Ix Proceedings of the South Africcin Philosoj^hical Society. 



{i.e., in 8|- minutes), would take 4-36 — say 4^ — years to come from 

 a Centauri. 



To return now to other researches with my small heliometer. 

 Altogether in the first campaign we determined the parallaxes of 

 nine of the most interesting southern stars, and the first results of 

 the kind obtained in the Southern Hemisphere. 



With these results I was able to approach the Lords Commis- 

 sioners of the Admiralty and state that this work had been done 

 with a heliometer, my own property ; that in consequence of its 

 small optical power its applications were limited, that in a new instru- 

 ment not only the optical power but the mechanical efficiency could 

 be much increased and the work rendered more rapid and more 

 accurate. Their Lordships were pleased in 1884 to sanction the 

 construction of a new heliometer of 7 inches aperture. It was ordered 

 from Messrs. Eepsold in the same year, and completed in 1887. 



I may here state that my anticipations were fully realised. It 

 was proved (Annals of the Cape Observatory, vol. vii., part 2) that, 

 one observation with the new heliometer was of the same weight as 

 three observations with the old one, and that a set of observations 

 with the new instrument, in consequence of improvements in the 

 mechanical design of the new instrument, could be made in half 

 the time that a similar set could be made with the old one. The 

 efficiency of the new instrument was therefore six times that of the^ 

 old one. 



With the new heliometer a fresh series of investigations for stellar 

 parallax was undertaken. In several instances, by w^ay of test, the 

 parallax of the same star was investigated, and in every case the 

 results with the new instrument agree substantially with those 

 derived with the older one. 



The following table gives the whole of the results arrived at, and 

 contains all that astronomy up to the present time can tell of the 

 distances of the fixed stars- in the Southern Hemisphere. 



