8 Physical Changes upon the Moon's Surface. [January, 
have occurred appears to be the existence of a strong preju- 
dice against the very possibility of such changes occurring. 
The probable origin of this feeling has been already adverted 
to. This of itself, however, would not have been sufficient, 
of course, to bring about this result ; it remains, therefore, 
to consider the evidence against the reality of any change 
in Linne having occurred that has from time to time been 
brought forward. 
Immediately after Schmidt had announced the supposed 
change in Linne, reference was made to the lunar drawings 
in the “ Selenotopographische Fragmente ” of Schroter, of 
Lilienthal, the earliest of the great selenographers. Amongst 
the very earliest drawings was found one of the Mare Sereni- 
tatis, made on November 5th, 1788, with powers of 95 and 
161, on a refledtor of 6 inches aperture and 7 feet focus. On 
this drawing Schroter does not draw Linne as a crater, but 
not very far from its place he draws a white spot on a ridge 
which he marks v, and a larger dark spot which he marks 
as g. Schmidt considered this white spot v to be Linne, 
and this view has been strongly urged by Huggins, and has 
been generally accepted as correct by astronomers. It has 
been urged, therefore, that as Schroter drew this formation 
in a manner not unlike its present appearance no change 
can have occurred, but that Lohrmann, Beer and Madler, 
and Schmidt must all have been entirely mistaken as to 
what they thought they saw. It was also found that, on 
reference to a map made by Lahire during the seventeenth 
century, no trace of Linne is to be found. It may be, how- 
ever, at once observed that this last fadt is absolutely value- 
less ; the map of Lahire is perfectly untrustworthy in these 
minute details, and Hevelius, Riccioli, and Cassini are little 
superior. From all the maps made about this date 
numerous craters are omitted, far larger than Linne ever 
was supposed to be, so that the fadt of Linne not having 
been drawn proves nothing. These maps were made princi- 
pally by full-moon drawings, where Linne would not be 
visible as a crater. Even, however, had this not been so, 
the value of this negative evidence from Lahire’s map is 
entirely destroyed by the diredt evidence furnished by 
Riccioli’s map, which shows Linne as a distindt crater ; and 
it must be remembered that the present crater on the site of 
Linne could not possibly have been seen by Riccioli with 
the optical means by which the materials for his map were 
obtained. 
The only real evidence, then, that no change has taken 
place in Linne is this single drawing of Schroter’s, which is 
