ASTRONOMY. 285 



For Alplia Lyrce we have — 



Struve 0". 261 



Main . . 154 



Bruiinow, 1st . 131 



etc., etc. 



Professor Hall's work is especially interesting from the uniformity of 

 the measures and from their great precision, as well as showing the fit- 

 ness of the large telescope for such work. 



At the Dublin Observatory, Professor Ball has nearly completed his 

 investigation of the parallax of Mu Cephei and of Struve 2486. The 

 meridian circle is to be employed in determining the positions of about 

 1,000 stars between— 2° and— 23° for Dr. Schoenfeld. 



Parallaxes of southern stars. — Alpha Centauri, Beta Centauri, JEpsilon 

 Indi and Sirius are being observed at the Cape of Good Hope for par- 

 allax. Two observers, Mr. Gill and Dr. Elkin, are making independent 

 series on the four stars. Dr. Elkin's observations will be completed in 

 September, 1882, and Mr. Gill's in March, 1883. The work is done with 

 Mr. Gill's heliometer. Mr. Gill expresses his admiration for the new 

 heliometer just made by the Eepsolds for the Yale College Observatory, 

 which he regards as the most perfect micrometric apparatus in the 

 world. 



At the Cape of Good Hope much time was spent in 1881 on the de- 

 termination of the longitude Aden-Cape, which is now completed. The 

 Cape catalogue for 1850, containing 4,715 stars, will shortly be published. 



Over 600 occultations, observed since 1834, have been reduced (by 

 means of Newcomb's standard stars) and will be compared with Hansen's 

 tables by Professor Newcomb. 



Under date of May 11, Professor Stone, of Cincinnati, writes: "In ob- 

 serving one of our D. M. zones (—23° Dec.) a remarkable vacuity was 

 found in the region between 16^^ 17™ and 16^ 25™ right ascension. In 

 this region there is no star brighter than 9.5 mag., and only one of that 

 magnitude." 



Stellar Spectra. — From the report of the Astronomer Eoyal for 1882, 

 we extract the following account of his spectroscopic observations of 

 stars: "During the twelve months ending May 20, 1882, the sun's chro- 

 mosphere has been examined with the half-prism spectroscope on 36 

 days, and on every occasion prominences were seen. On one day a de- 

 tailed examination of the whole spectrum of the chromosphere was made 

 at 24 points on the sun's limb. Several prominences have shown great 

 changes in the course of two or three minutes, and large displacements 

 or contortions of the bright lines, indicating very rapid motions of 

 approach or recession, have been noted. In particular, a prominence 

 examined on May 13, 1882, was observed to rise through a space of about 

 30' in less than two minutes, being at the rate of about 110 miles a 

 secoud, whilst the C line showed a disi)lacement towards the red gradu- 



