Lunar Sketches. 435 



LUNAR SKETCHES.— TRANSITS OF JUPITER'S 

 SATELLITES.— OCCULTATIONS. 



BY THE EEV. T. W. WEBB, A.M., E.E.A.S. 



In our last number we gave the comoaencement of a few- 

 original rough sketches of the lunar surface in the neighbour- 

 hood of firatosthenes and Copernicus, as a small contribution to 

 the materials which in great measure yet remain to be collected 

 for future comparison and study. We now propose to continue 

 our remarks upon the same interesting region. 



Eratosthenes. — The following notices may be referred to, 

 • concerning this crater. 



1858. Jan. 15. Sy^-inch achrom. " One-third of ring faintly 

 enlightened beyond terminator, and just connected with it by 

 a dimly lighted ascent," showing that the ground in the neigh- 

 bourhood of this great eruption had been upheaved like that 

 round Copernicus, though in a much less conspicuous degree. — 

 1861. April 18. 5|-in. achrom. Terminator through Tycho (48) 

 and Fontenelle (N. of Plato, 38) . " The wall a grand sight in 

 itself. Its N.W., W., and S. slopes to a considerable distance 

 are most curiously roughened with small hillocks and ridges, 

 whose general direction is concentric with the wall, and whose 

 appearance bespeaks a former semi-fluid condition," as, per- 

 haps it might have been added, their arrangement would rather 

 suggest the ejection of blocks than the flow of lava. Such 

 ideas, however, can only acquire weight from extended observa- 

 tion. — That the surface hues in and around it are of a decided 

 character appears from the following notices. 1864. Aug. 13. 

 5^-in. achr. " The wall still casts a penumbra on each side, 

 yet the interior begins to show local colour." Aug. 15. 

 (Id. 16h. before Full.) "Penumbra gone; a strange mixture 

 of light and duskiness on its site." How these shadowings are 

 arranged will appear, to some slight degree, from the two 

 following entries, which I quote just as they stand, having 

 given no further attention to the region, and being at present 

 unable to examine how far they admit of being reconciled. 

 1864. July 22. (3d. 1 7h. after Full.) 5 1 -in. achr. ie Eratosthenes 

 has its E. side filled with a dark lake, or rather, two such spots 

 joined by a narrower neck : a small dusky spot lies also at the 

 W. foot of the central hill." 1867. Nov. 8. (3d. before Full.) 

 9-J--in. silvered (< With " mirror. " Eratosthenes now all in local 

 colour; from point of junction of Apennines round the E. 

 semicircle, the outside glacis of wall shows a curious dark grey 

 border. This is penetrated in two places by the streaks of 

 Copernicus, which extend perhaps (but qu?) across Eratosthenes 



