188 '■ ALBATKOSS " TROPICAL ]'A.('IFIC EXPEDITIOX. 



TONGATi-BU. 



PUde^ 115-1 IS, 21.}-21o. 



The southern cluster of the Tonga group ^ (PI. 214) consists of the islands 

 of Tongatabu (PI. 215), and its satellites, with the shoals extending to the 

 north about thirty miles from the harbor of Nukualofa, the soundings on 

 the northern part of the bank varying from 20 to 40 fathoms ; two inden- 

 tations of shallower water rim into the plateau, the one from the east, 

 south of Dido Shoal, towards Ava Lahi Pass, and the other, west of Eua 

 iki, forms the main entrance into the harbor of Nukualofa. 



The island of Tongatabu is about eighteen and a half miles in greatest 

 length. From Cook Point the southwestern shore, as well as the south- 

 eastern extremity, is high. Its terraced cliffs rise to about 270 feet 

 immediately back of Cook Point. Tongatabu is irregularly triangular in 

 shape. Its greatest breadth is formed by the southeastern coast, which is 

 about nine miles long. It tapers at the northwestern extremity to a long 

 curved point, Nui Aunofo Point, not more than half a mile in width, which 

 encloses the flats which once formed the northern extremity of Tongatabu, 

 and are now represented only by the islands and flats of Atata, Boloa, Hakau 

 Tabu, Alakibeau, and Tufaka (PL 215). From the highest point of the 

 southwest coast the shore falls very gradually towards the north, and the 

 whole northern part of the island is composed of a comparatively low flat, 

 undulating in places (PI. 116, fig. 1). 



To the east of Nukualofa'" Tongatabu consists of a labyrinth of low 

 islands and islets (PI. 215), which occupy the whole of the straits between 

 Nukuleka and Holevai (PI. 115). The pass between these two points widens 

 out to the south and west into long fingerlike bays, extending the one 

 towards Bea and the other towards Mua, the land between consisting of 

 low swampy ground covered with mangroves ; the whole of that part of 

 Tongatabu forms an irregularly shaped digitate lagoon (PI. 215), which can 

 be navigated only by canoes (PI. 115, fig. 2). 



1 A. Chart 2421. 2 Ibid., 2363. 



