5i6 THE POPULAR SCIENCE MONTHLY. 



last decade is Nelson's " Moon," the accompanying chart in sections 

 giving the principal features of the planet's surface. Nasrayth and 

 Carpenter's " Moon," illustrated by fine photographs of prominent in- 

 sulated peaks, mountain-ranges, and crateriform mountains, and Proc- 

 tor's "Motions, Aspect, Scenery, and Physical Condition of the Moon," 

 furnish delightful and instructive text to the general reader. 



Very beautiful drawings of single craters, viewed under high power, 

 have been made by Secchi, Nasmyth, and Carpenter. Bertch, Arnauld, 

 Temple, and Harriot, a young English astronomer, have given us topo- 

 graphical lunar drawings of considerable merit. 



The greatest change in lunar illustration occurred in the application 

 of the telescope to photography. The moon, sighted by a telescope 

 provided with a meniscus lens for the collection of the actinic rays, 

 and kept in the field by the driving-clock, casts her image on a sensi- 

 tive plate, which, being developed, gives all the numerous details of 

 the lunar surface dimly and minutely, to be stlre, but capable of 

 enlargement and printing to apparent life-size. 



Draper photographed the moon in 1840 ; Bond, in 1850 ; De La 

 Rue and Rutherfurd, in 1857, the former discovering that the pictures 

 could be combined in the stereoscope so as to appear globular. Pho- 

 tographic representations of the moon, in her various phases, are emi- 

 nently picturesque, though lacking distinct detail ; they are, however, 

 correct, for, granted that the apparatus is properly adjusted, the sun 

 paints with perfect truth. 



Nelson's maps of the moon were first done in water-color. Some 

 have also been done in this vehicle by the " Moon Committee " of the 

 Royal Astronomical Society of London." It has been reserved for 

 Henry Harrison, a young American astronomer and artist, to paint 

 the first and only true telescopic portrait of the moon in oil-colors. 



" Not difiicult to do ! " exclaims the uninitiated observer. 



*' Impossible ! " returns the scientist. "No one can paint the moon 

 in detail." 



Nevertheless, our aesthetic astronomer set to work to paint the six 

 phases, which would give a portrait not only picturesque, but so true 

 to details and coloring that it could be offered to the scrutiny of eyes 

 long practiced in the nightly study of the orb itself eyes that would 

 be quick to detect the absence of the smallest crater, the presence of a 

 superfluous peak. 



After the professional duties of the day, Mr. Harrison, when the 

 weather was propitious, passed his time in making observations of the 

 heavens. Seated at the telescope, he would pass hour after hour, study- 

 ing the surface of the lunar orb. 



On one of these occasions, a summer evening, singularly calm and 

 clear, his wife joined him. Sitting for some time completely absorbed 

 in the brilliant spectacle, she at last exclaimed : " Henry, paint that, if 

 you can ; it is beautiful beyond description ! " 



