Fresh Notes on the Grater Linne. 215 



selves compose parts. Theories have been formed from 

 astronomical facts, but such theories have always been 

 deficient in anything like firm foundation, in aught but a kind 

 of plausibility. The one solid answer remains alone in all its 

 grand simplicity — " He spake, and it was done ; He com- 

 manded, and it stood fast." 



FRESH NOTES ON THE CRATER LINNS, AND 

 SUPPOSED LUNAR ERUPTIONS. 



The Astron. Nachr. publishes a letter from Schmidt, in which 

 he says, that " at the time of Lohrmann's and Madler's work, 

 from 1822 — 32, Linne was more than 5000 toises wide, and had 

 a very deep crater, plainly visible as such, and when near the 

 phase, more or less in shadow. It was the third in size of M. 

 Serenitatis 3 craters, and was seen and described by Schroter in 

 1841 — 3, and by me." What seems deficient is, positive evidence 

 of the crater-form appearance of Linne, at a more recent date — 

 say shortly before 16th Oct., 1866, since which, Schmidt states 

 that no crater has been visible. His words in this letter are : 

 c< At least since Oct. 16th, 1866, the crater form of Linne at a 

 time of oblique illumination cannot at all be recognized, [dw- 

 chans nicht warhgenomnen zuerden) . The Athens refractor shows 

 at times in the interior a fine black point (feinen schwarzen 

 ■punld), 300 toises (1918*4 English feet), in diameter." 



Schmidt further observes that in high illuminations Linne 

 is always visible as a light spot, and has been so for more than 

 twenty years; and then comes the following passage, which 

 should be considered in connection with the following letter of 

 Secchi's to the French Academy, and with the fact that several 

 English observers have noticed a more or less distinct black 

 spot. 



" If strong eye pieces of 500 to 1000 times magnification 

 occasionally give indications of a crater-form, it is especially 

 necessary to state whether such crater is deeply shadowed, and 

 has the old diameter. If such were the case, at present, large 

 telescopes would not be necessary, and the questions now 

 raised would not have been propounded." 



Schmidt further states that he has satisfied himself by 

 observations during four lunations that Linne is now "never to 

 be seen as a crater of the normal type." 



At a recent meeting of the Imperial Academy of Vienna, 

 Herr Haidinger read a letter from Schmidt, detailing sundry 



