106 Journal of the Mitchell Society \_April 



The address of tlie retiring president, Dr. E. C. Pickering, 

 Director of the Harvard College Observatory, on The Study of 

 the Stars was full of interest to every one. I take space to 

 make the following quotation:^ 



The first catalogue of the stars was made by Hipparchus about B. C. 

 128, and was inserted by Ptolemy in the "Almagest," for fourteen cen- 

 turies the authority in Astronomy for the world. This catalogue which 

 contained more than a thousand stars, gave both their position and bright- 

 ness. The earliest copy that is known of the "Almagest" is in the Biblio- 

 theque National in Paris. It is a beautiful manuscript in unical charac- 

 ters of the ninth century. The other later manuscripts unfortunately 

 differ from it and from each other, so that there is some uncertainty 

 regarding two thirds of the stars, owing to errors of copying. A careful 

 study of these discrepancies has been made by Dr. Peters, of Clinton, 

 and Mr. Knobel, of London. Each spent several years on this work, and 

 all the papers are in the hands of Mr. Knobel. He is now preparing the 

 whole for publication and it is hoped that it will be in the hands of the 

 printer in a few months. 



A manuscript of nearly the same age is in the library of the Vatican 

 and this year a revised edition of it has been published. If we had a 

 correct copy of the original work, it would have a great value at the 

 present time. Half a century ago it would probably have given the best 

 existing values of the proper motions of the stars which it contained, but 

 recent observations enable us to compute their position in the time of 

 Hipparchus, more accurately than he could observe them, assuming that 

 the motion was rectilinear. This work might, however, throw light on 

 a possible curviture of the motions. The observations by Hipparchus of 

 the light of the stars have a value that will be considered later 



There are several kinds of variable stars. Variables of long period under- 

 go changes which repeat themselves somewhat irregularly in a period 

 of several months, and at a maximum are often several thousand times 

 as bright as at minimum 



Variables of short period complete their changes in a few days, or hours. 

 Professor Bailey has found five hundred such objects in the globular 

 clusters. In one of these clusters. Messier 3, out of a thousand stars 

 one seventh are variable, all have a period of about half a day, and their 

 periods are known within a fraction of a second. Their light changes 

 so rapidly that in one case it doubles in seven minutes. It is a strange 

 thought that out of a thousand stars, looking exactly alike, there should 

 be a hundred little chronometers keeping perfect time, and whose rate is 

 known with such accuracy. 



Of the many interesting points brought out in the vice-presi- 

 dential addresses before the sections we can here mention only 

 a few. Professor J. McKeen 'Cattell, of Columbia University, 

 spoke on Science, Education, and Democracy. The following 

 paragraphs are worth attention :^ 



The average salary paid to teachers in the public schools of North 

 Carolina is $199, of Pennsylvania $440, of California $817. The state of 



1 Science N. S. .S9 : 2 and 7. Jan. 2, 1914. 



2 Science N. S. 39 : 161 and 164. Jan. 1914. 



