18 REPORT—1868. 
elevation of the district of which it forms a part. This also points to its great 
antiquity, especially as the “ fault” separating Hipparchus from the district 
appears to be comparatively recent. 
**3(x). A crater on the E. part of the plain IV A*? IV A” }, position second 
order x 3, ‘0103 8.W. of photogram, M of B. & M., who mark it 7° of bright- 
ness. Lohrmann gives it 8°. It is 60 of his SectionI. Hede- Ag. 9. 
scribes it as small, and very deep. Its E. interior slope forms 
the W. slope of the mountain-range IV A*4, which is the first é | 
of a series of short mountains connecting [VY A*? with TV Af l4, 
It, as well as IV A*14 and IV A®!9, is very deep, the shadow 
being still gibbous when the morning terminator has just passed Copernicus. 
The proportion of shadow to illuminated interior, when the longitude of the 
morning terminator=21° E., is as 1 to 1-833. See fig. 2. In the following 
engravings, representing the proportion of shadow to illuminated interior, 
the extent of shadow in all cases is equal to 1, but not upon the same 
scale, neither are the craters given on the same scale. IV A? is the 
fourth crater in order upon area IV Af, Diameter 6°25; longest dia- 
meter on a line passing through IV A*#9 8”:02, mag. 0°42. It appears as 
a white spot under a high illumination. 
1868, May 1° 8" 0" G. M. T., I observed with the Crossley equatorial a 
white spot S. of IV A®#, which was also seen with the Royal Astronomical 
Society’s Sheepshanks telescope, No. 5, aperture 2°75 in., power 100, on May 
304 9" 30™ G. M. T., 1868.—[W. R. B.] 
*4(x). A short mountain-range forming part of the E. boundary of the 
plain ITV Af? TV A’3, The N. end of this mountain-chain is \ of B. & M., 
whose measures give 6177 English feet, or 1883 French metres, for its alti- 
tude. Length of crest 8-48. The breadth of base includes the depth of the 
crater IV A £3, and is accordingly difficult to measure. Its E. slope appears 
to be very gradual. 
t5. The 8.E. of B. & M.’s five peaks on IV Af! N. of IV AF4. See 
ante, p. 16. 
+6. A peak between IV A*5 and IV A&7. 
7. A peak between IV A*® and IV Af 8, 
+8. A peak between IV A®7 and IV AP ®. 
+9. The N.W. of B. & M.’s five peaks on IV A? 1. See ante, p. 16. 
*10(x). A short mountain-range parallel with IV A**. Length of crest 
6"-25. It is situated near the point of intersection of two “ faults,” IVA” 73 
TV Af ®, and IV Af *, the latter of which, although not so well marked as 
the “fault” IV A” 1! TV A&?0 TV A*”, can be easily traced as parallel with 
it on Rutherford’s photogram. 
It is difficult to determine whether Lohrmann really intended the S. ex- 
tremity of his 63, Sec. I., to represent IV A* 1°. Ifhe did, then he has an addi- 
tional range between 63 and 60, which is not apparent on the photogram. 
Ifhe did not, then his range 63, Sec. I.,is much longer than it ought to be. The 
cliffs between IV A*? and IV Af !* are very indifferently shown by Lohrmann. 
The boldest are certainly in the neighbourhood of [V Af*, His 59, See. I. 
(IV A ®°), which he has made the boldest, is certainly the lowest, as well as 
the last of the chain connecting TV A** with IV Af14. The direction of this 
chain is S.E—N.W. See also IV Af *4, post, p. 32. 
*11(x). A formation somewhat of the character of a circular hill with a 
depression of the nature of a crater nearly central. The E.N.E. boundary 
consists of a high mountain-range, IV Af *?, which, with IV A*9, form a 
rampart parallel with the W.S8.W. wall of Rheeticus. The interior of [TV Af 1 
a ae ee 
— ee a 
