Royal Institution of Great Britain, 45 1 



sits so closely that he has almost ridden over one in the nest. Mr. 

 Darwin has also been positively informed that several females lay in 

 one nest, and altho\igh the fact at first appears strange, he considers 

 the cause sufficiently obvious, for as the number of eggs varies from 

 20 to 50, and, according to Azara, even 70 or 80, if each hen were 

 obliged to hatch her own before the last was laid, the first probably 

 would have been addled ; but if each laid a few eggs at successive 

 periods in different nests, and several hens, as is stated to be the 

 case, combine together, then the eggs in one collection would be 

 nearly of the same age. Mr. Burchell mentions that in Africa two 

 ostriches are believed to lay in one nest. 



Mr. Darwin then proceeds to notice the other species of Rhea, 

 which he first heard described by the Gauchos, at River Negro, in 

 Northern Patagonia, as a very rare bird, under the name of Avestruz 

 Petise. The eggs were smaller than those of the common Rhea, of 

 more elongated form, and with a tinge of pale blue. This species is 

 tolerably abundant about a degree and a half south of the Rio Negro, 

 and the specimen presented to the Society was shot by Mr. Martens 

 at Port Desire in Patagonia, (in latitude 48). It does not expand 

 its wings when running at full speed, and Mr. Darwin learned from 

 a Patagonian Indian that the nest contains fifteen eggs, which are 

 deposited by more than one female. It is stated in conclusion that 

 the Rhea Americana inhabits the country of La Plata as far as a little 

 south of the Rio Negro, in lat. 41°, and that the Petise takes its place 

 in Southern Patagonia. 



Mr. Chambers then brought before the notice of the Society a 

 simple process for taking impressions from feathers, which is effected 

 by placing the feathers between two sheets of paper, the lower one 

 being previously well damped, and the upper covered with printers* 

 ink; both are then passed through the rolling press of a copper plate 

 printer, and on removing the upper sheet perfect figures of the fea- 

 thers will be left, which may be coloured when dry, and will then 

 have the resemblance of feathers placed on paper. 



FRIDAY EVENING MEETINGS AT THE ROYAL INSTITUTION. 



Jan. 19, 1838. — Mr. Faraday on Electrical Induction. 



Jan. 26. — Mr. Brande on the nature of fatty bodies, and on the 

 application of stearine to the manufacture of candles. 



Feb. 2. — Mr. Goadby on the skeleton of insects. 



Feb. 9. — Mr. Gray on the formation and structure of shells. 



Feb. 16. — Dr. Ainsworth on the progress of the alluviums of 

 Babylonia. 



Feb. 23. — Mr. Faraday on the atmosphere of this and other 

 planets. 



March 2. — Mr. Carpmael on the manufacture of welded iron 

 tubing. 



March 9. — Mr. Griffiths on the philosophy and manufacture of 

 the various means for obtaining instantaneous lights. 



March 16. — Mr. Pereira on the relation between the external 

 form and the optical and other characters of crystals. 



2Q2 



