SHOOTING STAR IVHRAGE. 303 



proceeded, I discovered a most magnificent shooting star, 

 passing sloivly in an oblique direction through space, with an 

 immense tail attached to it, and emitting sparks of dazzling 

 light. The fire by which I sat was exceedingly bright, and 

 the moon clear and brilliant, yet they were both totally 

 eclipsed by this immense body of light. Its great beauty and 

 brilliancy might perhaps be best realized by saying that it 

 was like a star of the second or third order when compared 

 to the moon at full. 



After a time, the pasturage being nearly exhausted in the 

 neighborhood of the Hountop, we removed our camp a few 

 miles southward to another periodical river called the Aam- 

 houp. During our stay here we observed some very strik- 

 ing and singular horizontal refractions of the air. Once I 

 saw an ostrich walking on the horizon line, while its double 

 — clear and well defined — appeared immediately above it. 

 Both the ostrich and its double, moreover, were divided into 

 three different portions by as many different strata of air. 



Again : regularly every morning, for nearly a months the 

 projecting ledge of a rock was converted into the semblance 

 of a splendid and embattled castle. As the atmosphere be- 

 came uniformly heated, the mirage melted away into a soft, 

 watery haze. 



In usual refractions the inverted image of an object gen- 

 erally appears above the object itself, but occasionally the 

 effect is reversed. Captain Scoresby, the well-known Arctic 

 navigator, once by these means discovered his father's vessel 

 the day before it actually came in sight. 



It has long puzzled the learned to account for the mirage. 

 I believe, however, it is now pretty well known to arise from 

 the unequal density and temperature of the lower strata of 

 air. 



The abundance of good water and pasturage had enabled 

 our cattle to get into excellent condition ; and as the season 

 was now far advanced, and I was sufficiently well to travel, 



