152 EXTRAORDINARY REFLECTION. SECT. XVIII. 



Mundy in his Journal of a Tour in India probably 

 arises from this cause. A deep precipitous valley be- 

 low us, at the bottom of which I had seen one or two 

 miserable villages in the morning, bore in the evening a 

 complete resemblance to a beautiful lake ; the vapor 

 which played the part of water ascending nearly half 

 way up the sides of the vale, and on its bright surface 

 trees and rocks being distinctly reflected. I had not 

 been long contemplating this phenomenon, before a 

 sudden storm came on and dropped a curtain of clouds 

 over the scene." 



An occurrence which happened on the 18th of No- 

 vember, 1804, was probably produced by reflection. 

 Dr. Buchan, while watching the rising sun from the 

 cliff about a mile to the east of Brighton, at the instant 

 the solar disc emerged from the surface of the ocean, 

 saw the cliff on which he was standing, a windmill, his 

 own figure and that of a friend, depicted immediately 

 opposite to him on the sea. This appearance lasted 

 about ten minutes, till the sun had risen nearly his own 

 diameter above the surface of the waves. The whole 

 then seemed to be elevated into the air and successively 

 vanished. The rays of the sun fell upon the cliff at an 

 incidence of 73 from the perpendicular, and the sea 

 was covered with a dense fog many yards in height 

 which gradually receded before the rising sun. When 

 extraordinary refraction takes place laterally, the strata 

 of variable density are perpendicular to the horizon, 

 and if combined with vertical refraction, the objects 

 are magnified as when seen through a telescope. From 

 this cause,, on 'the 2(>'th of July, 1798, the cliffs of 

 France, fifty' "miles oi'f, were seen as distinctly from 

 Hastings as if they had been close at hand ; and even 

 Dieppe was said to have been visible in the afternoon. 



The stratum of air in the horizon is so much thicker 

 and more dense than the stratum in the vertical, that 

 the sun's light is diminished 1300 times in passing 

 through it, which enables us to look at him when setting 

 without being dazzled. The loss of light and conse- 

 quently of heat by the absorbing power of the atmos- 

 phere, increases with the obliquity of incidence. Of 

 ten thousand rays falling on its surface, 8123 arrive at a 



