1867.] Astronomy. 383 



brightness of Mars varies with varying phase, and (ii) the greater 

 brightness of the disc near the limb. Zollner ascribes these 

 peculiarities to the slope of elevations on the surface of Mars. Mr. 

 Huggins accepts this view as probable, adding that "it is im- 

 portant to remark in this connection that the darker portions of 

 the disc gradually disappear, and the coloured portions lose their 

 distinctive ruddy tint as they approach the limb." This cir- 

 cumstance appears to prove, however, that a considerable por- 

 tion of the light from the limb has been reflected before 

 reaching the planet's surface. If Zollner's supposed mountain- 

 slopes (whose angle he determines at 76° !) existed, we should find 

 brighter colours as well as brighter light near the limb, unless we 

 supposed all the mountain-tops coloured and their declivities white. 



On every hand we receive confirmation of Dr. Schmidt's dis- 

 covery of the disappearance of the lunar crater Linne. After a 

 careful discussion of the evidence, Schmidt comes to the conclusion 

 that the change which has actually taken place corresponds — only 

 on a greatly magnified scale — to the changes produced by mud- 

 volcanoes on our own earth. He conceives that the whole of the 

 internal part of the crater has been filled up by erupted matter, 

 which has further overflowed, so as to obliterate under gently- 

 sloping declivities the once steep outer walls of this vast crater. 

 The matter within the crater seems to have cooled since Schmidt, 

 Secchi, and other observers have detected a minute depression 

 nearly in the middle of the light spot which now marks the place 

 of the crater. If we remember that the crater was described by 

 Lohrnian, Beer and Madler, and others, as " very large " (nearly six 

 miles across) and " very deep," we must recognize the fact that lunar 

 volcanic activity is far from being extinguished. 



The eclipse of the sun on March 6th, like most partial eclipses, 

 presented no features deserving of special comment. The occur- 

 rence of a severe snow-storm in the upper regions of the air 

 during the progress of the eclipse (accidentally discovered by 

 Mr. Browning while changing the focus of his telescope), is so far 

 noteworthy, as it confirms the opinion expressed by many astro- 

 nomers, that although the total eclipse of August, 1868, occurs at a 

 season when in certain parts of India traversed by the shadow fine 

 weather is ordinarily expected, yet unfavourable changes may take 

 place in the weather during the actual progress of the eclipse, and 

 through causes corresponding temporarily to those which produce 

 the regular breaking up of the fine season. We trust this antici- 

 pation will not be verified, and that astronomers will successfully 

 avail themselves of one of the most favourable opportunities that 

 could ever be afforded of determining the real nature of the red 

 protuberances, and other phenomena visible in a total eclipse. 



We have to note an error in our last Chronicle. The deter- 



