1 2 



kk 



339 



found in the lower tertiary formation of Europe, namely, in 

 the Island of Malta, in Southern France, and in Germany on 

 the Danube. In Malta, the teeth only were found, as long ago 

 as 1670. In Southern France, and Austria on the Danube, 

 parts of the skull were discovered. 



Dr. Patterson announced to the Society the confirmation, 

 by the late arrivals from Europe, of Mr. Walker's discovery 

 of the identity of the Lalande star and Neptune, and read to 

 the Society the following letter on this subject from Mr. 

 Walker. 



Washington, D. C, June 1st, 1847. 



My dear Sir, — I send you my Elements VII. of Neptune, derived 

 from Elements V., by clearing them of the efiect of the present dis- 

 turbing action of the three great planets (that of the others is almost 

 insensible). 



The pure elliptic formula — 



(I.) .... 

 becomes, in the disturbed orbit, 



1 2 r' r' n' n' 



(^•) • • • • ^ = 7 k'k' 



In which the accented quantities are the disturbed values of the el- 

 liptic quantities above: k is the Gaussian constant, and Je' is a simi- 

 lar quantity for the actual position of all the masses of the system, 

 December 7th, 1847. No. (2) gives, from the values furnished by 

 least squares,— 



k' = 3545.489 , k = 3548".188 

 a' = 30.17775 



ft' == k' a' ~~ ^ = 21".41144 

 T' = 165y.7175 



These values of a', ft', and T', substituted for a, /«., and T, in Ele- 

 ments V., give Elements VII., which are a first approximation to- 

 wards the pure elliptic elements of Neptune. The following com- 

 parison of Lalande's observations, as reduced by Mauvais, Comptes 

 Rendus, 1847, No. 16, will serve as a test of the ephemeris from 

 these Elements. The places are referred to the mean equinox of 

 Jan. 1st, 1847, corrected for parallax, but not for aberration. 



VOL. IV. 2 Y 



