134 TUTTLE ENGINEERING NOTES ON HAWAII. 



fall is recorded at eighty stations and that more or less complete 

 meteorological observations are being made regularly at 5 points, in 

 addition to the Honolulu station. Besides these records there are a 

 large number of others which are not reported, nearly every ranch 

 and plantation having at least one gauge in use. Kainfall on the 

 islands presents all of the phenomenon usually found on large land 

 surfaces, being low at the coast on the windward side, increasing 

 with the elevation towards the cool high summits in the interior, and 

 diminishing as the lee or southwestern coast is approached. Most of 

 the readings are taken at the lower elevations, which are usually the 

 populated sections, but a few are available for points well up on the 

 slopes, the highest being at 4 000 ft. elevation at Kilauea, Hawaii. 

 The records of normal rainfall show an annual range of from 8.5 ins. 

 at elevation 15 ft. above the sea, at Olowalu, on the leeward side of 

 Maui, to 190 ins. at elevation 1 250 ft. at Kaumana, on the windward 

 slope of Mauna Kea, Hawaii. 



The maximum rainfall record for a year, of which the writer has 

 knowledge, occurred at Nahiku, Maui, and was 400 ins. The dry 

 season of 1901 in Hawaii marked a drought of unusual severity, and 

 was followed in December by a storm which seemed to center at 

 Laupahoehoe, on the north coast, where the precipitation aggregated 

 over 41 ins. during 28 hours, the measuring gauge having been 

 located at 500 ft. elevation; this was a purely local storm, but the 

 one of March, 1902, swept along the entire windward coast of Hawaii, 

 and registered the maximum at elevation 2 000 ft. at Paauilo, where 

 the rainfall for 8 days was 87.91 ins. 



One of the most intense Hawaiian storms of record occurred on 

 March 18th, 1902, at Luakaha, back of Honolulu, elevation 850 ft. ; 

 here the precipitation was 12.7 ins. in 11 hours and 55 minutes, the 

 maximum rate noted having been 5.55 ins. in 55 minutes. 



An analysis of the records along the westerly end of the north 

 coast of Hawaii shows that, during the months, May to October, the 

 rainfall is from 30% to 40% less than in the remaining six months, 

 and that there is an increase in rainfall with increase in elevation 

 above the sea, probably not averaging more than 3.5 ins. per annum 

 per 100 ft. 



Within the limits of Honolulu, records are kept at no less than 

 8 points, located at elevations between 10 ft. and 80 ft. above tide; the 



