ON MAPPING THE SURFACE OF THE MOON. 19 
dips on the E.N.E. from the W. edge of IV A* to the W.S.W. foot of 
IV Af*; the ridge IV Af ® crosses [LV Af 1! from S. to N. 
Lohrmann describes and figures this formation as an enclosed plain, J of 
See. I. with central mountain, the surrounding mountains being 62 (IV Af ®), 
63 (LV A®*4), and 64 (1 A*?5) of his Sec. I. He also speaks of two low 
rows of mountains between them. He says that in the midst of the interior 
plain a small central mountain is elevated. There is certainly nothing of the 
kind on Rutherford’s photogram, March 6, 1865, neither plain nor central 
mountain. On the W. of IV Af! is a hollow, IV A? 49, communicating with 
a semicrater, neither of which are shown by Lohrmann. The boldness with 
which the formations IV A?! and IV A** appear on the photogram is quite 
absent in B. & M.’s large map. IV A?" is more distinct in the small map, 
1837, but shown as a plain without a central mountain. 
1867, Dec. 3, 10". Royal Astronomical Society’s Sheepshanks telescope, 
No. 5, aperture 2°75, power 100. Identified TV A’ 29 and IV Af ®, the E. 
mountainous boundary of the two formations IV A*"™, TV Af 49, answering 
to Lohrmann’s 62, Sec. I., which are laid down correctly byhim. Also TV Af 57 
and IY Af 4, the W. boundary answering to his 63, Sec. I. The two low 
mountain-chains spoken of by Lohrmann I failed to identify, but I saw on 
the moon a mountain, between the two mountain-boundaries above specified, 
which is not the central mountain of J, Sec. I., but the mountain-ridge 
IV Af of IV AF, It is probable that the mountain-ridge of IV Af ! is 
the E. of Lohrmann’s two low ridges; and between this and his 63, Sec. I., 
is the depression IV A* 4, not shown by him, and, instead of a plain 
and central mountain between the ridges IV Af ® and IV Af 29 TV A852, 
the 8. part of the space is filled with the crater IV Af, and the N. part 
dips to the N. angle of the formation IV A*" I Af 30._/W. R. B.] 
1868, May 1° 8" 45" G. M. T.; Crossley equatorial 7-3 inches, power 122. 
Crater-row pretty well defined; IV AS! very distinct, with the crater 
IV A® upon it. The surface of the hill is in the form of a tableland, 
TV Af?) and IV Af rising higher on the E., the W. slope of IV Af & 
descending to the hollow. 
It is very possible that Lohrmann regarded the tableland as an enclosed 
plain. The question now is whether the crater IV A* 2 was regarded by 
him as a mountain. I do not see an exterior shadow on the E.; fig. 3 is too 
dark on the E. and N.E. The shading is not intended to indicate shadow, 
but the slope of the mountain on the N.E.—[W. R. B.] 
As in the case of Linné, it may possibly be considered that both Lohrmann 
and B. & M. are in error. It does not appear that B. & M. mention the 
formation. The following is a translation by the Rev. T. W. Webb. of Lohr- 
mann’s notice (Topographie der sichtbaren Mondoberfliche, erste Abtheilung, 
. O1):— 
ar ($ 47. 1.) This landscape lies under 7° of W. longitude upon the equa- 
tor, and is circularly encompassed by the high mountains 62, 63, and 64. 
Between these mountains, however, are also found two lower rows of moun- 
tains, going parallel with 63, that more closely encompasses I. In the 
middle of the inner plain a small central mountain raises itself.” 
*12(x), The central craterlet in IV A® 4 4-47, mag. 0:26. The ninth in 
order upon area IV AF, position second order x 12 on W. rim. This crater- 
let appears to be destitute of a raised wall, and is more of the cha- Fie. 3 
racter of a dimple at the summit of the circular hill composing ~ S>— 
IV Af, With a morning terminator advanced a little beyond Q 
Copernicus the shadow is crescentiform ; proportion to illuminated 
