SOME GEO-PHYSICAL OBSERVATIONS AT BURRINJUCK. 449 



The opportunity which this engineering work offers for 

 the investigation of the strength of the earth's crust was 

 first realised by Dr. W. G. Woolnough, who was then a 

 lecturer in Geology at the University of Sydney. He 

 suggested that some suitable instrument be installed at 

 the reservoir in order to ascertain whether any deflection 

 of the earth's crust would take place under the water load; 

 and he undertook to carry out the investigation. The 

 Australasian Association for the Advancement of Science 

 granted financial assistance to further the project. The 

 subsequent appointment of Dr. Woolnough to the Chair of 

 Geology at Perth, rendered it impossible for him to proceed 

 with the work. Some time later, the Rev. Father Pigot, S.J., 

 suggested to Professor David that certain pendulums which 

 he had seen during a visit to Europe would be suitable for 

 the investigation, and it was decided to write to Geheimrat 

 Helmert requesting the loan of these valuable instruments. 

 Helmert with the co-operation of Hecker and Wolf most 

 generously arranged to lend three instruments for this 

 investigation, which was planned to extend over a period 

 of three years. The pendulums were shipped to the care 

 of Professor David free of charge, and were received a few 

 months before the outbreak of war. It is a matter for the 

 most profound regret that the spirit, of universal scientific 

 brotherhood so well exemplified by this most generous loan 

 has since been so conspicuously absent from the counsels 

 of the German Government. 



Two of the pendulums lent were used by Hecker (Pots- 

 dam) aad Schweydar (Heidelberg) in their classical investi- 

 gations on the earth tides. These instruments are of the 

 Rebeur-Ehlert type. The third pendulum was constructed 

 to Hecker's design and is of the Zollner suspension type. 



The care of these valuable instruments brought with it 

 a high degree of responsibility for their safe housing and 



Cc— December 1, 1915. 



