192 CARNEGIE INSTITUTION OF WASHINGTON. 



STELLAR DISTRIBUTION. 



The confirmation given to the probable existence of a secondary' 

 plane of distribution of the brighter stars, by the apparent existence of 

 a secondary and very similar plane of distribution of the apices of the 

 real motions of the stars, has led the Director to a more thorough investi- 

 gation of the subject, both through a discussion of the distribution 

 of the stars and an examination of their proper-motions. In most 

 statistical methods there has been a tendency to force the results into 

 a state of synometry with respect to the Galaxy. The present investi- 

 gation endeavors to treat the motions and distribution of the stars 

 by taking cognizance of possible irregularities in these elements in 

 different parts of the sky. It is realized that far more material is 

 needed for an exhaustive treatment of the subject, but a few salient 

 features may be detected even with our limited material. 



According to the method adopted for the treatment of distribution of 

 the stars to the 6^^0, the pole of the secondary distribution was placed 

 at R. A. = 160°, Decl. = - 35°. Including stars to the 6^.^5, the pole 

 was shifted to R. A. = 194°, Decl. = - 24°. For stars to the 6^^5 inclu- 

 sive, the pole of the plane of avoidance is at R. A. = 164°, Decl. = 

 + 73°. The large inclination of the plane of secondary distribution 

 with respect to the Galaxy was unexpected, and it was even less ex- 

 pected to find the plane of avoidance nearly at right angles to the plane 

 of secondary distribution. ^Vhen coupled wdth the phenomenon of a 

 secondary plane for the distribution of the apices of the real motions 

 of the stars it is natural to wonder whether we are not possibly dealing 

 with two systems of stars — one very definite, with the Galaxy as its 

 principal plane, the other less definite and considerably inclined to the 

 Galaxy. 



An interesting feature of the investigation is to find the sun's apex, 

 accurately located in the plane of the secondary distribution. 



Certain peculiarities are manifested in the distribution of the stars 

 in accordance with type. In galactic latitude 0° there is a distinct 

 progression in galactic longitude on the part of the maxima of distribu- 

 tion of the various types from B to K. In latitudes —20° and —40° 

 the points of maximum distribution for type K correspond to mini- 

 mum distribution for type A. 



Further work on this investigation is in progress. 



COLLIMATION OF THE OLCOTT MERIDIAN CIRCLE. 



Mr. Roy has continued his investigation of the apparent lost motion 

 in the collimation of the meridian-circle instrument. In addition to the 

 collimations of the regular observing program he determined 71 under; 

 such conditions as to confirm or refute the probability of a lag. 



The hypothesis of lost motion assumes that the collimation is invari- 

 able as long as the temperature fluctuates within the amount of the 



