384 



DISTRIBUTION OF PLANTS. 



frequently on the high ground of Maui and Hawaii : at such times 

 only, hail falls, and so inseparably, as to be called ' thunder-eggs' by 

 the natives." 



" Twenty miles" at sea under Mauna Kea, I witnessed a limar- 

 hoio, in the evening of the 8th of December during a slight sprinkle 

 of rain ; a nearly continuous semicircle, destitute of the prismatic 

 colors ; and altogether resembling the fog-hows produced by the sun's 

 rays, on the upper portion of Mauna Kea, and along our New England 

 coast, A few nights previously, the prismatic colors made their 

 appearance on a fleecy cloud passing near the moon ; as though pro- 

 duced by the direct transmission of moonlight. 



On the Windward flank of Mauna Kea, at the saw-mill two 

 thousand feet above the sea at Hilo, the evaporation from wet surfsices 

 on the morning of January 9th, was as plainly visible as in cool 

 climates. It is true, where there are no mountains, the warm coun- 

 tries between the Tropics seem to be very generally free from fo<js. 



By a peculiarity perhaps unique, the Hawaiian Islands are subject 

 to LOCAL EARTHQUAKES. These are in some manner connected with 

 volcanic action, for they occur only in the end of the Group that con- 

 tains volcanoes. Two were experienced there by ourselves ; and we 

 ascertained, that these did not extend to Oahu. We learned also, 

 that natives born and brought up in the Western Division of the 

 Group have manifested great astonishment on first experiencing the 

 earthquakes of the Eastern Division. 



Oauu. The Western division commences in the middle of the 

 linear series, with Oahu ; the island we first visited, landing tliere on 

 the 25th of September. Though devoid of a real seat of volcanic 

 action, Oahu has several crown-shaped hills or coast-craters, around 

 its margin, the largest and most remarkable being Diamond Hill, four 

 miles East of Honolulu. On ascending, we found the interior cup 

 half a mile in diameter, with the encircling rim very thin, and a 

 portion of it rugged, wall-like, and inaccessible. The rock, wherever 

 ex[K)sed, on and immediately around Diamond Hill, proved to be 

 cellular lava; rough on the surface, but nowhere presenting the 

 slightest appearances of having issued forth in a lava-stream. All 

 this portion of the island is strewed with blocks of cellular lava; 

 some being even imbedded in the ancient coral-shelf, that adheres in 

 remnants, twenty feet above the water, to the cliffs of the sea-coast. 

 A second coast-crater, similar in form but smaller, is situated imme- 



