2] 8 Fresh Notes on the Crater Linne. 



there can be no doubt, it having been recorded by several ob- 

 servers. I also mention (Intellectual Observer, vol. x., p. 445) 

 a somewhat similar object on the Mare Crisiuni, west of Picard. 

 The evanescent or permanent character of these and similar 

 objects it wonld be well to determine. In his last communica- 

 tion to me, Dr. Schmidt mentions a faint, light tail, of about 

 4' 6 English miles in length, perhaps analogous to the streakV 

 from Messier. This he did not remark until Jan. 24, 1867. 

 It may have originated from a further overflow of the matter 

 filling the crater. This also is an object deserving of attention. 

 "The similarity of the reflective power of Linne under a 

 high illumination, both before and after the change that has 

 taken place,, is curious. It appears to indicate that whatever 

 may be the nature of the injected material, its reflective power 

 is much the same as that of the interior surface of the former 

 crater during the last 20 years ; and, comparing it with the 

 records which we have of the former brightness of Linne, the 

 reflective power has declined of late years. (Intellectual Ob- 

 server, vol. x., p. 446.) 



" Connected with this subject, we find — very extensively 

 indeed — scattered over the moon's surface, especially at the 

 time of full, both small and large bright spots, some of which, 

 when near the terminator, are seen as craters ; while others, 

 even under the greatest amplification, exhibit nothing whatever 

 of the crater-form. The Rev. W. R. Dawes notices spots of 

 this nature in his interesting description of the small craters 

 which he observed on Plato in January and April, 1863 [Monthly 

 Notices of the Royal Astronomical Society, vol. xxiii., p. 222). It 

 would be well for observers carefully to watch from time to 

 time these bright spots, especially as we have now a veritable 

 instance of the formation of one, which possibly may undergo 

 further change, and it is not unlikely that changes may be 

 detected in some others. As a large number of these bright 

 spots are found on the Maria, monographs of the craterology of 

 each .Mare, . such as I have attempted for the Mare Crisium, 

 would be very valuable. See Report of the British Association for 

 the Advancement of Science, 1865, p. 292." 



Products op Volcanic Action. 



With a view to facilitate a comparison between lunar and 

 terrestrial volcanic action, the following facts and considerations 

 may be useful. 



Volcanic action on the earth results from a highly heated 

 condition of large masses of matter below the surface of the 

 globe; but it is not necessarily, or even probably, directly 

 connected with a great internal molten sea, such as many geo- 



