[Extract from letters of John V. Campbell, superintendent of the Arica and Tacua Railroad.] TACUA, November, 1868.

The sight of Arica would fill with dismay any one who had known the place before. The destruction has been complete, and more need not be said, were it not that the ruins and signs of the great devastation that meet one on all sides make the aspect of the place so painful that people who once see it are afraid to look on it again. The lower part of the town is a heap of ruins, except where passages have been cleared to serve as streets, while in the upper part, beyond the reach of the tidal wave, many walls and parts of houses are still standing, but so cracked. and shattered as to be quite uninhabitable, and they evidently show that, even without the aid of the sea, Arica was a mass of ruins after the heavy shock of the earthquake. Further back on the pampa, going toward Arapa, the people have built their wooden sheds in great numbers and with much regularity. It is said this will be the future site of the town.

In the part of the town that was washed by the sea the confusion of the ruins is indescribable, and the effect of the waves is bewildering. Alongside the mole is the stationary engine-boiler of the railway, also the remains of the two locomotive-tenders; up in the market-place is another tender, one of the boilers of the flour-mill, and one of the iron girders of Mr. Hegan's turn-table, all large pieces of iron weighing many tons, that have been carried by the force of the waves more than seven hundred yards. Facing Eusert's house, or rather the site where it stood, is one of the locomotives; farther on, facing Nugent's house, is another; and a few yards farther, the third, all in the sea, broken and completely worthless. The strength of the wave is, however, more apparent at San José, where the piers of the bridge have been cut off, on a level with the bed of the river, and carried in large compact blocks of masonry intact, four, five, and six hundred yards on to the highest ground behind. The tubular girders have been carried a similar distance, and many broken.

The bed of San José River has been filled up about four feet, while our embankment on each side has been washed down, and the temporary track we have built passes over the bed of the river with a culvert of only three feet. This of course the floods will carry away in winter, and how we shall ever manage to construct a permanent bridge I cannot yet

conceive. From San José to near the side track at Chacalluta, fully four miles, the railway track has been torn up and obliterated, the large sand-banks at Chiucoro have disappeared, and an open, level beach remains. The vessel Wateree is on the pampa five hundred yards inland, and about eighty from the highest ground; the America lies in the same line, about two hundred yards nearer the sea; while between them are the shattered remains of the Chañarcillo.

The waves approached nearer the hills than I ever could have thought possible, and the pampa for miles is strewn with wreck. The beach all along is covered with large stones, mixed up with sea-weeds, pieces of wood, of furniture, of machinery, and of boats and vessels; the mixture, which also includes rags, and abundance of papers, custom-house documents, etc., is, however, quite beyond any attempt at description.

Very few people can give a clear account of the catastrophe. Almost all appear to have been paralyzed with fear, and certainly they had good cause. Nugent is almost the only one who appears to have been collected and to have watched the progress of events. He says that when the sea receded, the anchorage of the steamers, which was in seven fathoms (forty-two feet) water, remained dry; that all the vessels were dragged seaward except the Chañarcillo and A. Riviere, which remained aground, and high and dry at their anchorage. Many minutes elapsed, during which the sea appeared to be gathering itself up, until at last it came like an enormous dark green wall, and swallowed up everything it could reach. The wave came over the top of the custom house, which will give some idea of its altitude.

The line to which it reached is forty-five feet nine inches above highwater level, which, added to the forty-two feet that it had receded, will give a wave nearly ninety feet in height. The current was very strong, the log of the Wateree says sixteen miles, and appears to have been circular like a whirlpool. The vessels could do nothing, and were carried about like chips. The A. Riviere was never seen again, but fragments of her wreck were washed ashore. The Chañarcillo, a much stronger vessel, came on shore completely smashed; and from the fact of her having five or six turns of her cables around her hull, we surmise that she must have turned over as many times before her anchor parted. The loss of life so far ascertained is about five hundred and fifty, between the town and the bay. There were some singular escapes. John Williams's wife and children were carried in and out by the waves, of which there were eleven in all, a number of times, and were finally deposited on the high ground. Vacarro, who, having a broken leg, was placed by his friends in a large launch, was carried in and out every time, and was left at last among the ruins of the church of San Francisco. Eusert's horse at the mill was carried off by the waves, and two days afterward was found unhurt on the little island in the middle of the Sisera.

Matters in Arica are still in a bad way, as you may judge for your

self, when I mention that the best-housed man in Arica is Ausdell, who is living in the remains of a first-class railway-car. I stay with him when in Arica.

Tacua had a marvelous escape. Only a few very old houses, these principally at the corners of the streets, where they had no support from other walls, came down. Of course every building suffered; but beyond plaster and paper falling down, and cracks at all the joints, I do not find much damage in any of our property. The dwelling-house stood well, and I have now increased confidence in its strength-a consolation, you may be sure, as we have seldom less than four to six earthquakes daily.

TACUA, September 15, 1869.

Months have appeared years since I last wrote you, so horrid have been the times through which I have passed, and yet I have to be grateful that I and my family are yet alive. I allude to the dreadful visitation of yellow fever, which now, thank God, has passed away.

It commenced in Arica in November, and up to 31st March, 1869, the official records alone show one thousand nine hundred and fifty-nine burials, but the real mortality was over two thousand five hundred. Of our contract-men in the station and workshop seventeen out of twenty died. In July, 1868, I shipped at Liverpool a blacksmith, John Parry, with his wife and three children, and I was in Arica when they reached their destination. First a child died, then the mother, the father followed, and I was taking measures to send home the two orphans, when they died also. The family was thus wiped out completely, and there were many other similar cases.

