Mr. J. Nasmyth on the Telescopic Appearance of the Moon, 311 



crater and that of another, this being proved by the fact of the cir- 

 cular mound of the one overlaying that of the other. [The author 

 here introduces a pen sketch illustrating this remark.] 



Next to the circular form of the craters, the author considers that 

 there is no feature more striking than the small cones or mounds 

 which we observe in the centre of most of the craters. These he 

 considers to be the result of the last expiring efforts of the volcanic 

 action, as we find it to be the case in Vesuvius and other terrestrial 

 volcanoes. Other cases exist in which there is no such central cone ; 

 but these may have resulted from the more sudden termination of 

 the volcanic action which had permitted the fluid sooner to float 

 across the bottom of the crater, and to form that plain, smooth sur- 

 face which may be seen in a few cases. One has been, however, 

 observed by the author in the upper part of the right limb of the 

 moon, in which the lava had apparently kept flowing up so gently 

 to the last as to leave the crater brim-full. [This is illustrated by a 

 pen drawing.] The ruts or channels which may be distinctly ob- 

 served in the sides or banks of the outside circular mounds, and which, 

 frequently extend to a considerable distance, prove that the matter 

 discharged has not been entirely of a solid nature. Blocks of solid 

 materials also appear to have been discharged with vast force and in 

 vast quantity. They may, in many cases, be observed lying about 

 the bases of the larger craters, where the surface is rendered quite 

 rough by the quantity of such detached fragments. 



The last peculiarity adverted to by the author consists in the 

 bright lines which generally converge to a centre, and in which we 

 frequently find a crater of very considerable magnitude. " Tycho," 

 "Copernicus," and " Kepfer," are remarkable examples of this ap- 

 pearance. The material of these bright lines is evidently of a much 

 more reflective nature than the contiguous or general surface of the 

 moon, and in most cases the interior of the crater to which they 

 converge is equally resplendent. The author considers them to be 

 derived from the same original cause which produced the central 

 volcano from which they appear to diverge. It appears to him that 

 they are produced by the flow of the molten lava through the vast 

 ci'acks resulting from the great primary upheaving action which had 

 burst upwards the solid surface of the moon, cracking it as a pane 

 of glass does when broken by any pointed object. The centre of 

 disruption has evidently been under the great central volcano. The 

 cracks have diverged on all sides from this centre of action ; and the 

 molten lava immediately flowing up would come forth in greatest 

 quantity from the centre, and there result in and produce the great 

 crater, while the radiating cracks would yield smaller portions simul- 

 taneously all along their course, however exteiided. 



II. Observations of the Solar Eclipse of 1843, December 21, made 

 at the Observatory of Trevandrum. By John Caldecott, Esq. 



The account of the eclipse is communicated in a letter to Mr. 

 Baily, dated February 21, but was unfortunately too late for the 

 mail of that month. Mr.. Caldecott having satisfied himself that the 

 eclipse would be total, in latitude 1 1° 45' north, and longitude S'^ 3*" 

 east, determined on proceeding to the neighbourhood of Tellicherry 



