54 A NATURALIST ON THE " CHALLENGER." 



the town where garbage was thrown, and were often to be seen 

 hunting over the refuse heaps in company with ravens and 

 crows. Some small finches were common in flocks on the hills 

 and some small hawks. 



At the periods of migration, quails are extremely abundant 

 on the island, as at St. Jago, and often afford good sport to naval 

 officers ; they are, however, mere birds of passage here, and there 

 were none at the time of our visit. Of sea birds I saw a cor- 

 morant and a bird which looked in the distance like a Merganser. 

 Gulls and terns were absent entirely. 



I was told that the goats which are wild on the island, have 

 all attained a red colour resembling that of the rocks, and that 

 they were hence very difficult to find and shoot ; I, however, 

 saw none myself. 



August 6th. — The island of Fogo was in sight ; it appeared to 

 our view as two truncated cones, showing out against the sky 

 above a bank of clouds. One of the cones, which is 9,000 feet 

 in height, is much higher than the other, and has a tiny secondary 

 cone at one edge of its main terminal crater, just like Pico in 

 the Azores. The volcano is active, but had no smoke issuing 

 from it as we passed. The peaks showed out against the sky 

 far above the horizon. 



I was constantly astonished at the great height above the 

 horizon to which high mountainous islands seem to rise when 

 viewed from a long distance at sea. This appearance was 

 especially marked in the case of the Peak of Teneriffe. One is 

 apt to scan the region of the horizon, when the Peak is just in 

 sight far too low down, being accustomed to search for much less 

 elevated objects which become visible directly they rise above 

 the horizon. The line of sight traversing in that direction, 

 clearer air allows the summit of the high distant mountain to 

 be visible long before the base. 



When we were approaching the Azores, we sighted the island 

 of Corvo at a distance of sixty miles. The island appeared re- 

 markably near, being thrown up high above the horizon probably 

 by atmospheric refraction. The distance of the island was 

 guessed from its appearance at from seven to twenty-five miles. 

 The island disappeared from view before mid-day by a change in 



