192 Transactions. — Geology. 



It will be seen at a glance what an excellent soil the brown 

 gravel in the little specimen-bottle upon the table from Falcon 

 Island (now sunk below sea-level) would decompose into if 

 allowed sufficient time ; so that from this specimen it can be 

 seen how much of the volcanic soil in the Pacific has been 

 formed. I obtained the gravel before the island disappeared. 



There is no water, as I have said, in Tonga except 

 that which is caught in tanks, nor is rain very abundant 

 there, but the night-dews are heavy. The natives bathe in 

 the sea, and use very little water for cooking purposes ; 

 their chief drink being from the cocoanut. Their cooking 

 is done by pouring about a pint of water into a huge earthen 

 pot, closing the neck, and converting the water into steam. 

 Clothes they do without, so that the thirty thousand people 

 there rub along very well without much water. The Euro- 

 peans, of course, use tanks, but the water these tanks con- 

 tain must be a living mass of microbic germs. 



Pylstaart, Kao, Lette, and Tofua are separate small 

 islands to Tongatabu, Hapaai, and Vavau, and tower up, 

 as I have said, from 700 ft. to 3,000 ft. They may have 

 attained these heights by sudden growth, and yet not altered 

 the levels of the three large islands. 



Writing of Savage Island, Mr. Turner says, "It is an 

 uplifted coral island 300 ft. above the level of the sea, about 

 forty miles in circumference, in 19° S. latitude and 170° W. 

 longitude." It will be noticed that Savage Island, the Tongan 

 Group, and the Loyalties, stretching some twelve hundred 

 miles west to east, show an upheaval of 50 ft. to 300 ft. above 

 sea-level. 



The Cook or Hervey Group, over five hundred miles to the 

 eastward, may also be embraced in this line, for wath the 

 exception of Earotonga, which is volcanic and mountainous, 

 the other islands consist of ancient coral formation raised 

 20 ft. to 200 ft. above the sea, some of them low^ er, and all 

 surrounded by living coral reefs. 



Mangaia, the southernmost island of the group, is of coral 

 formation, but otherwise differs from most of the South Sea 

 islands outside this group. It is about 650ft. high, and at 

 a distance appears quite fiat. There is a fringing reef all 

 round, about 2 cable lengths from the shore, and about 

 2 ft. above high-water mark, but with no passage for boats. 

 Boats anchor outside the reef on a ledge, and canoes come off 

 for passengers, &c. The natives then look out for the rise of 

 the swell, land the canoes on the reef, jump out quickly, and 

 drag the canoe to land before the receding sea can sweep it 

 back into deep water. These facts go to prove a late upheaval 

 at Mangaia. 



Yet Earotonga, a hundred miles west by north of Ma- 



