536 THE POPULAR SCIENCE MONTHLY. 



be installed at the same time with a meridian circle of very large 

 dimensions. Under a sky of exceptional transparency these fine in- 

 struments will serve for important researches in the hands of an 

 experienced astronomer, Mr. Marth, the former assistant of Mr. 

 Lassell. 



The question of the constitution of nebulce entered upon a new 

 phase by the appearance of spectrum analysis among the methods ap- 

 plicable to the study of celestial bodies. Since 1869, Messrs. Huggins 

 and Miller have concentrated all their efforts upon this department of 

 research. They have discovered that the unresolvable nebulas are 

 masses of incandescent gas they are suns in process of formation ; 

 while the resolvable nebula? are masses of solid matter, hosts of suns 

 already formed. It has also been established by the aid of the spec- 

 troscope that comets have a light of their own independent of that 

 which comes from the sun, and is reflected by these wandering stars. 

 These discoveries will give to the little observatory of Upper Tulse 

 Hill an honorable mention in the history of astronomy. 



On his side, Mr. Norman Lockyer, at Hampstead, devotes himself 

 to the spectroscopic study of the sun. He sought for a long time 

 to discover a process for observing in a regular manner the rosy pro- 

 tuberances on the solar border, which had thus far been seen only 

 during total eclipses. Hoping that the spectroscope would betray the 

 presence of the red flames on the contour of the star at ordinary times, 

 Mr. Lockyer constructed an apparatus of several prisms, and in Octo- 

 ber, 1868, succeeded in discovering the traces of a protuberance in the 

 spectrum of the solar border. Two months previous, M. Janssen, a 

 French astronomer, who went to India to observe the total eclipse of 

 the 19th of August, was in possession of an analogous method for the 

 study of protuberances, but the announcement of his discovery reached 

 Europe on the very day when Mr. Lockyer announced his own to the 

 scientific world. By enlarging the slit of the spectroscope, the red 

 flames can be seen directly, and the rapid changes followed. Astron- 

 omers now draw them at any time. Two years since, Mr. Lockyer 

 succeeded in producing artificial eclipses of the sun by the interposi- 

 tion of a copper disk, which plays the role of the moon in eclipses, and 

 he thus obtained several drawings of the solar atmosphere with all its 

 minute details. 



Mr. Carrington, at Redhill, has chosen another specialty ; he has 

 devoted eight years to a long series of observations of solar spots, 

 which have led to remarkable conclusions relative to the constitution 

 of the sun : the unequal velocity of rotation of the different regions of 

 the solar globe would prove the existence of immense currents in th3 

 atmosphere of this star. The observatory of Mr. Isaac Fletcher, at 

 Tarn-Bank, Cumberland, was created for the systematic study of dou- 

 ble stars, a study which had also for many years occupied the atten- 

 tion of Admiral Smyth, at the observatory of Hartwell, where he was 



