1SG9.] ^Ui [Lowric. 



passes from perihelion to aphelion and back. Considering the real form 

 of the moon's orbit in relation to the sun and to the earth and its dis- 

 tances from each, and the vei-y small angles of eight minutes formed at 

 the sun by the radius of its orbit at its quadratures, and of one minute at 

 its syzigies, it does not seem that such inequalities can be mere dis- 

 turbances of the moon's orbit by tlie central force of the sun. 



4. This force would seem also to require a change in the mode of cal- 

 culating cosmical disturbances. Instead of starting us from the basis of 

 an ideal ellipse, depending on a transient force of unknown quantity, it 

 gives us real ones depending on a constant force for each case, Avhich 

 may be calculated. The forms thus given must be the true normal forms 

 of the respective orbits, and departures from them muet alone be treated 

 as disturbances. 



I have only to add that, however unsatisfactory it always is to elimi- 

 nate any element of a system by declaring it anomalous, yet I do not see 

 how this is to be avoided in relation to the satellites of Uranus, if the 

 observations reported about them are accurate. 



Stated Meeting^ October!, 1869. 

 Present, twentj-two members. 

 Prof. Cressox, in the Chair. 



A letter accepting membership was received from Linant 

 Bej, dated Cairo, April 20, 1860. 



An extract from a letter from M. Carlier to Mr. Durand 

 respecting the Michanx Legacy was read. 



An extract of a letter from Mr. Lesquereux to the Secre- 

 tary respecting Mr. Schimper's Palajontologie Vegetale was 

 read. 



Donations for the Library were received from M. Linant 

 de Bellefonds Bey, the British Association, the London Geo- 

 logical Society, Mr. Gore, F. R. S., and the Boston and Mon- 

 treal Natural History Societies. 



The death of Dr. Dorr, member of this Society, at German- 

 town, Sept. 18, aged 73 years, was aunourxcd by Mr. Fraley. 



