J. D. DANA'S VISIT.
Mr. Dana was one of the scientific corps of the Exploring Ex pedition. It seems very strange that the geologist of the expedi tion was not directed to explore the volcanoes. The commander evidently wished to save that bit of work for himself ; and it must have been a source of satisfaction to Dana that he was able to correct the errors of Wilkes' map, even though it necessitated a visit to Kilauea in 1887, forty-six years later. The official report upon the Geology of the Expedition was published in 1849.
Dana first saw the volcano in November, 1840, two months before Wilkes went there, and six months after the eruption. He spent five days in traveling from Kealakekua to Hilo, two nights and a day at Kilauea. The great lake, I,5oo feet long and 1,000 wide, was then in full ebullition over its surface, and there were two smaller lakes. Everything was quiet. "Instead of a sea of molten lava 'rolling to and fro its fiery surge and flaming bil lows,' the only signs of action were in three spots of a blood-red color which were in feeble but constant agitation, like that of a caldron in ebullition. Fiery jets were playing over the surface of the three lakes ; but it was merely quiet boiling, far not a whis per was heard from the depths. And in harmony with the still ness of the scene, white vapors rose in fleecy wreaths from the pools into a broad canopy of clouds not unlike the snowy heaps that lie near the horizon on a clear day, though changing rapidly in shape through constant accessions of cloud material from be low. When on the verge of the lower pit, a half-smothered, gurgling sound was all that could be heard. Occasionally a re port like musketry came from the depths ; then all was still again, except the stifled mutterings of the boiling lakes." In the night the surface sparkled all over with shifting points of dazzling light like a "net work of lightning." The smaller pools on the southeast side tossed up jets much like the larger, even to the height of forty or fifty feet. Streams of lava, a day later, boiled over from the lake. Upon the black ledge there
were streams of hardened lava, some twisted into ropy lines or reaching out in rounded knobs, which testified to the presence of lava-floods much earlier than the recent eruption. Among the chasms he heard a few long-continued rumbling sounds, show ing that a down plunging of the walls was still in progress.
The shining, glassy scoriaceous crust crushed under foot is the scum or frothy part of the boiling lakes. The Pele's hair was spun from the jets of liquid lava thrown up by the boiling process. The winds carried away the capillary threads, the heavy or loaded end going down first. The first view entertained was that the wind drew out the glassy hairs ; but it was shown later by Dutton that the threads are drawn out earlier. The projected lava is divided into a succession of clots, the hairs are spun as the pieces pull apart and the wind later transports them.
Dana at this visit recognized the growth of cones from the solidification of lava about the edges of the pools. To the east of the lakes there stood a singular sphere of lava like a petrified fountain. "A column of hardened lava drops had been raised on a rudely shaped conical base, having a height in all of about forty feet. It had been formed over a small vent, out of which the liquid rock was shot up in driblets and small jets—making one of the fantastic driblet cones, as the author has since called them—the result of blowing-hole action." These are spiracles as defined by Scrope.
The surface of the great lake was bordered by banks fifteen to twenty feet high. Dana got the impression of a very quiet action. It seemed as if a copious stream came to the surface for a mo ment and then flowed on. Combined with this the natural opposi tion to the statements of what seemed exaggerated tales of vio lence, led him to deny to a large extent the presence of explosive action. Kilauea was the type of quiet volcanic action. Ex plosive action pertained to other volcanoes like Vesuvius.