88 REPORTS ON INVESTIGATIONS AND PROJECTS. 



in the University Observatory, Cambridge, England, is planning to combine 

 them with the Cambridge observations. With that purpose in view, he is 

 supplying the lists of comparison stars, and is deducing their accurate 

 positions. 



Newcomb, Simon, Washington, District of Columbia. Grant No. 233. 

 Investigation of the mean motion of the moon from observations from the 

 earliest historic times to the present, $2 , 500. Grant No. 321, To aid inves- 

 tigations ill matheynatical astronomy , statistical methods , and economic scietice , 

 $5,000. (For previous reports see Year Book No. 2, p, xxi ; Year Book 

 No. 3, p. 90, and Year Book No. 4, pp. 83-84). $7, 500. 



Professor Newcomb submits the following list of researches which he has 

 carried on with the aid of the above grants : 



DiscussioJi of the Mean Motion and other Elements of the Moon from Eclipses 

 and Occiiltatio7is from the Earliest Babylonian Records to the Present Time. — So 

 far as can be determined at the moment, the computations for this work, 

 bringing it up to the end of 1904, are completed. The last stage, that of 

 the final discussion, will be entered upon as soon as practicable. 



Investigatio7i of the Actioyi of the Planets o?i the Moon. — This work was under- 

 taken as a necessary adjunct of the preceding one, because definite conclu- 

 sions from observations can not be drawn until the question of the action of 

 the planets on the moon is settled. As the work was pursued, its ramifica- 

 tions became vastly more intricate than was anticipated, and the method of 

 pursuing it had to be frequently amended and improved. The number of 

 inequalities in the longitude which it is desirable to take account of was 

 found to be nearly 200. It was only in September that the work could be 

 brought into final shape, and it is now in the hands of the printer. 



Discussions of Observatio7is op the Satellite op Ncpttine with a Determination 

 of the Mass of that Planet. — This work was commenced several years ago 

 with the aid of a grant from Miss Bruce. Not being urgent, it is only now 

 approaching completion. Its most important purpose is to determine whether 

 the motions of the planet Uranus indicate the action of any unknown body. 



Investigatio?i of Terrestrial Temperatures to Determine whether they are 

 A^ected by Variations in the Su7i' s Radiation of Energy. — This work, like 

 some others, has proved much more laborious than was anticipated. The 

 heavy computations are, however, believed to be complete, and it only 

 awaits the final discussion of results. This I hope to enter upon at an 

 early date. 



Besides these four works preparations have been made for another con- 

 siderable one, the construction of new tables of Mars. This work will require 

 several years for its completion, and will not be seriously undertaken until 

 the four works above mentioned are finished. 



The Compendium of Spherical Astronomy mentioned in the last report 

 was published by the Messrs. Maemillan in May. 



