340 FROM NEBULA TO NEBULA 



Sun moves across the lunar sky, they shift from the eastern to 

 the western side of the craters. In the southern hemisphere 

 they circle round the crater by way of the south, and in the 

 northern by way of the north. Even quite near the equator the 

 circling occurs to a certain extent. The whiteness is frequently 

 due to small irregularly shaped bright areas, which are some- 

 times related to small craters, but more often they lie on some 

 steeply inclined interior slope. They rarely occur on the outer 

 slopes of the craters. 



Let one more quotation suffice, this time from the 

 article of Professor Eussell W. Porter, entitled Moon- 

 scapes (Pop. Astr., No. 238), which is embellished with 

 three instructive ideal views of the moon that cannot be 

 distinguished from Arctic landscapes, or rather snow- 

 scapes. He says: 



Our nearest neighbor, the moon, is a case in point. The 

 writer, in viewing her surface through his sixteen inch reflector 

 in the comfort of a closed observing room, has frequently caught 

 himself transported to that body, and, in imagination, viewing 

 her scenery from some crater lip or the vast expanse of one of 

 her sea floors. Having himself spent many years above the Arctic 

 Circle, he was struck by a strange likeness of the moon's general 

 aspect to our own polar regions. The long reaches of the frozen 

 polar ocean, traversed by immense pressure ridges and tidal 

 cracks, the dazzling whiteness and clear cut shadows, the desola- 

 tion and loneliness all seemed to find a counterpart in the lunar 

 appearance. The accompanying moonscapes were the natural out- 

 come. 



CUEEENT THEOEIES KEGAEDING THE LUNAE SURFACE 



THE PLUTONIC OE VOLCANIC THEOEY. Since, in our 

 superlatively practical age, we find astronomers, even 

 those of an agnostic turn, ready to subscribe to such 

 superstitions as uncaused motions, self -rotating nebulae, 

 and the like, it is easy to excuse Galileo and his contempo- 

 rary sympathizers for accepting, out of hand, the pre- 

 posterous notion that the so-called craters of the moon 

 are veritably volcanic. But that such an infantile idea 

 has been able to survive the discovery of the mechanical 

 equivalent of heat and command at the present moment 

 the confidence of the great majority of learned scientists, 

 is to me one of the most cryptic of modern mysteries. 