In Tacua the fever broke out with the suddenness of an explosion and swept to their last rest over three thousand three hundred souls. The mortality would have been much greater, but the people fled to the hills and in that way escaped contagion. Among my wife's relatives we lost, counting grown-up people only, her aunt, and two of her sons, and two cousins. I lost four clerks, and among them our book-keeper and cashier, men we cannot readily replace.

Our situation through March, April, and May was awful; we were expecting death at every moment and continually sorrowing for the loss of one friend after another. At times there were no bakers and no bread, no butchers and no shops. All the apothecaries died and their places had to be taken by amateurs. The carts were insufficient to carry the dead, and three relays of cartmen died in succession. The cemeteries were filled to repletion, and then the bodies were thrown into trenches. We are now walling round these trenches, and they take over seven thousand feet of wall to inclose them.

I have recalled to my memory a time that now appears to me a horrid dream, and I had better turn to a more agreeable subject. You

will now comprehend my long silence, as since the 30th May I have been busy at reorganization, drilling new hands, and pulling up heavy arrears of work.

As you ask me for particulars of earthquakes, I will tell you the result of my long-continued observations. Their course here is invariably from the mountain range to the sea-in this district from east by north to west by south. Walls built north and south-that is, across the course of movement-are those that suffer most. Many have fallen and all are more or less injured. Walls built east and west suffer little if at all, except occasionally when they are at the corner of the street, and then only a few of the last adobes fall.

The movements appear to have the greatest intensity or rather effect in sand. The walls of houses built on sand when they do not fall, as most frequently they do, are left in a crumbled condition, crashed and shattered in every direction. It is clear that the earthquake movement imparts a variety of movements to sand. I think, too, the force that causes the movements acts in the line of least resistance, or tries to liberate itself where it finds its work easiest.

You remember the "big cut" on the A. and T. line and the conglomerate that you so often anathematized. That conglomerate, however, resists earthquakes, and I attribute the preservation of Tacua on the 13th August, 1868, to the town being built on it. Not a stone falls in the big cut, and I have a hole in the yard of my house fifty-one feet deep, all through this formation, with an old wall two feet from its edge, that I was sure would have fallen in, but to my great surprise everything remained sound and intact. This conglomerate is, as you know, very tough and must offer immense resistance to the earthquake force. Our rock here is all trachyte tuffa, a few stages only removed from pumice-stone, and offers little or no resistance to the earthquake shocks. Houses built on it fall easily.

The earthquake waves are low and only measure a few inches in height. The damage they cause appears to me more owing to duration than to altitude of the movement. The earthquake of the 24th ultimo lasted ninety seconds and left things standing; while a duration of five minutes would have brought them down. The effect of this last earthquake on vessels at sea you will find in the Valparaiso papers of last mail in the case of the ship Payta. The water appeared to run away from the vessel's sides, and the people in her feared being submerged. She was fifty-seven miles south of Arica, in a direct line east and west with Islaya, now, as then, in a violent state of eruption, and must have been caught in the very center of the movement.

The effects of an earthquake on a train in motion are worth mentioning. On the 13th of August, 1868, the Presidente (our very first and last engine) took up the train, (regulation load one hundred and twenty tons, cars included, but exclusive of locomotive and tender twenty-two and one-half tons,) and was going at about sixteen miles per hour when

it suddenly stopped with a smart shock. Mr. Ansdell, who was a passenger, thought something had given way on the engine, while Braithwaite, the driver, thought the stoppage was caused from behind. The train, however, would not move, so the steam was shut off and both got down to examine matters. They could hardly stand on the ground, and at once perceived the true state of the case.

Earthquakes are very frequent yet, and the people are in a state of panic, a German astronomer, Falb, having predicted our total destruction on the 30th September or 1st October; while an Englishman, Saxeby, defers the event until the 5th of October. The people are deserting Arica, and the authorities are making us bring up the customhouse to Tacua. On the railway we can barely keep our work going. In Tacua two-thirds of the population are sleeping in tents. I never before witnessed such a fright. People refuse to transact business until after the 5th of October, or when purchases are made delivery is stipulated for after that date.

Several shocks, and two very severe ones on the 20th and 24th of August, have enforced the German's predictions, and it is becoming heresy to argue against him. The Cordillera is to be the shore of the Pacific.

The anniversary of the 13th August was a great day in Arica. There were masses and religious processions to prevent a repetition of the great cataclysm, but the people were very anxious, and passed the day on the hill-tops, relieving themselves at intervals by prayer and flying visits to the taverns. All, however, passed off well.

THE ELECTRO-MAGNETIC SEISMOGRAPH.

BY PROF. PALMIERI, OF THE UNIVERSITY OF NAPLES.

[Translated by B. O. Duncan, esq., United States consul, and furnished to the Smithsonun Institution by the Department of State.]

In all the instruments invented up to the present time for registering the movement of the earth's surface, the force itself of the motion of the earth has been charged with the labor necessary for preserving the trace of the shocks; and this is the reason why slight oscillations of the soil could not be registered. In the seismograph, which I am about to describe, it is the electric current which performs the labor, and, therefore, it is possible to have a registering apparatus capable of the greatest precision even for the slightest shocks. It is also possible by means of this apparatus to perceive the register of many vibrations of the earth which would otherwise escape observation.

Suspended above a small iron cup containing mercury is a fine brass wire coiled into the form of a cork-screw, of about fourteen or fifteen turns.