NARRATIVE OF THE CRUISE. 487 



ToNGATABU TO THE Fiji ISLANDS. 



On the 22nd July, at 8 a.m., the Challenger left Tongatabu for the Fiji Islands, 

 passing out to the northward between Mallenoah and Atataa Islands. Nothing was 

 seen of the Juno Shoal, or of any belt of shallow water, the shallowest sounding being 

 9 fathoms. This northern route appeared to be a better channel into and out of the 

 harbour than the eastern, for, although the water is not so deep, the channel is wider. 

 Cook on his first visit used it, but ran on shore two or three times, and left by the east 

 channel, out of which he had to beat against a fresh trade wind. The water appears to have 

 deepened since his time, at any rate the shoals are fairly known, and can be avoided, and 

 no one would now think of working out through the narrow east channel, when he could 

 proceed through the northern with a leading wind. When outside a line joining Mallenoah 

 and Atataa Islands dredgings were obtained, first in 18 fathoms (Station 172), and then 

 in 240 fathoms (Station 172a, see Sheet 28). The deposit at both these depths was a 

 coral mud containing 90 per cent, of carbonate of lime, and composed of fragments of 

 Coral, calcareous Algae, Orbitolites and many other Foraminifera, fragments of Polyzoa, 

 Echinoderms, and Molluscs. At the greater depth farther from the reef, the fragments 

 were smaller and the pelagic shells more abundant than in the depth of 18 fathoms 

 nearer the reef. At 0.30 p.m. the ship proceeded to the westward towards Turtle Island, 

 which was sighted at 11 a.m. on the 23rd. At 2 p.m. on that day the northern extremity 

 of the detached reef off Turtle Island was passed, and a course shaped towards Matuku 

 Island, the weather being rainy and cloudy. 



On the 24th July, at 6 A.M., Matuku Island was sighted, and the vessel having 

 proceeded to the lee side, a party was landed and remained on the island for two or three 

 hours. During this time the ship was engaged in dredging off the mouth of the harbour 

 in 310 and 315 fathoms (Stations 173 and 173a, see Sheet 29). 



The Fiji Islands. 



Matuku Island. — Matuku Island (see fig. 141), one of the Fiji group, lying about 70 

 miles east of Kandavu, is volcanic, and surrounded by a barrier reef which is about 16 miles 

 in circumference. The highest peak is about 1200 feet in height. From its summit the 

 island was seen to consist of a single crater, the edge of which had been denuded and cut 

 into a series of fantastic peaks, with intervening steep-sided gullies. The ancient crater 

 itself now forms the harbour, the inlet to which is through an opening in the girdling 

 reef, at a spot where the border of the crater has been broken down. The surfaces of the 

 irregular hills showed the peculiar sharp-angled ridges so characteristic of volcanic cones 

 denuded by pluvial action. The windward side of the main peak was precipitous, and 



