Lunar Sketches. 437 



viscous material, agitated just before consolidation." The 

 remarkable appearance here referred to is not confined to this 

 region. I have traced it in others of the so-called lunar seas : 

 in the M. Nubium (M), the M. Humorum (N), the if. Nectaris 

 (0), and near the E. shores of the M. Serenitatis (E) ; further 

 search will probably detect it in other situations; and it is 

 probably one of those significant features which deserve pecu- 

 liar attention in any speculation as to the probable origin of 

 existing configurations. Very imperfect at present such specu- 

 lations must necessarily be ; and whether they may ever 

 assume the proportion of a consistent theory will depend first 

 on diligence of examination, and next on the care and im- 

 partiality exercised in dealing with the materials of thought. 

 At present they are but guesses and inquiries, worthy of being 

 recorded only so long as they make no further pretension. 



Stadius. — The curious discovery of a number of minute 

 craters within this slight enclosure was made by Dr. Dobie, of 

 Chester, with a 5^-in. object-glass in the summer of 1863. His 

 obliging communication of it to myself led me to wish for an 

 examination of the region, which I was unable to accomplish for 

 a considerable time ; the illumination suitable for such minutiae 

 being always transient, and the air not frequently sufficiently 

 steady. However, 1865, Jan. 6, when the terminator was 

 passing through the E. side of lieinhold (31) and Bullialdus 

 (60), and definition, with haze and a cold N.W. breeze, was 

 fine, but rippled over, and very unsteady, my 5^-in. achr. 

 enabled me to make out 10 or 12 minute pits, similar to those 

 in the crater-chains of Copernicus, but smaller, and without 

 distinct rings; they were chiefly in S. and W., and. none, I 

 thought, in the centre. I detected them again 1866, Feb. 23, 

 the terminator having passed beyond Plato (38) and Tycho (48) 

 by the amount of their own diameters ; and I have since seen 

 them with my beautifully defining 94--in. silvered mirror, but 

 not under the favourable circumstances which they require. 

 May we imagine that these are of modern date ? The large 

 maps of B. and M. and Lohrmann contain only one small crater 

 in the S.W. part of the floor of Stadius, a crater which I think 

 I have seen pre-eminent among the rest ; but the others might 

 easily have escaped the small aperture of B. and M., and Lohr- 

 niann's Sections and letterpress unfortunately do not extend so 

 far : we must, therefore, suspend our opinion, and allow the 

 probability to be decided by less ambiguous evidence elsewhere. 

 In one respect this region is worthy of attention on the part of 

 those who have a clear optical command of it : its circumscribed 

 nature enables the little included cones to be counted and 

 drawn with greater certainty than might be the case in a less 

 definite area. We proceed now to the • 



