XXVI. ABSTRACT OF PROCEEDINGS. 



The Chairman, announced that a request for the formation of an 

 Anthropological and Ethnological Section of the Society had been 

 received by the Council, and it was desired that members who 

 were willing to attend the meetings and take an active part in the 

 working of the Section, would send in their names to the Hon. 

 Secretaries at an early date, so that the Council might be in a 

 position to deal with the matter. 



The following letter from Sir George Gabriel Stokes, Bart m.a. 

 d.c.l., ll.d., f.r.s., was read: — 



Lensfield Cottage, Cambridge, 

 15 July, 1899. 

 To the Secretary, Eoyal Society of New South Wales. 



Dear Sir, — I write to thank, through you, the Eoyal Society at Sydney, 

 for their kind congratulations, sent me by telegraph, on the occasion of 

 the celebration of the Jubilee of my professorship. The telegram was 

 duly received just at the time of the celebration. 



Truly I have been rewarded, as I feel quite beyond my deserts, by the 

 kind congratulations 1 have received from so many places, some of them 

 far distant from England. 



Will you kindly convey my thanks to the Eoyal Society ? 



T remain dear Sir, yours very faithfully, 

 G. G. STOKES. 



THE FOLLOWING PAPERS AVERE READ : 



1. "Sailingbirds are dependent on Wave-power," by L. Hargrave. 

 The author points out that sailing birds passed most of their 



time over the face or rising side of waves, and that by so doing 

 they abstracted power from the moving water as the progress of 

 the wave raised the air above it at a velocity proportional to its 

 speed and slope. He used Prof. S. P. Langley's results to show 

 that the uplift of a moderate swell was amply sufficient to support 

 a plane and keep it moving at about thirty-five miles per hour in 

 a calm. 



2. "Some applications and developments of the Prismoidal 



Formula," by G. H. Knibbs, f.r.a.s., Lecturer in Surveying, 

 University of Sydney. 

 Starting with a demonstration that the prismoidal formula was 

 rigorously applicable to solids with parallel plane ends, whose 



