16 ; REPORT—1868. 
is separated from the short range IVY A* * by a break or gorge, through which, 
under favourable circumstances, the sun has been seen clearly shining. 
IV Af‘ forms the E. rim of the crater TV Af3, at the N. end of which 
another break occurs. Beyond this break is seen the mountain-range IV Af !. 
The direction of ITV Af* and IV Af! is nearly at right angles to that of 
TV Af 3%, B. & M. describe and figure upon IV Af! five mountain-peaks, 
IV A®> to TV A®9%, They are inserted in the catalogue upon their authority ; 
but, not haying seen them, I haye not yet inserted them upon the map. There 
are no traces of them upon Rutherford’s photogram. B. & M. speak of them 
as being like a string of pearls. It is probable they may be detected a short 
time after sunrise. At the western end of IV A! another break in the boun- 
dary occurs. This is succeeded by the range IV Af18, TY AY’ 1—the two 
ranges LV Af! TV Af, and IV A”! forming a gentle curve, which is con- 
tinued by the depression IV A’4, This depression completes the boundary— 
the plain IV A*?, IV A” being quite open towards the 8. W. 
1864, Dec. 5, 6" 30™ to 7° 55™, this region was carefully observed with 
the Royal Society’s achromatic of 43-in. aperture, power 230. The details 
recorded then mostly agree with the features as seen on the photogram. A 
few have not been recognized, of which the principal are as follows :—‘ The 
western part of the boundary was seen to consist of three detached rocks, of 
which the southern one was rather elongated. The mountain-arm IV Af *9 
was observed to end in an irregular boss or club-shaped elevation, of less 
brightness than the mountain-arm.” 
**2(x). The E. part of the plain enclosed on the W. by the depression 
IV A” 4, on the N. by the mountain-ranges IV AY}, IV Af 18, on the E. by 
IV A®! and IV A®4, and on the S.E. by IV AF 39, 
This plain is quite open towards the S.W., and has upon it the following 
objects :—The crater IV A® 3, which is the most conspicuous; a somewhat 
short elevated ridge, probably Lohrmann’s 61 of his Sec. I., which I do not 
recognize on the photogram ; and two minute hillocks between the ridge and 
crater. These hillocks are recorded in Obs. Bk. p. 164, No. 315, 1864, Dee. 
5, 7.15 G.M.T. They are neither inserted in the map nor symbolized, as I 
do not find a seeond observation of them, and, not having made a sketch at 
the time, I am uncertain as to their position. I have the following note :— 
*‘ With the exception of 60 and 61, Lohrmann gives the surface of this forma- 
tion smooth. At present I do not see any other inequalities than the two 
minute hillocks.” On Rutherford’s photogram I find two objects to which 
the hillocks observed in 1864 may answer—IV A® %, described as a “hillock 
on the plain, and IV A® 91, a shallow depression.” It is probable I saw only 
the slope of the depression, which I regarded as that of a hillock. 
This plain on Rutherford’s photogram has greatly the appearance of a large 
ancient crater which has suffered from irruption and become nearly filled. 
If such has been the case, the wall has been broken through on the 8.W., the 
open portion facing a somewhat smooth tract, agreeing in this respect with 
the numerous ruined craters (as they appear to be) on the borders of the 
Maria. The plain is interestingly situated with regard to Godin and Agrippa. 
The crater TV Af, as well as the cliffs between IV Af3 and IV Af ™, are 
probably of more recent origin than the plain. The depressions IV A’ 4 and 
IV A* 41 at the extremities of the N.W. and S.E. ranges are remarkable. 
The occurrence of mountains standing in shallow depressions is not uncommon 
in some parts of the moon; it is a curious feature, and deserves careful con- 
sideration as well as observation. 
A very remarkable and interesting feature is connected with this plain, 
ers ieee 
