for the construc- 

 tion was obtained during a Geological Survey of the area 

 by Mr. L. F. Harper, f.g.s., Geological Surveyor in the 

 State Department of Mines. This work was carried out 

 under the direction of Mr. B. F. Pittman, a.r.s.m., Govern- 

 ment Geologist, and extended intermittently over a period 

 of about twelve years. A number of maps and geological 

 sections have been reproduced and a memoir is now in 

 course of preparation. An outline of the method of con- 

 struction is as follows: — The necessary maps were mounted 

 on a wooden base, the horizontal scale adopted being two 

 miles to an inch. Pins were driven in at all necessary 

 spots, over 2,000 being used, and cut off to scale at the 

 levels represented, the vertical scale being 2,000 feet to an 

 inch, an exaggeration of about 5J times the horizontal 

 scale. Lengths of copper wire were bent to agree with 

 the windings of the principal watercourses, and then 

 mounted in position on stops cut to represent the correct 

 altitude. Plaster of Paris was used to mould the contours 

 roughly and was subsequently carved into the correct form. 

 The area dealt with had been geologically surveyed in 

 detail, so that the data available and personal familiarity 

 with the country resulted in a fairly accurate representa- 



R— Dec. 3. 1913. 



