1868.] 



the Surface of the Moon, 



235 



sures which range hke great faults in our earthly strata for five, ten' 

 twenty, and sixty miles, but is conspicuously proved by the great broken 

 ridges of mountains which, under the names of Alps, Apennines, and 

 Ripheean chains, make themselves known as axes of upward movement, 

 while so many of the craters near them speak of local depression. I have 

 not been able to discover in these great' ridges any such marks of succes- 

 sive stratification, or even such concatenation of the crests, as might sug- 

 gest symmetrical and anticlinal axes. The surface is, indeed, as rough and 

 irregularly broken as that of the Alps and Pyrenees, and marked by as ex- 

 traordinary transverse rents, of which one, in the Alpine range near 

 Plato, is a well-known example. Must we suppose these mountains to 

 have undergone the same vicissitudes as the mountain-chains of our globe 

 — great vertical displacement, many violent fractures, thousands of ages of 

 rain and rivers, snow and glacial grinding ? If so, where are the channels 

 of rivers, the long sweeps of the valleys, the deltas, the sandbanks, the 

 strata caused by such enormous waste ? If the broad grey tracts were 

 once seas, as analogy may lead us to expect, and we look upon the dried 

 beds, ought we not to expect some further mark of the former residence of 

 water there than the long narrow undulations to which attention has already 

 been called as resembling the escars of Ireland ? 



In any further attempts of my own to contribute facts tov/ard the survey 

 of the moon, now again taken in hand by the British Association, I shall 

 probably select for careful work some particular features, such as the 

 mountains in the midst of a large crater, the bosses and cup-like hills on 

 the outward slopes of such a crater, the rents in mountain-ridges, and 

 the low winding banks which appear on the broad grey tracts. But, 

 for those who desire to perform a work of high value, I would earnestly 

 recommend a strict reexaminalion of every element in the great picture 

 of Copernicus, for which we are indebted to the Roman Astronomer. 



The paper was accompanied by twelve drawings, which were exhibited 

 to the Society, and of which the following is a list : — 



No. 1. Sketch of Gassendi taken in 1852, at Birr Castle, with the great 

 telescope of Lord Rosse. 



No. 2. Sketch taken in 1852, at York, with an achromatic by Cooke, of 

 2*4 inches aperture. 



No. 3. Sketch taken in 1853, at York, with an achromatic by Cooke, of 

 61 inches aperture. (Morning.) 



No. 4. Sketch taken in 1862, at Oxford, with an achromatic by Cooke, 

 of 6 inches aperture. (Evening.) 



No. 5. Working plan of Gassendi and scale. 



No. 6. Free-hand sketches to illustrate the mode of working for general 

 effect. Oxford, 1 864. 



No. 7. Theophilus, Cyiillus, and Catharina, taken at Oxford in 1862. 

 This is about the third attempt. 



