450 ANlSrUAL EEPORT SMITHSOISriAlsr INSTITUnON,, 1917. 



throiiglioiit the jear, though the amount may be greater during the 

 winter. One of the rainiest spots is the simimit of Waialeale, the 

 highest peak of Kauai (5,170 feet), where the rainfall is as much as 

 600 inches. Professor Campbell records the rainfall here as follows : ^ 



1912, 399.35 inches. 



1913, 453.00 inches. 



1914, 610.00 inches. 



1915, 590.00 inclie.s. 



1916, 539.70 inches. 



The chief agricultural industries of the islands are, the production 

 of sugar, the raising of stock, and the growing of pineapples. Sugar 

 cane is grown on the lowlands of Oahu, Kauai, Maui, and Hawaii, 

 where sufficient water is available either from the rainfall or from 

 irrigation. The ranches for stock raising are on the plains and 

 treeless slopes on the leeward sides of the islands, especially on 

 western and northern Hawaii, western Molokai, nearly all of Lanai, 

 and the western part of East Maui. Pineapples are groAvn chiefly 

 on Oahu in localities not well suited to sugar. 



In earlier days horses, cattle, hogs, and goats were introduced and 

 allowed to run wild. Tliey increased rapidly and became a menace 

 to the vegetation. Large areas were almost denuded of native ]3lants 

 and their place has been taken by introduced weeds, especially such 

 shrubs as guava and lantana. In recent years these wild animals 

 have been hunted and killed to such an extent that they are now 

 nearly exterminated, a few flocks of goats being found in the more 

 inaccessible canyons, and small herds of pigs in the upper forests. 

 Much harm to the native vegetation has been done and many species 

 have been greatly restricted in their range, some species being actu- 

 ally exterminated. 



Land that has been denuded by stock is subjected to the danger 

 of further denudation by wind in the drier regions. Wind erosion 

 is especially noticeable on the northern end of Lanai and the north- 

 western part of Molakai. Kahoolawe, a small island not visited by 

 us, is said to have suffered severely from the denuding effects of 

 the strong trade wind. This island lies in the path of the trade 

 wind that blows between the mountain masses on East and West 

 Maui, while the low-lying part of Lanai to the north receives the 

 full force of the wind as it blows between Molokai and West Maui. 



The islands arc of volcanic origin and the rocks arc practically all 

 volcanic. The island mass rises from the ocean floor about 18,000 

 feet below the surface. The great cones of the high jnountains of 

 Hawaii (Mauna Kea, 13,825 feet; Mauna Loa, 13,675 feet) give the 

 unusual difference of level between the summit and base of about 



^ Douglas H. Campbell. An extraordinary rainfall record. Science, n. ser. 46 : 5H. 

 1917. 



