February 2jrd, /pop.] PK0CEEJ:)IN(;s. xvii 



Mr. 'rhor[) stated that when required as a "silvered" 

 grating, it was necessary that the surface should be very perfect, 

 any inequality in such a reflecting surface being — ^^ or 4//, 



where the refractive index is 1-5, more prejudicial than in a 

 transmission grating. 



Mr. Thom.as Kay exhibited a fossil coral, stated on the 

 authority of Dr. Hoyle, of the Manchester Museum, to be a 

 s{)ecimen of the Syri7igopora ramulosa, a carboniferous fossil, 

 and some spherical concretions of clay, which were found in the 

 sandhill of Hempshaw Lane, in Stockport. 



Its place in these sand hillocks, which were formerly dunes 

 by prehistoric lakes and rivers associated with the geological 

 fault which stretches from Bredbury to beyond Poynton, may be 

 due to its having been carried down from the great Derbyshire 

 carboniferous plateau by one of its earliest streams. The speci- 

 men has been silicified, whether by deposition of silica on the 

 carbonate of lime, or by the replacement of the latter by the 

 silica, was not certain. 



Professor F. E. Weiss read a paper entitled '"A Preliminary 

 Account of the Submerged Vegetation of Lake Winder- 

 mere as affecting the Feeding Grounds of the Fish." 



Mr. F. Stubbs read a paper, communicated by Mr. T. A. 

 Coward, F.Z S., entitled "The Use of Wind by Migrating 

 Birds.' 



The two papers are printed in tiie Memoirs. 



Special Meeting, March 9th, 1909. 



The President, Profe.ssor H. P. Dixon, M.A , F.R.S., 

 in the Chair. 



The Wilde Lecture, on " The Influence of Moisture on 

 Chemical Change," was delivered by H. BRp:REiON Bakkr, 

 Es([., I ).Sc., F.R.S., Lee's Reader in Chemistry in the University 

 of Oxford. 



