INTRODUCTION. XV 



In exploring any coral-reef region with a steamer a good deal of planning 

 is necessary to enable one to see the interesting points of an atoll. The 

 lagoon can be explored only with the sun in certain positions ; one cannot 

 steam east in the morning or west in the afternoon. To take photographs 

 successfully the eastern face of an atoll must be explored in the morning 

 and the western in the afternoon, that the sun may strike shallows and 

 banks to define their limits and contrast their coloring with that of the 

 deeper navigable waters of the atoll ; and finally the programme must be 

 so arranged as to reach an anchorage before sunset, and an anchorage so 

 selected as to entail but little loss of time in leaving in the morning with 

 the sun in a favorable position either for further exploration or to pass 

 out of the channels of the atolls when the flats and banks flanking them 

 are well defined and rendered plainly visible from the angle at which 

 the sun shines upon them. 



A mere glance at the Admiralty Charts of the Maldives^ cannot fail to 

 show how very different in structure are Makimudu, Gaha Faro, Karidu, 

 Goifurfehendu, Rasdu, Toddu, Wataru, Fua Mulaku, and Addu from such 

 groups of atolls as North and South Male, Ari, North and South Nilandu, 

 Felidu, the Malosmadulu atolls, Miladummadulu and its northern extension 

 Tiladummati which might be called the Maldivian group of atolls par excel- 

 lence. Both these groups may be contrasted again to such atolls or groups 

 of atolls as Fadiffolu, Felidu, and Mulaku, which have as it were combina- 

 tions or modifications characteristic of the Maldivian atolls with features 

 common to a number of Pacific atolls. And finally they may be compared 

 to a third class of atolls like Kolumadulu, Haddummati, and Suvadiva, 

 which remind us of the larger atolls of the Pacific in the Marshall, Ellice, 

 Gilbert or Caroline Islands ; atolls noted for the absence of shoals and of 

 islands in the lagoons. The groups of small typical Maldivian atolls along 

 the forty to thirty fathom line of the great Maldivian plateau form an 

 agglomeration of small atolls along that belt resembling the great land-rim 

 reef flats of the Pacific atolls, but they have grown up as distinct parts and 

 are separated by deep channels. These small atolls vary in size from a 

 couple of hundred feet in diameter to atolls of seven miles in length. In 



1 B. A. Charts Nos. 66 a, h, c. 



