Mr. Dickinson to Mr. Seward.

No. 143.]

Sir: On the 14th of November last a new volcano broke out in Nicaragua, about eight leagues to the east of the city of Leon, on a crowded line of volcanoes running through the State, parallel with the Pacific coast.

It commenced about 1 o’clock in the morning with a succession of explosions, which were very distinctly felt and heard at Leon. These explosions opened a fissure through the earth’s crust about half a mile in length, running from the old fissure in a southwest direction, about midway between the extinct volcanoes of Las Pilas and Orota, which are two of the numerous cones studding the ancient fissure.

Before daylight on the morning of the 14th fire was seen issuing from the new volcano in various places. The explosions continued irregularly during the whole time that the volcano was in a state of eruption. Sometimes in rapid succession, and other times at intervals of half an hour. Low, rumbling sounds were heard almost incessantly. In the course of a few days two craters were opened on the new fissure, about a thousand feet apart, the one at the southwestern extremity discharging perpendicularly, and the other shooting out towards the northeast at an angle of forty-five degrees. The flames from these two craters steadily increased in size and height, while jets of flame and slighter discharges were emitted from two or three other side fissures.

On the morning of November 22d I went out to the new volcano for the purpose of observing it more closely, though I had seen and heard it very plainly each day and night from Leon. The best view which I obtained of it on that occasion was before daylight, from a mountain summit, about one mile to the northwest of the fissure, and at right angles with it. The main crater at the right was actively at work, throwing out flames and half melted cinders, through a circular orifice about sixty feet in diameter, which was constantly filled to its utmost capacity with the ascending masses. A regular cone, built up entirely by the falling cinders, to the height of about two hundred feet, had already formed around the crater. The rim of the cone was white with heat, and the outside was red hot for half way down, while the remainder of its black ground-work was glittering with innumerable glowing sparks. It was puffing quite regularly about once a second, with a strong constant blast, which kept up a column of flames filled with flying cinders, to the height of about five hundred feet above the mouth of the orifice. Irregular explosions occurred at intervals varying from ten to thirty minutes, increasing the force and volume of the discharges, and sending them far up into the rolling clouds above. The cinders went up in half-fused, blazing masses, from one to three feet in diameter, and came down upon the cone, hardened, striking with a clinking, metallic sound. After daylight the red appearance of the cone changed to a bluish black. The left-hand crater was shooting out oblique discharges of flame and cinders [Page 642]of a similar character, at an angle of forty-five degrees from the other, and evidently communicated with it about a thousand feet below the surface, the two craters being that distance apart, and both discharging simultaneously. This half horizontal crater was about twenty feet in diameter.

The afternoon of the 27th, after a series of explosions which seemed to shake the earth to its center, the volcano commenced discharging vast quantities of black sand and heavier rocks. The column of flame at night was considerably increased in height, and bright, meteor-like spots were seen ascending in the flames, to the height of not less than three thousand feet. These were large, spherical stones, four and five feet in diameter. The next morning the streets and house-tops of Leon were covered with fine black sand from the volcano, and a vast luminous cloud of raining sand overspread the whole surrounding country. This rain of sand continued until the morning of the 30th, when the volcano died away, apparently smothered by its accumulated eruptions. The sand now covers the whole surrounding country, from the volcano to the Pacific, a distance of more than fifty miles from it. At Leon it is from an eighth to a quarter of an inch in depth. As we approach the volcano, it gradually grows deeper and coarser. For a mile around the crater, it lies in particles from three-eighths to half an inch in diameter, and about a foot in depth. Still nearer to the cone, the sand increases to several feet in depth, and the particles gradually increase in size until they become small, broken rocks. Around the base of the cone, round, heavy rocks lie thickly scattered, from four to five feet in diameter; but much the larger portion of them have broken into fragments. The cone itself is two hundred feet high, with a crater in the top two hundred feet in diameter, and about the same in depth. The inside of the crater, the same as the outside, is covered with hard, broken rocks, generally less than a foot in diameter. A long ridge of black scoria leads out from the branch crater, in a northeasterly direction. The slaggy, lavalike scoria which first issued from the main crater, is now principally covered up by the hard plutonic rocks, which came out from profounder depths with the last discharges. The forest for leagues around is scarred and maimed by the sharp cutting storms of sand, and near the volcano the trees lie cut into numerous fragments, half buried under the sand and rocks.

The volcano was an active and interesting sight for sixteen days, and now, in its repose, affords an ample and instructive field for the geologist. Indeed, no country in the world presents a more interesting study than the plain of Leon. Twenty volcanic cones are seen rising from it at a single view. Its soil is inexhaustible in fertility, as finely pulverized and as evenly distributed as that of the valley of the Nile or the Mississippi; not, however, by water, but by fire! It has literally rained down from the volcanoes, richly freighted with fertilizing material.

Humboldt regretted before his death that men of science had not more fully investigated this remarkable region of country, and it is sincerely to be hoped that it may not much longer remain neglected by them.

The recent fall of sand has been followed by a shower of rain; and though but a few days have since elapsed, corn, cotton, and grass have grown more rapidly under its fertilizing influence, than I have ever seen plants grow before. Some weeds and plants it kills, others it starts forth with renewed life and vigor.

I send, herewith, a specimen of the sand gathered at Leon, before the rain, hoping that it may be analyzed.

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It may be proper in this connection to call attention to the recent destructive storms, earthquakes, and eruptions, which occurred on and around the Island of St. Thomas during the same period of time which I have been describing, and which undoubtedly sprung from the same general cause, as those earthquakes were distinctly felt at Leon.

I am, sir, very respectfully, your obedient servant,

A. B. DICKINSON.

Hon. William H. Seward, Secretary of State, Washington, D. C.