178 POPULAR SCIENCE MONTHLY 



tory. Madame Ceraski has been especially successful in finding vari- 

 ables of the interesting Algol type. Of sixty-seven variable stars dis- 

 covered by her, no less than ten are of this class. This is remarkable 

 when we take into consideration that of over 3,000 variables now 

 known only thirty-eight are of the Algol type. 



Through her generous gifts in aid of astronomical research, the 

 late Miss Catherine W. Bruce, of New York, made her name widely 

 known in astronomical circles. Dr. Max Wolf, director of the Astro- 

 physical Observatory at Heidelberg, was presented by her with a photo- 

 graphic telescope, which has enabled him not only to find some seventy 

 new asteroids, but also to increase materially the number of known 



The Small Magellanic Cloud in which nearly a Thousand Variable Stars 



have been found. To the right is the globular cluster, 47 Tueanse, 



taken at Arequipa in the bruce telescope. 



variables. Dr. Wolf, recently assisted by Frau G. Wolf, has discovered 

 about 200 new variable stars. 



Nowhere else, however, has so large a collection of celestial photo- 

 graphs been made, covering so long a period of time, as at the Harvard 

 Observatory. In 1903, Professor Pickering instituted, among other 

 pieces of work, an examination of the Magellanic Clouds. This work 

 was assigned to Miss H. S. Leavitt, who has shown rare talent for this 

 line of investigation. The regions selected were very fortunate, also, 

 since, aside from the dense globular clusters, no other region has been 

 found as rich in variables as the Small Cloud, although the Large Cloud 

 •also promises to yield nearly as many. It should be noted that the 

 Magellanic Clouds are by no means merely irregular extensions of the 

 Milky Way. They appear to be as unique in structure as in position. 



