19 [108] 



fixation. From this report it appears that the specimens are of much 

 scientific interest, showing as they do, for the first time, the existence in 

 this country of an eocene deposite, rivaling in the number of its species of 

 extinct animals the celebrated basin of Paris. 



Occultations. — It has be,en mentioned in the preceding reports, that lists 

 of occultations, and tables of reductions, have been published, from 1848 to 

 1851, inclusive. The cost of the computation of these tables, as well as 

 that of their publication for the past two years, was borne by the Institu- 

 tion, but since then Congress has ordered the establishment of an American 

 Nautical Almanac; and as these tables will form a part of this ephemeris, 

 Mr. Preston, the late Secretary of the Navy, directed that the expense of 

 the computation should be defrayed from the appropriation for the Almanac, 

 the printing and distribution to be at the charge of the Institution. A 

 similar order has been given by the Hon. Win. A. Graham, the present 

 Secretary of the Navy, relative to the tables for 1851 and 1852. 



The tables for 1852, are much extended' by the introduction of occulta- 

 tions visible in every part of the earth. The form is also somewhat altered 

 in order better to adapt it to the arrangement to be adopted by the Nautical 

 Almanac. 



The primary object of these tables is to facilitate the accurate determi- 

 nation of the longitude of places within the territory of the United States, 

 and in this respect they have done good service, especially in the hands of 

 the officers of the coast survey, and the explorers and surveyors of our new 

 possessions on the coast of the Pacific. Their extension will render them 

 useful to geographers in every part of the world. They have been com- 

 puted, for the present and the last two years, under the direction of Lieut. 

 Davis, the accomplished superintendent of the American Nautical Almanac. 

 As soon as this work, which will be an honor to the country, is ready to be 

 issued, the publication will be relinquished by the Smithsonian Institution. 



We observe again, in this case, the policy of not expending the funds of 

 the Institution, in doing what other means can accomplish. 



It will recollected that Mr. Sears C. Walker, astronomical assistant of 

 the United States coast survey, prepared for the Smithsonian Transactions 

 a memoir containing a determination of the true orbit of the planet Nep- 

 tune, and that from this orbit, and the mathematical investigations of Pro- 

 fessor Pierce, an ephemeris of Neptune was compiled. The ephemeris was 

 prepared for the years 184S and 1849, under the direction and at the expense 

 of this Institution, but for the years 1850-'51-'52, it was computed under 

 the superintendence of Lieutenant Davis, and at the expense of the appro- 

 priation for the Nautical Almanac, while the cost of printing and of the 

 distribution has been defrayed by the Institution. 



The ephemeris has been generally adopted by the principal astronomers 

 of the world, and Professor Airy, the astronomer royal of Great JBritain, 

 has undertaken the labor, in his last volume of Greenwich Observations, of 

 critically comparing his observations on the planet in the heavens with the 

 predictions of the Smithsonian ephemeris. From these comparisons it is 

 found that the ephemeris gives the position of the planet with a degree of 

 precision not inferior to that with which the places of the planets longest 

 kpown are calculated. The labors, therefore, of Mr. Walker on the elements, 

 and Professor Pierce on the theory of the planet Neptune, have been 

 crowned with complete success. It is proposed hereafter to collect all the 



