lOO CARNEGIE INSTITUTION 



southern pole is only one-fifth that which pertains to the one-fourth 

 of the sky nearest the northern pole. For the faint stars the dis- 

 parity is much greater. The observations for the determination of 

 the positions of all stars down to the ninth magnitude have been 

 practically completed down to the thirty-second parallel of south 

 declination. It is not known that there is any immediate prospect 

 of a further extension southward of these much-needed observations 

 upon the programme of the German Astronomical Society, and it is 

 difiicult to see how anj- considerable part of the energies of existing 

 southern observatories can be spared for this purpose. It will even 

 be difiicult for them to make the necessary meridian observations to 

 provide proper deductions from the catalogue plates of the astropho- 

 tographic survey. 



(2) The modern revival of interest in double-star measures has 

 extended but feebly to the southern sky. There are no very large 

 telescopes in the southern observatories. By far the largest is the 

 eighteen-inch visual telescope paired with the photographic tele- 

 scope of the McClean Equatorial at the Cape. Even this is not 

 available for very much work upon double stars. 



(3) Much work is being accomplished by several astronomers in 

 the British colonies and at the Arequipa station of the Harvard 

 Observatory upon variable stars. Much work is required, espe- 

 cially in that class of observations requiring telescopes larger than 

 eight inches of aperture. 



(4) There is increasing activity in the measurement of stellar 

 parallaxes at northern observatories. Nothing in this line is now 

 attempted upon the southern stars, and very little has ever been 

 done there, except that under the direction of Gill with the Cape 

 heliometer. 



(5) The first measurements of the motions of southern stars in 

 the line of sight are yet to be made by the Mills Expedition, which 

 is soon to be sent to the southern hemisphere by the Lick Observa- 

 tory ; but even then we shall have two telescopes there pitted 

 against six in the northern hemisphere. It is very important that 

 another large reflector should be placed in the southern hemisphere 

 and emplo3^ed for several years, at least, in the measurement of 

 motions in the line of sight. 



(6) It has recently been pointed out that the proper investiga- 

 tion of the variation of latitude requires that there should be one 

 or more observing stations in the southern hemisphere. This is a 

 very real and immediate need. 



