Amphiura Holbölli (Lütken). Ophiopholis aculeata (Lütken), (Ophiolepis scolopendrica, Müll. & Trosch.). Asterophyton eucnemis (Müll. & Trosch.). As before mentioned, Amphiura Holbolli may be Ophiolepis Sundevalli of Johannes Müller; while Stimpson's Asterophyton Agassizii is probably the same as A. eucnemis; and his Ophiolepis ciliata is Ophiura Sarsii. To the above list is to be added a naked Ophiuran with soft skin and long thin arms, probably an Ophioscolex; but no good specimens have yet been obtained. If O. arctica turns out not to be a mere variety, there is still an eleventh species. Finally, Ophiothrix fragilis has been reported from Greenland, and other very cold localities; but this is perhaps more than doubtful. On the Scandinavian coast, from Cape Kullen, in the south of Sweden, opposite the north point of Zealand, to Lofoten, on the northwest coast of Norway, there are found nineteen species of Ophiurans. On the shores of Finmarken (northwest coast of Norway) there are, thus far, six species; and on those of Great Britain, thirteen species. The geographical distribution of the Ophiurans of Greenland is as follows: } Ophiocten Kröveri, Ophiura Sarsii, Greenland and Spitzbergen, limited to the arctic zone. Only in the western Atlantic; at Greenland and Newfoundland. Essentially arctic, though found in the northern temperate sea-belt, as well as at Spitzbergen and the European and American coasts of the polar sea. Ophiopholis aculeata-On both sides of the Atlantic, through the whole arctic and cold temperate zones. O. squamosa has probably the same range. ART. VIII.-On a Visit to the Recent Eruption of Mauna Loa, Hawaii; by Prof. ROBERT C. HASKELL, of Oahu College, Honolulu. (From a letter to one of the Editors). OUR party consisted of Pres. Beckwith, Prof. Alexander, myself and twenty students of the college. Twelve of us went to the source of the flow. Only two persons besides have thus far reached it, though many have visited the stream on the plain between Hualulai, Mauna Kea and Mauna Loa. The eruption broke out on the 23d of January. No earthquake was felt in any part of the Islands at the time, but dead fish were noticed on the 21st and for a few days afterwards, to the east of Molakai and between Molakai and Oahu. The fish gave no evidence of disease, but seemed to have been parboiled. At Honolulu, 200 miles from the eruption, the atmosphere was exceedingly hazy and thick. So much was this the case that it caused considerable excitement, before the news of the eruption arrived. Rev. Mr. Lyons of Waimea states that on Sunday afternoon, Jan. 23d, smoke was seen gathering on Mauna Loa. In the evening, lava spouted up violently near the top of the mountain on the north side, and apparently flowed both towards Hilo and towards the west side of the island. This continued but a few minutes, when at a point considerably farther below the top and farther west, another jet spouted up. Accounts from Hilo say, that on the night of the 23d it was so light there that fine print could be read without difficulty. After the 23d the light was much less. At Lahaina, more than 100 miles distant, the whole heavens in the direction of the eruption were lighted up. Our party started from Honolulu Feb. 1st, and reached Kea lakekua on the 3d. Here we learned that the stream from the eruption had reached the sea on the 31st of January, at Wainanalii, about forty miles from the place of eruption. This makes the average progress of the stream above five miles per day. After procuring guides, natives, pack-oxen and mules we started for the source of the flow on the 5th. About noon we had a view of the source distant probably 25 miles from us in an air line. The crater was about 150 feet high and 250 feet in diameter (as we afterwards estimated). From within this crater, liquid lava was spouting up to the height of 300 or 400 feet above the ⚫ top. In shape and movement it resembled a mighty fountain or jet of water, though more inconstant. At one moment it was uncommonly high and quite narrow at the top, at the next not as high but very broad. At night and from a good position near, the view of the jet, according to Mr. Faudrey (the only man who reached the crater while the jet was spouting) was grand beyond all description. Owing to an accident which befell one of our party, and the failure of water where it was supposed to be abundant, we were delayed two days and induced to divide our party into two divisions. One part returned to visit the flow at a point some twenty miles below by another and easier route. The party who went on, consisting of twelve white persons and thirty kanakas, reached the crater Wednesday evening, Feb. 9, and encamped about two miles from it. Here all fears about water were at an end, for we found snow in abundance within half a mile of our camping-ground. In the evening our view was magnificent. The jet had ceased to play; but two craters, about eighty rods apart, were sending up gas and steam, with appearances of flame. This apparent flame, however, we afterwards ascertained was only fine particles of scoria heated to redness. The noise attending this action was like that of an ascending rocket, very much increased of course, but quite irregular. About half a mile below the lower of the two craters, the stream first made its appearance. For five or six miles its course was well defined, and there were no side-streams. From this point the main stream divided more or less, and on the plain, between the three mountains Hualalai, Kea and Loa, the branches cxtended over a breadth of three or four miles. Some of these streams were very broad and sluggish and partially cooled, some were narrow and running, as it seemed, at the rate of two or three miles per hour, burning the jungle and trees before them and vieing with each other in their work of desolation. For the first few miles the stream appeared to be a series of cataracts and rapids. As it approached the plain between the two mountains, it gradually changed into a net-work of streams, or a lake of fire, embracing numerous islands and sending out streams on all sides. The color of the stream upon its first appearance was a light red approaching to white; on the plain a deep blood-red. From the plain towards Wainanalii the stream was narrow, varying from half a mile to a mile in width, and showing only a dull reddish light. Such was the view spread out before us. To say that it combined the magnificence of a conflagration with the sublimity of a mighty mountain torrent, may give some idea of it; yet such was the extent and variety of the scene that no adequate comparison can be found. The next morning we moved our camp down to the new lava, about half a mile from the lower crater. Here we melted snow, cooked our food, and boiled our coffee over steam cracks. The day proved very foggy and rainy, but we were able to make some explorations about the craters. On the windward side we could ascend them and look in, though the heat was so great that we could look for a moment only, before turning our faces away. The sulphurous gases