10 ASPECT OF A CORAL REEF. 



islands and reefs about, which, from the tropic of 

 Capricorn running through them, have been called 

 the Capricorn Group. The weather was very favour- 

 able, fine and clear, though very hot, as the sun was 

 almost vertical. Turtle were very abundant, espe- 

 cially the green turtle, and loggerhead, but only 

 one small hawk's-bill was taken. One night, Lieut. 

 Shadwell,* being on one of the islands observing 

 star altitudes, was actually obliged to place sentries 

 round him to prevent the turtle from running over 

 his artificial horizon as it lay on the ground. 



Although there is not much variety, there is con- 

 siderable beauty in a small coral reef when viewed 

 from a ship's mast-head at a short distance in clear 

 weather. A small island, with a white sand beach 

 and a tuft of trees, is surrounded by a symmetrically 

 oval space of shallow water of a bright grass green 

 colour, enclosed by a ring of glittering surf, as white 

 as snow, immediately outside of which is the rich 

 dark blue of deep water. All the sea is perfectly 

 clear from any mixture of sand or mud ; even where 

 it breaks on a sand beach, it retains its perfect 

 purity, as the large grains of coral are heavy and 

 do not break into mud, so that if a bucket full of 

 coral sand be thrown into the sea, it may be seen 

 gradually sinking like a white cloud without pro- 

 ducing any discolouration in the surrounding water. 

 It is this perfect clearness of the water which ren- 

 ders navigation among coral reefs at all practicable, 

 as a shoal with even five fathoms water on it can bo 

 * Now Commander Shadwell. 



