Royal Astronomical Society. 173 



enough to stand in such cliffs, and yet soft enough to slide down 

 a sloping valley as a plastic substance, if the valley were filled 

 with it for many miles long and hundreds of fefet thick; and 

 still more, if there were streams of water running through all 

 parts of the mass. 



I will only make one other remark. Since the banded struc- 

 ture is, as we have seen, an experimenttim crucis between the 

 flexible and the viscous theory, one of the ways in which the 

 application of mathematics to this subject may be really useful, 

 is in determining the form which such bands would assume in 

 the motion of a viscous mass. The problem may be resolved 

 into two: (1) an imperfect fluid slides down a sloping canal; 

 find the form of the lines of separation on the upper surface; 

 (2) on the same supposition, find the form of the lines of se- 

 paration in the medial vertical plane. 



I, and 1 think many other persons, will be very grateful to 

 any mathematician who will help us to the solution of these 

 problems. 



I am, Mr. Editor, 

 Trinity College, Cambridge, Your faithful Servant, 



Januarys], 1845. W. WhewELL. 



XVIII. Proceedings of Learned Societies. 



ROYAL ASTUONOMICAL SOCIETY. 

 [Continued from vol. xxv. p. 315. J 



November 8, 1844. — G. B. Airy, Esq., President, in the Chair. 



THE Secretary read the following extract from the Minutes of 

 Council, dated September 20, 1844 :— 

 "The office of President having become vacant since the last 



Meeting of the Council, in consequence of the death of Mr. Baily, 



it was moved by Mr. Sheepshanks, seconded by Mr. De Morgan, and 



Resolved unanimously. 



That Mr. Airy be appointed to fill the office of President of the So- 

 ciety, until the next Annual General Meeting. 



Resolved also. 



That Mr. Christie be appointed Vice-President in the room of Mr. 

 Airy, until the next Annual General Meeting." 

 Among tbe presents received since the last Meeting of the Society 



the following were announced : — 



I. An equatorial telescope, by Smeaton, presented by Mrs. Somer- 



ville, and accompanied by the following note : — 



"September 12, 1844. 



" Sir, — May I request you will have the goodness to present to 



the Royal Astronomical Society, in my name, an equatorial, which 



was made by the late Mr. Smeaton the engineer, and left to me by 



his daughter, Mrs. Dixon, at her death, who had frequently told me 



