36 Doubts and Facts concerning Linne. 



may be seen on the neighbouring sea-coast at the present day. 

 At a little lower level than the Cheddar ravine there are gene- 

 rally-acknowledged indications (such as sea-shells*) of the sea 

 having once covered the plain between the Mendip range and 

 Polden Hill. During the great glacial submergence the sea 

 may have washed through the Cheddar ravine, and completed, 

 if not entirely effected, its denudation. 



DOUBTS AND FACTS CONCERNING LINNE. 



The progress of investigation into the evidence of recent 

 changes in the lunar crater Linne has cast considerable 

 doubt upon the opinions so positively expressed by Schmidt, 

 and accepted by most astronomers. In order to place the 

 question as fairly as possible before our readers, we now 

 publish a short paper by Mr. Birt, F.R.A.S., and some extracts 

 from an important communication just made by Mr. Huggins 

 to the Astronomical Society, and published in the " Monthly 

 Notices ;" and also a letter from the astronomer Wolf, recently 

 read before the French Academy. 



THE NEW CKATEK ON LINNE. 

 BY W. E. BIRT, P.R.A.S. 



The question of change on the moon's surface, supposed 

 to have been manifested in the case of the crater Linne, 

 with which our readers are acquainted, remains undecided. 

 Bespighi, on the Continent, as well as several eminent astro- 

 nomers in our own country, having come to the conclusion 

 that no change whatever has taken place in the condition of 

 Linne, and that if any appearances have been presented indi- 

 cating change, such appearances are to be explained either by 

 defective observations, by unfavourable conditions of our own 

 atmosphere, by variations in the angles under which we see 

 lunar objects, or by different incidences of the solar light 

 falling upon them. There can be no doubt that each of these 

 circumstances materially affects the appearances of lunar 

 objects, and it is the more important in the instance which 

 is now exciting considerable attention, to Jcnoiv more fully the 

 facts rather than to rest on the conclusions that may have 

 been drawn from a partial examination of facts presented, it 

 may be, by a single series of observations. 



* At Burtle, in the marshes of the river Brue, there are sand-banks full of 

 marine shells, which are believed to indicate a comparatively recent and partial 

 eubmergence of the land. 



