Curiosities of Science. 163 



at noon was denoted by rays of light shooting into the sky above the 

 woods. 



The moon in the long nights was a most beautiful object, that satel- 

 lite being constantly above the horizon for nearly a fortnight together. 

 Venus also shone with a brilliancy which is never witnessed in a sky 

 loaded with vapours ; and, unless in snowy weather, our nights were 

 always enlivened by the beams of the aurora. 



INTENSE HEAT AND COLD OF THE DESERT. 



Among crystalline bodies, rock-crystal, or silica, is the best 

 conductor of heat. This fact accounts for the steadiness of 

 temperature iii one set district, and the extremes of Heat and 

 Cold presented by day and night on such sandy wastes as the 

 Sahara. The sand, which is for the most part silica, drinks-in 

 the noon-day heat, and loses it by night just as speedily. 



The influence of the hot winds from the Sahara has been 

 observed in vessels traversing the Atlantic at a distance of up- 

 wards of 1100 geographical miles from the African shores, by 

 the coating of impalpable dust upon the sails. 



TRANSPORTING POWER OF WINDS. 



The greatest example of their power is the sand-food of 

 Africa, which, moving gradually eastward, has overwhelmed 

 all the land capable of tillage west of the Nile, unless sheltered 

 by high mountains, and threatens ultimately to obliterate the 

 rich plain of Egypt. 



EXHILARATION IN ASCENDING MOUNTAINS. 



At all elevations of from 6000 to 11,000 feet, and not unfre- 

 quently for even 2000 feet more, the pedestrian enjoys a plea- 

 surable feeling, imparted by the consciousness of existence, 

 similar to that which is described as so fascinating by those 

 who have become familiar with the desert-life of the East. The 

 body seems lighter, the nervous power greater, the appetite is 

 increased; and fatigue, though felt for a time, is removed by 

 the shortest repose. Some travellers have described the sensa- 

 tion by the impression that they do not actually press the 

 ground, but that the blade of a knife could be inserted between 

 the sole of the foot and the mountain top. Quarterly Review, 

 No. 202. 



TO TELL THE APPROACH OF STORMS. 



The proximity of Storms has been ascertained with accuracy 

 by various indications of the electrical state of t'he atmosphere. 

 Thus Professor ^Scott, of Sandhurst College, observed in Shet- 

 land that drinking- glasses, placed in an inverted position upon 

 a shelf in a cupboard on the ground-floor of Belmont House, 



