44 Transactions of the South African Philosophical Society. 



For the determination of the orbital movement of variable stars, 

 the finest instruments, the most refined mechanism are required. 

 For the determination of the light variation a good pair of eyes is all 

 that is needed. 



I have added this last sentence with the hope that some one in 

 the Society may feel inclined to undertake work that now needs the 

 full energies of half a dozen men to do it justice. 



Six years ago the number of southern variables stood at : 



Algol variables 



Short period variables 4 



Long period variables 10 



These formed pleasant occupation for one man, and time enough 

 and to spare to seek for more. 

 The numbers now are : 



Algol variables 4 



Short period variables 20 



Long period variables 55 



And when the results of that remarkable work the " Cape Durch- 

 musterung " are published, these numbers will be largely increased. 

 There is thus need for more workers, and it is to be hoped that 

 this appeal which I make on behalf of one of the most interesting 

 sections of astronomical work will not go unanswered. 



Addendum to note on New Variable in Centauries. 



I have just received a communication from Professor Pickering, 

 Harvard, which has an important bearing on a conclusion come to 

 in the paper on the new variable in Centaurus. I there state that 

 I am loath to accept rapid variation as a characteristic of the new class 

 of variables, as S. Antliae varies in a period of 7 h. 47 m. Professor 

 Pickering finds that S. Antliae is of the same type as U Pegasi, 

 and consequently of the same type as L 5861, the new variable 

 star. His observations, which were made with the Harvard photo- 

 meter, are very numerous, and apparently conclusive. 



It is pleasant to find, instead of an anomaly, such complete 

 agreement with what theory would lead one to expect ; but of far 

 more importance than this agreement is the outlook which these 

 recent discoveries present. It needs little prevision to state that 



