676 POPULAR SCIENCE MONTHLY. 



port the cane from the uplands to the mills in flumes. Oahu was 

 neglected because it is comparatively arid. Near Hilo, upon Hawaii, 

 the rainfall amounts to 175 inches annually; in East Maui to 230 

 inches annually; while about Honolulu it varies from 24 to 38 inches; 

 at Ewa and vicinity from 16 to 40 inches, and is quite variable by 

 years, and insufficient for the growth of the cane. At first, attempts 

 were made to supply water by irrigation. Like other cities, Honolulu 

 receives much water from mountain streams brought by pipes for house- 

 hold and manufacturing purposes, as well as for the flowage of ex- 

 tensive tracts of rice land. The great need of water led to suggestions 

 of an artesian supply. In 1879 James Campbell sank the first artesian 

 well upon the island, near the Pearl Eiver lagoon. Water commenced 

 to flow from the depth of 240 feet, and the auger penetrated 33 feet 

 more. The next one was sunk the following year at the mouth of 

 Manoa Valley, where the discharge proved to be abundant from the depth 

 of 298 feet. In the same year Judge McCully obtained a still greater 

 supply from the depth of 418 feet. This last well was within the city 

 limits, where it was easily seen by the public, who thoroughly appre- 

 ciated its value. Many other persons followed the example of these 

 pioneers, till now there are 195 wells upon the five leading plantations, 

 yielding daily 287 million of gallons, and there are many more within 

 the city limits of Honolulu.* 



The Artesian Conditions. 



Oahu presents two series of diversified sheets of rock dipping gently 

 toward the sea from high central points; but the material is volcanic. 

 In the early days successful artesian wells had been sunk through sedi- 

 mentary strata, whence it was inferred that it would be useless to 

 attempt borings in the so-called unstratified rocks. Many were dissuaded 

 from such attempts by that consideration, yet any geologist would 

 quickly observe the resemblance between these volcanic sheets and a 

 nearly horizontal stratification. Nowhere is the succession of varied 

 igneous layers better seen than on Kauai. This land is to be com- 

 pared with either one of the Oahu or Maui domes; so that these latter 

 islands may be termed doublets. The highest land on Kauai is at its 

 center, Mt. Waialeale, over 5,000 feet in altitude. So far as is known 

 no scientific explorer has yet penetrated this central point which is 

 also commonly obscured by clouds. On the flanks of this central 

 elevation are extensive plains gently inclined seaward and reminding 

 one of a sedimentary fan, covered by a fertile soil. Streams have cut 

 through these plains, displaying perhaps 200 feet thickness of alterna- 

 ting volcanic clays, earths or laterites and hard basalts. The diversity 

 of the sheets is such as to give the conditions necessary for the de- 



* Since this statement was made the number of wells and the consequent 

 yield have considerably increased. 



