1869.] Astronomy. 417 



situated for observation. Venus and Mars will be evening stars 

 throughout the quarter, but the latter is getting too far ofl' for 

 eifective observation. 



Proceedings of the Astronomical Society. 



Mr. De la Kue had called attention to the great changes which 

 appeared to have taken place in the figure of a great solar promi- 

 nence visible during the total echpse of August, 1868. These 

 changes appeared to suggest that the prominence had undergone 

 an axial rotation during the period occupied by the moon's shadow in 

 travelling from Aden to Guntoor. It now appears, however, that 

 the engraving of the Aden photograph in the ' Engineer,' on the 

 accuracy of which Mr. De la Eue had founded his opinion, was 

 incorrectly designed. Mr. De la Eue has obtained a copy of the 

 original photograph, and he finds that the hypothesis of a marked 

 change having taken place must be abandoned. Instead of the 

 Great Horn being so cuiwed that its point was dii-ected in the oppo- 

 site direction from that in which it was tm*ned when seen at Gun- 

 toor, the aspect of the prominence in the two pictures is almost 

 identical. It requires actual measurement to distinguish any change 

 of position. Mr. De la Kue considers, however, that the evidence 

 is sufiiciently distinct to enable us to conclude that some change 

 had occurred in the direction of the great prominence during the 

 forty minutes which elapsed between the Aden and Guntoor obser- 

 vations ; but it is impossible to say whether this was due to an axial 

 rotation of the prominences. 



In a paper on the late transit of Mercury, by Mr. Abbott, there 

 occur some remarks about the geographical position of Austrahan 

 towns, which are interesting in connection with the approaching 

 transit of Yenus. The longitude of Hobart Town appears to have 

 been weU determined, but not with such accuracy as will be required 

 for the application of Dehsle's method to the determination of the 

 solar parallax. Captain Kay agrees with the Astronomer Koyal in 

 considering that the Australian colonies are unsuited for observing 

 the transit of Yenus until better known. Mr. EUery, on the other 

 hand, thinks differently, and considers that the position of the Mel- 

 bourne Observatory is as well known as that of the Cape of Good 

 Hope Observatory. 



A paper by Mr. Mann on the subject of the same transit contains 

 an elaborate discussion of the observations which were made at the 

 Cape of Good Hope, and cannot fail to be highly valuable to astro- 

 nomers who may in future times undertake the formation of new 

 tables of Mercury. It will be remembered that in England the 

 whole transit of Mercury was not visible. Mr. Mann was able to 

 employ observations made by Sir T. and Mr. G. Maclear from the 



