ON MAPPING THE SURFACE OF THE MOON. 13 
largest craters on the area, [V A*16, TV A®14, and IV Af1%, It appears to 
have some relation to the ancient ring in its curvilinear direction. 
Movnrarn-Cuarms.—This term is employed to designate long series of 
mountains, either in unbroken lines or, it may be, detached mountains occur- 
ring in lines. A portion of such a mountain-chain just crosses the S.W. 
angle of the area. It commences at the junction of the 8. border of Ptolemcus 
with the W. border of Alphonsus, and rises into high peaks on the 8.W. 
border of Ptolemeus: it forms the N.E. border of <Albategnius, the ridges 
TV A$ ®7 and IV A¢® (described as crater-rills by Schmidt, and so catalogued 
in area IV A$) being the highest portions. From IV A¢* it passes onward 
to the N.E. border of Halley, where the peak IV A¢”° rises to an altitude of 
3543 English feet; it then passes along the cliff IV A”1%, facing the lower 
surface of the S.W. part of Hipparchus, and is interrupted by a succession of 
valleys, but is resumed in the mountain IV A"). At this part of the chain 
the hills are low compared with those on the borders of Ptolemeus and Alba- 
tegrius. Skirting the border of IV Af and IV A* ®, a plain intervenes 
between IV Af 2 and IV A & 7, from whence the chain is continued 8S. of the 
ring [IV A**3, With various interruptions, it can be traced as far as Sabine 
and Ritter. 
_ A short chain of cliffs occurs in the N. part of the area. The crests are 
generally transverse to the direction of the chain, which extends from IV Af 
to IV AF #4, 
Favrts*.—Several “faults” traverse this area—one, IV A”23 IV AB& &, 
connected with the great Tychonic system, and three connected with the 
smaller system, of which IV A”? appears to be the centre. The radiating 
character of the streaks from Tycho 
is well known. The “faults” con- PENS 
nected with IV A”? do not appear ail 
to be radiating, buttoconsist of three 
main ‘faults,’ one on the 8.8. W., 
the others on the N. of the South line} wa nag 
erater, both of which can be traced of faults ui 
to a considerable distance. The 
annexed diagram (fig. 1) is in- 
tended to show the general direc- 
tion of these “ faults,’ IV A” 36 
and IV A", as emanating from Bai) SEES 
IV A”?, also the fault IV A" 
TV A®®, diverging from IV A” wagie /\ 
in the direction of the mountain- KF 
ranges IV A", TV A713, Ty ages, 7OUE aT 3 phe 
Ty Af, &. The fault IVA" oe 
IV Af 20 TY A*” is specially de- 
scribed in the letterpress to areas aac a t ae 
IV A*, IV AS, p. 19, and Report Fi be 
Brit. Assoc. 1866, p. 255. Fault WA p20 
Parallel with TV A”, [V A820, Favle wapes 
IV A*” in the N. part of the area pay 
are two of a minor character, [V A® 5! and IV A8 #, which apparently are not 
connected with any point of owtburst. It is not improbable that these may 
be strictly contemporaneous with the main fault, and form portions of the 
same system. (See IV A* ”, pp. 30, 31.) 
® See note on p. 33. 
