Astronomy. — ''On the ParaUa.v of some Stellar Clusters" (Second 

 comniuiiication). By Dr. W. J. A. Schoutkn. (Coinmunicated 

 bj Prof. J. C. Kapteyn). 



(Gommunicaled in the meeting of February 23, 1918). 



In a former eoiiimmiicatioii it was shown, how it is possible to 

 determine the parallaxes of stellar clnslers from the numbers of stars 

 of determined magnitude in the clusters by means of the luminosity 

 curve of Kaptkyn. The calculation was performed for Messier 

 3 and It and x Persei. Now the same method is used in order to 

 determine the parallax of some other clusters. 



I'he Small Magellanic Cloud. 



H. S. Leavitt. J 777 Variables in the Magellanic Clouds. Annals 

 Harvard Observ. Vol. 60, N^ 4. 



A preliminary catalogue containing 992 stars of the .Snmll Cloud 

 and 885 of the Great Magellanic Cloud. The places of 28 stars of 

 catalogues in the neighbourhood of the Small Cloud are also given. 



We counted a number of stars and estimated their diameter on 

 a photographic plate, taken at the Harvaid Observatory. For orien- 

 tation we used the catalogue-stars the position of which Miss Leavitt 

 communicates. In order to reduce the estimates of diameters to 

 magnitudes, we 



l***!/ counted an area of 1000 G' without the Cloud, and determined 

 from the numbers of stars of every magnitude the magnitude corre- 

 sponding to every diameter by means of Publ. Gron. N°. 27, Tabic IV, 



2ndiy ^g estimated the diameters of 142 variable stars, the magni- 

 tudes of which occur in LEAVITT^s catalogue and which are equally 

 distributed over the Cloud, and we have compared these with the 

 mean magnitude, i. e. the average of maximum and minimum, given 

 by Miss Leavitt, 



S^^iy we have estimated the diameters of the catalogue-stai-s mentioned 

 above and compared these with the magnitudes in the C. P. D. and 

 the A. G. C. 



