276 REPORT— 1866. 



PosTSCEiPT. — 1867, April 12. 



In order to avoid any bias in the production of the outline, or in drawing 

 up the catalogiie, I purposely abstained, except in a few special instances, 

 from consulting either B. & M. or Lohrmann, so that the work, so far as it has 

 proceeded, is perfectly independent of the labours of previous selenographers ; 

 but while the foregoing sheets were passing throiigh the press, and after the 

 areas lY A* and IV A^ were engraved, I very carefully compared them with 

 Lohrmann's sections (the reader can make his own comparison with B. & M., 

 the corresponding portions of their Map being given in the Plate). As it is 

 not unlikely that some of the notes may be of interest, I take this opportu- 

 nity of adding them. A few have already been inserted. 



IV A". — 2. Eeaumur. Neither B. & M. nor Lohrmann give any objects 

 on this plain. 



7. The mountain-range on which this crater is opened is continued by 

 Lohrmann towards his mountain 34, Sec. I. (IV A^"^*^), where he gives an 

 opening into the plain west of IV A^-"* (Lohrmann's "W. Sec. I). IV A* '^, 

 IV A^ ^^ is in the direction of this mountain-chain, and it may probably be 

 the craterlet which Lohrmann shows on or near its south end. 



12, 13 are shown by Lohrmann as valleys opening into Hipparchus. In 

 his ' Topographic der Sichtbaren Mondoberflache,' Sec. I. p. 45, he says, 

 "The vaUey between 32 (IV A* ■''*') and 33 (IV A" ^8) unites the interior 

 floor of Hipparchus with the plain of the Mare vaporum." 



I have not met with an opening — certainly not with one that would easily 

 strike the attention — in the line of cliifs forming the N.E. boundary of 

 Hipparchus. If I have interpreted Lohrmann's language correctly, it would 

 appear that he considered that the floor of Hipparchus and that of the Mare 

 vaporum (Sinus Mcdii, B. & M.) were at the same level. Now in my obser- 

 vations of the region around IV A" '^ I found it depressed below Hipparchus, 

 the line of cliffs forming the partition. The only valley which I have given is 

 IV A-'^a^ south of IV A" '^ 1867, April 11, 1 found an opening in IV A* ^^ ; 

 the surface is, however, inclined towards IV A" ^ ' . 



Query. Is IV A" ^^ UocTced towards IV A" , as shown by Lohrmann, by 

 the mountain which appears to be the east side of the valley IV A* ^^ ? 



20. The mountain on the west of the south portion (IV A*"') appears to 

 be figured by Lohrmann at the mouth of the valley between 32 and 33 of his 

 Sec. I., but he does not in the slightest degree indicate the depression to the 

 east. 



25. This appears to be the N.W. side of the valley which Lohrmann men- 

 tions and figures in See. I. 87. 



32. This valley is shown by Lohrmann with a mountain-range within it. 

 The interior mountain-range I have not seen. Lohrmann shows the S.W. 

 mouth of the valley open, and exactly in the line of the valley TV AJ> ^^. 



43, 58. These formations are partially shown by Lohrmann with at least 

 two additional mountain-chains ; IV A" '*^ appears, according to Lohrmann, to 

 stand in a valley ; IV A* ^^ is ill figured. 



47. This cleft is well shown by Lohrmann, as well as the dark colour on 

 the surface which is very marked in the photograph. 



53, Lohrmann, in his text, p. 55, speaks of this valley as connecting the 