also were so strong that we were obliged to close our mouths and noses as we approached to look in. The craters were both very irregular in shape, not only on the outside but in the inside. No liquid lava was seen in either at the time. In each there were two or three separate holes where gases and steam were issuing. The sides of these holes and indeed the entire bottom of the craters were at a white heat. The lava stream appeared to be running underneath these craters, and the holes within seemed to be merely vents for the escape of gases. The craters were formed of fragments of light scoria and lava combined. The lower of the two (the one in which the jet was thrown up for fifteen days) was now open on the lower side. This was not the case while the jet was thrown up, according to Mr. Faudrey. It would seem that the force of the jet broke down the lower side, and that after this the jet ceased to play. The upper crater was closed on all sides. Above these two craters we visited a third not then in action, but still hot. This was smaller and open on the lower side, and broken down somewhat on the upper side. This was formed, not so much of scoria as of old lava. Above this we could see others still of the same kind, and it is probable that they extend to the place where the lava first spouted out. From that place to the craters then in action, the stream appears to have flowed under the surface mostly, but to have been forced up to the surface where these craters now inactive appear, by hydraulic pressure, or by the pressure of gases, or by both combined. The next morning we visited the point where the stream first made its appearance. Here we found the lava rushing out from its subterranean passage, and dashing over cataracts and along rapids at such a rate that the eye could scarcely follow it. The lava was at a white heat and apparently as liquid as water. Only a few feet from where the stream issued, small masses of lava were thrown up from ten to fifty feet into the air, which cooled in falling. The cause of this without doubt was the escape of gas, and we then thought that the gas might come from the stream itself. But about three hours afterwards we returned to the same place, and found that the action had greatly increased. Gases were escaping at two other points a few rods below the point first seen. Pieces of lava were thrown as high as 150 feet, and, at the lowest of the three points, there was a fountain some twenty-five feet high. The bits of lava thrown up cooled as they fell, and had already formed craters ten feet high around two of the points where gases were escaping. It was now evident that the escaping gases were not derived from the stream simply, but issued from a vent, which reached to the common reservoir within or under the mountain. We could not remain to watch this incipient crater and fountain, but we were obliged to commence our return. At night, however, from our encampment, about twelve or fifteen miles below, we could see that the crater had increased considerably and also could see the fountain playing a few feet above, but the course of the stream had now changed in part, and half or more of the lava passed down by a new stream. This dashed all our hopes of seeing another large jet of 300 feet in height; and from a friend of mine who visited the spot three or four days afterwards, I learn that the fountain had ceased, and that the crater increased only a few feet after we left. Descending by the stream, we were able to follow it on its south side, as a strong wind was blowing from that direction. Here we found good walking, and could with safety approach within a few feet of the channel. The width of the stream was from 20 to 100 feet, but its velocity almost incredible. Some of our party thought it 100 miles per hour. We could not calculate it in any way, for pieces of cold lava thrown into it would sink and melt almost instantly. The velocity certainly seemed as great as that of a railroad car. For eight or ten miles the stream presented a continued succession of cascades, rapids, curves, and eddies, with an occasional cataract. Some of these were formed by the nature of the ground over which it flowed, some by the new lava itself. The stream had built up its own banks on each side, and had added to the depth of its channel by melting at the bottom. The stream flowed more gracefully than water. In consequence of its immense velocity and imperfect mobility, its surface took the same shape as the ground over which it flowed. It therefore presented not only hollows but ridges. In several places for a few feet the course of the stream was an ascent of five to ten degrees, in one instance of twentyfive. Where the turns in the stream were abrupt, the outside of the stream was much higher than the inside. So much was this the case, that the outside sometimes curved over the inside, forming a spiral. It is needless to add that we were filled with wonder and admiration at the sights we saw. After arriving at the plain between the mountains we had so much fog and rain that we could explore but little. We however saw "pahoihoi" or solid lava forming, and also "aa" or clinkers. "Pahoihoi" was formed mostly by small side streams and always by shallow streams, which flowed freely but slowly. They were derived generally from the overflowing of the main stream. After flowing for some distance they became cooled at the end, and as there was little pressure from behind, gradually stopped. The little ridges which give the "pahoihoi" a ropy appearance, were caused by the flowing on of the stream for a little after it had cooled forward. These are circular because the sides of the stream cool first, while the centre moves on a little farther. These streams become solid in a short time, cooling through, and not simply coating over. At a subsequent time during the same flow, another layer of "pahoihoi" may be formed upon the first, as we saw in several instances. The clinkers are always formed by deep streams, and generally by wide ones, which flow sluggishly, become dammed up in front by the cooling of the lava and in some instances cooled over the top, forming as it were a pond or lake. As the stream augments beneath, the barriers in front and the crust on the surface are broken up, and the pieces are rolled forward and coated over with melted lava which cools and adheres to them more or less. Then, from the force of the melted lava behind and underneath, the stream rolls over and over itself. In this way a bank of clinkers ten to forty feet high, resembling the embankment of a railroad, is formed. Often at the end of the stream no liquid lava can be seen, and the only evidence of motion is the rolling of the jagged rocks of all sizes down the front of the embankment. Sometimes the stream breaks through this embankment and flows on for a time until it gets clogged up again, and then the same processes are repeated. In this latter case the outbursting stream often carries as it were on its back immense masses of clinkers, which look like hills walking. We found no clinkers |