SMITHSONIAN EXPLORATIONS, I93O 



69 



affairs being looked after by the New Zealand Government under the 

 mandate. 



Niuafoou is one of the world's famous volcanoes. Tt is a crater 

 island 4% by 5 miles in size, inclosing a circular lake about 2 miles in 

 diameter. The narrow circular ridge of land around the lake is 200 to 

 800 feet high, forming steep cliffs facing the lake. The lake has three 

 small wooded islands in it, one of which contains two smaller crater 

 lakes. The island is the peak of a volcano rising 6,500 feet from the 

 ocean floor, which in that vicinity is formed by a Mat shoulder of the 

 Australian continent about 6,000 feet below the surface. Upon this 

 the volcano rises as an immense cone 2S miles in diameter at the base. 



Fig. 60. — General view of the astronomical camp, showing the 63-foot 

 direct view camera, the 65-foot reflecting camera, and the Einstein double 

 camera on the right. (Photograph by Kellers.) 



The known eruptions occurred in 1853, 1886, 1912, and 1929. All 

 started with the splitting of the mountain across its flank except that 

 of 1886. which was in the old crater lake, explosive in type, and mostly 

 of ash, forming sand hills and lagoons. These ash hills are being 

 gradually covered with a dense growth of ironwood trees, the only 

 trees that appear to grow and thrive in the volcanic ash of the island. 



The 1929 eruption was on the western side of the island, the fis- 

 sure system bursting open at 3 a. m., July 25, 1929, near the south- 

 west corner of the island, and extending northward in a series of 

 fissures until it nearly reached the shore at the northwest. The cracks 

 were more than 3^ miles long, requiring several hours in opening the 

 full length of the line of fracture. This delay gave the natives of the 

 village of Futu time to escape to the ridge. The sick and the aged were 



