44, REPORT—1868. 
The change to and from the white spot in each case is well marked; and it 
now remains to ascertain if this change always takes place with the same 
solar altitudes aud azimuths. To observe the topographical features and 
witness the transition, it is necessary that Linné should be very near the 
terminator. 
Herr von Midlor has obligingly communicated the following memorandum 
respecting Linné :— 
«The insrument I made use of to produce drawings of the moon was a 
refractor of 33 feet of focal length and 43 lines of aperture. Commonly I 
employed a magnifying-power of 300, but the trigonometrical measurements 
have been executed with a magnifying-power of 120, which allowed me to 
reach to the edge of the moon.” 
“Respecting the crater Linné, it was a principal point in my trigonometri- 
cal network, and consequently I have observed it very often. 
«‘T remember that this crater did occupy the greatest part of the diameter 
of the circular wall, so that if a 6 extended over 1-4 Ger- 
eorn as, 
man mile (6:4 English), a’ b' was at least 0-9. AR 
«‘ T have never seen any real change, only optical ones. alter fe 
«‘ Only in or near the full moon it was a white spot, almost i il 
as white in the middle as on the edges; these edges were = SS...’ 
not wholly distinct, but always circular and fit for measure- r= 
ment. 
«The deepness of the crater must have been considerable; for I have 
found an interior shadow when the sun had attained an altitude of 30°. I 
have never seen a central mountain in the interior. 
(Signed) “«« MiprEr.” 
Without expressing the slightest opinion on the questions of change or 
fixity derived from a comparison of the above with recent observations, it 
may be permissible to notice the points of contrast between the earlier and 
more recent observations of Zinné which the statements of the Baron Madler 
afford. Such a comparison and contrast is essential if we desire to arrive at 
a true conclusion. The following appear to be the most important. 
Points of contrast between earlier delineations and recent observations of 
the lunar crater Linné :— 
1st. The earliest authentic delineations and records of Zinné represent this 
object as a crater, assign to it a diameter of about six English miles, and 
speak of it as being very deep. 
2nd. Recent observations, 7. e. from 1866, Oct. 16, to 1868, Sept. 7, are 
decisive as to the existence of a small cone, with crater-opening on the por- 
tion of the Mare Serenitatis surrounded by ridges. 
3rd. It has been assumed that the white spot v in Schréter’s Tafel ix. 
represents Linné as seen on Noy. 5, 1788, and that its present state is 
nearly similar. 
4th. Capt. Noble pointed out,*at a Meeting of the Royal Astronomical So- 
ciety, that a line drawn from Plinius through Bessel will fall on Linné. This 
line on Schréter’s drawing falls very nearly on the dark spot, which is 
very unlike the appearance of Linné at present. 
5th. Herr von Midler has very recently recorded that in 1831 the crater- 
opening occupied 0-9 of the diameter of the external wall, which measured 
about 6:4 miles English. 
6th. The diameter of the base of the cone recently observed is less than 
three English miles, and the crater-opening still smaller. 
