TELESCOPIC PHASES. 399 



sor Nichol, " to conceive a more remarkable contrast than chaptfr 

 that between tlie appearance of the moon to tlie naked -^x^'UL 

 eye, and that whicli she presents to the telescope, wlie- 

 ther in quadrature, or when she is full. Instead of a 

 plain and bright surface, sending from all its parts an 

 illumination not far from equable, we discern a body 

 of most strange character, broken by irregularities which, 

 in extent ajid form, present few analogies with the moun- Mountainous 

 tainous regions of our own globe. The reality of these, ''^^"^"^ 

 as well as the singularity of their contours, the briefest 

 glance at the crescent luminary is sufficient to establish. 

 The incomplete edge is, in that case, under the influence 

 of a morning or evening light ; and all the phenomena 

 of lightened peaks, dark valleys, and long shadows, which 

 occur in a broken district of the earth in such circum- 

 stances, are there distinctly visible, but on a scale far 

 more grand. Look, for example, at a scene near Tycho, 

 where the sun is shining obliquely on the rims of tremen- 

 dous pits, or circular caverns, some of which are as deep 

 as Mont Blanc is high, — and say, if that beauteous lumi- Indications 

 nary, notwithstanding her placid smile, has not, even as sions. 

 our ov.n shattered globe, undergone a troublous his- 

 tory ! The representations given, so far from being ex- 

 aggerated, are but feeble approximations to the reality ; 

 nor can the moon in any phase be painted. The living 

 glory of the real object cannot be transferred to the can- 

 vass — no shade or colouring can accomplish that ; but 

 the features which are concerned with our scientific in- 

 quiries may all be exactly preserved. 



" It will be seen," the author then remarks, in refer- Adequate 

 ring to his illustrations of the appearance of the satellite, obsen-ation. 

 " that a complete survey of the moon's surface is quite 

 within our reach. No elevation of any magnitude, when 

 on the EDGE, can fail to cast a long shadow, — the rays of 

 the rising or setting sun then falling on \i\ery obliquely; 

 and not only does this shadow reveal the existence of the 

 elevation, but its length, which can be accurately mea- 

 sured, must evidently indicate the height of the moun- 



