254 REPORT — 1866. 



Rhaeticus to the S.W. end of IV A** ^^, is parallel with the line of fault 

 IV A« 42. 



The surface on the east of the south part of the line of fault is very dif- 

 ferent. Between it and the mountains IV A* ^^ and IV A* ^l^ it appears to 

 be generally smooth, but diversified by rays which in a measure, although not 

 very marked, converge to IV A* ^ as a centre. Between IV A* ^ and 

 IVA«38 is the lucid spot IVA«4l. 



43. A mountain-ridge in the continuation of the line of fault IV A* ^^j 

 direction S. by W., face toward W. by N., length 23"-0. It has 

 upon it three craterlets. 



44. The south of two craterlets near the south end of IV A« ^3 y.Q^ 

 mag. 0-06. Not in Lohrmann. 



45. The north of two craterlets near the south end of IV A"'^^ l"-0, 

 mag. 0-06. Not in Lohrmann. 



46. A craterlet on the north part of IV A« 43 i-'.q, mag. 0-06. 



47. A deep cleft on the south border of the Sinus Medii. 

 The east side of this cleft is a continuation of IV A" ^3. 



48. The south part of the second wall of Rhaeticus. 



49. A line of fault extending fi'om the south part of IV A? ^^ to the 

 west border of Rhaeticus, where it intersects the fault IV A" ^^> 

 IV A/3 20^ ly A« 72, The portion between IV A« lo and IV A* » 

 (Rhaeticus) is on the " Ray from Tycho." 



50. A cliff on the north part of the west border of IV A"* ^^. 

 **51. The mountain-arm west of IV A* ^, IV A^ ^^, the north part. 



52. A curved mountain-range extending from IV A* ^^ to the east part 

 ofthe vaUeylVA^'^g. 



53. A short shallow valley on the north border of IV A* ^, length 8"-56, 

 breadth 9"-99. Lohrmann's Sec. I. 90. 



54. A chain of mountains extending from the west border of IV A* ^ 

 to the south of Reaumur, length 1 3"'0. Shown by Lohrmann. 



55. A mountain between IV A<* ^^ and Reaumur, also between IV A* '^ 

 and IV A« 80. 



56. A mountain N.W. of IV A<^ 55. 3".5. 



57. A craterlet on the south border of Reaumur. 3"-8, mag. 0-26. 



58. A valley east of and parallel with IV A* ^3. 



This valley is very interestingly situated with regard to Rhaeticus. It is 

 about as far from the east border of Rhaeticus as the west portion of the second 

 wall is from the west border, but unlike this portion, in its being depressed, 

 instead of elevated above the surface. The directions of the two are also dif- 

 ferent, the high west ranges being S.S.E., and the depressed valley south by 



west. Their directions produced meet at the south part of IV A^ ^^, but 

 there are no indications of any connecting formations. The space between 

 Rhaeticus and IV A* ^^ ig occupied by rugged ground, about the middle of 

 which the ridge IV A** ^3 ig elevated. 



IV A* ^8 lies veri/ exactly in the line of depression IV A" ^ ^^ ly A" ^'^, 

 iyA«i2^ the direction of which is south by Avest. This line of depression 

 intersects VIII. S.S.W. in the mountain IV A^ ^9. 



