84 REPORTS ON INVESTIGATIONS AND PROJECTS. 



A Compendium of Spherical Astronomy with applications to the 

 determination and reduction of positions of the fixed stars. This 

 work was completed last June, has been accepted for publication by 

 the Macmillan Company, and is now being printed. 



Observations of the Zodiacal Li^ht from the Brienzer Rothhorn, 

 showing that this light, instead of being merely extended along the 

 zodiac, as heretofore described, can be seen surrounding the sun on 

 all sides. The observations and conclusions were published in the 

 Astrophysical Journal for October, 1905. 



On the Eclipse of Ag at hoclcs (Monthly Notices Royal Astronom- 

 ical Society, vol. lxv, No. 2). This eclipse seems to strengthen the 

 conclusion that the actual retardation of the earth's rotation from 

 century to century is much smaller than was formerly supposed. 



The reduction of occultations of stars by the moon observed since 

 1750, with the correction of the moon's motion from them, is prac- 

 tically completed, so far as the heavy computations are concerned. 

 This work on the motion of the moon is to some extent carried on 

 in cooperation with the Royal Observatory, Greenwich, the latter 

 being engaged in working out the results of the meridian observations 

 of the moon made at that institution. 



Investigation of the action of the planets on the moon. This proved 

 to be a necessary adjunct to the derivation of results from the occul- 

 tations, and was therefore carried on in connection with the other. 

 Professor Newcomb is actively engaged in securing the completion 

 of this work. 



Discussion and comparison of the temperature of the air at various 

 widely separated points on the globe, from 1871 till the present time, 

 with a view of determining whether the amount of heat radiated by 

 the sun is subject to appreciable change from time to time. The 

 working up of the data for this work has been somewhat delayed, 

 but its completion requires little other than routine computations, 

 which are proceeding as fast as circumstances permit. 



Dr. Frank E. Ross, acting as principal assistant in the works on 

 the moon, has completed and published the following : 



Investigation of the orbit of Phoebe, the ninth satellite of Saturn. — 

 This work has been published by the Harvard Observatory in volume 

 Lin, number 6, of its Annals. 



Preliminary orbits of the sixth and seventh satellites of fupiter. — This 

 work has been published by the Lick Observatory in numbers 78 

 and 82 of its circulars. 



