My experiments with volcanoes

Whereas small scale experiments in the laboratory helped me to think about the details of nature’s experiments, there remained the need to measure nature itself. The deep lavas of South Dakota, squeezing among shale beds, posed many questions. What penetrating of strata goes on under Vesuvius? Does lava inrush tilt or lift the ground? Does this measure up to eruptions in or from craters? Cannot experiments with craters themselves be made by dwelling there? Certainly the progress of lavas can be measured as they flow forth.

The decade following my mud-pie experiments saw me assistant professor at Harvard and head professor of the geological department at Massachusetts Institute of Technology. These appointments were under Presidents Eliot, Pritchett, and Maclaurin. From 1901 to 1910 I continued to serve the Geological Survey, writing up back reports. Then nature took a hand. Along came earthquakes and eruptions in Guatemala, a terrific disaster in the West Indies, expeditions to the Caribbees, Italy, the Aleutian Islands, Japan, Hawaii, and Central America, another in north Japan, and disastrous earthquakes at San Francisco, Valparaiso, Messina, and Costa Rica. The destruction of St. Pierre in Martinique set the stage for field work on volcanoes and earthquakes, work which I was to continue for a half century.

When the evening papers of May 8, 1902, announced the sudden annihilation of 26,000 people that morning at 8 o’clock at St. Pierre, Martinique, I went immediately to President Eliot. Knowing that I had been urging field study of volcanoes, he agreed that I ought to go to St. Pierre and wired Secretary of the Navy, William H. Moody, to arrange for transportation. Immediate financial support came to me from Alexander Agassiz, the National Geographic Society, and numerous friends; and my Harvard colleagues agreed to give my lectures.

I reported to the training ship Dixie in Brooklyn, where I found Captain Robert Berry, a stalwart Virginian, in command of a cadet crew. On board were I. C. Russell of Michigan, author of “Volcanoes of North America”; E. O. Hovey of the American Museum; Curtis, the maker of topographic models; R. T. Hill of the Geological Survey, and expert on Caribbean lands; and numerous other scientists, and newspaper correspondents.

The voyage to the West Indies was unique. On the navy cruiser were stores of food, tents, clothing, and medical supplies for the refugees and an oddly assorted passenger list; all assembled because of warfare against mankind by two utterly unknown volcanoes, Soufrière on the British island of St. Vincent, and Pelée at the north end of the French colony of Martinique. Geologists gave lectures to the crew on deck; and in turn, we learned about naval discipline and efficiency.

When we arrived at Fort de France, thirteen days after the terrific disaster, we were transported at once to St. Pierre on the naval tug Potomac. We landed and walked through the ruined sugar city, the streets puddled with molasses and rum. Thousands of dead were buried underfoot amid the rubble, for the day before our visit, there had been a second blast from Pelée, the 4,000 foot volcano smoking four miles away. This had thrown down what roofs remained after the first explosion.

We arrived opposite St. Pierre May 21, 1902, and saw a smoking, dusty line of ruins along the shore. Before we landed we were warned that if the tug’s whistle should blow we were to make for the boats. The dusty hill lay on our left like a gray snow landscape, not at all like a cone. The crater was a gorge in an ordinary mountain under clouds.

We wandered through the dreary ruin and found masonry completely destroyed and no visible large volcanic fragments. The streets were full of rubble, and everything was coated with green-gray powder. Roofs were gone, an occasional timber was burning, and bodies were still numerous in the shells of houses. We saw a baby in an iron cradle, a man face down in a tank, and a big man on his back in a deep baker’s oven. His flesh was shriveled and drawn away from his joints by heat. Elsewhere eight or ten bodies were crowded at the foot of a cliff.

The end of the town toward the volcano, all backed by cliffs, was deeply buried under gravel, but the southern end had a covering of only a foot or two of sand. The second explosion was greater than the first one, demolishing third storeys and the second belfry of the cathedral. The beautiful bells “whose soft liquid notes used to ring across the bay with touching cadence at the Angelus hour” lay tumbled in rubbish, splinters, and steaming vapors; their ancient embossed inscriptions half buried in dust.

The bodies were mostly shriveled to a crisp from the second eruption, for earlier the bodies had not been much altered. The odor was a haunting one that returned in dreams—of foundry, steam, sulfur matches, and burnt stuff, and every now and then a whiff of roast, decayed flesh that was horrible. It was impossible to realize that this Pompeii had been a thriving French town two weeks before. Not a roof was left, and scarcely a timber; steam came through little holes in the wet brown sand, and a sickening whiff showed whence it came.

It was hard to distinguish where streets had been. Everything was buried under fallen walls of cobblestone and pink plaster and tiles, including 20,000 bodies. A New England town would have blown away as white ashes before the giant blowpipe acting on the flame of burning rum.

I looked toward the gray old volcano, with shrouded summit. The landscape was dusty, like old statuary. Mountain slope and cliff were denuded of trees. An overturned factory boiler had holes punctured by flying stones. A circular marble fountain basin was chipped away on the volcano side by bombardment. Old cannon used as mooring posts at the quay had been uprooted violently. The green landscape ended abruptly at the city along a sharp line, with coconut palms half green, half brown. There was no motion except steam jets on Pelée’s slopes.

Suddenly I wondered what those steam vents were doing. At first there had been one or two along the sea front; but now there were eight, ten, twenty, spurting high and scattered all over the volcano. A physician, Dr. Church, was standing near me, and we agreed that we disliked the outlook. Now there were forty jets, like so many ghostly locomotives run out from the Pelée roundhouse. Meanwhile, white-coated officers and scientists were scattered about in groups under the cliffs, some out of sight of Mount Pelée.

We looked toward the USS Potomac; she had seen the steam, and her own white steam presaged quick, repeated toots of her fog horn. Pellmell the passengers came tumbling to the landing. The sailors had no sooner started the boats than two more white-coated figures appeared, and we had to put back for them. The mountain looked as though it were rifting in a hundred places preparatory to an outburst, and there were many stories of new craters forming. What we saw was actually the product of a smart rain shower, falling on red hot dry gravel; but we were to learn later about rain rill explosion. Wherever a stream rill runs down to such contact, a jet of steam forms at once.

The main water gorge of the Pelée crater was blown clear of clouds as we steamed past, and we saw a cup under the summit amphitheater where a lake had been, with a pile of scaly looking hot boulders in its midst steaming violently. This crater extended into a deep gulch to the ocean, whence had come a disastrous mud flood on May 5 which buried a sugar mill. This had happened three days before the destruction of St. Pierre. Water preceded steam. The cracks under the gulch undoubtedly dipped away from the city, and from an unknown chasm athwart the gulch line ejected water and superheated steam toward the city, like a jet from a hose. This happened on May 8. The ejected material had been in dry steam, and red hot, accounting for early reports of lava at night.

I saw molten rock five weeks after the Potomac trip, when the crater cone was above the rim of the gorge, apparently large fragments of brown angular material resting on finer gravel. Cauliflower clouds of reddish dust spurted up the bed of the gulch below every half hour, and migrated down the gulch. This was followed by a low growl, perhaps from avalanches. The basin widened during the month, and the dome gained in height and breadth. A bright incandescent crack at night was seen to cross the heap obliquely. A sudden increase of glow was followed by a rumbling, as though the dome were heaving. Breadcrust bombs of andesite, cracked on their surface in deep gashes, and picked up on the mountain at both Pelée and Soufrière were pieces of the internal lava.

A chance clearing of the whole dome came two months after the obliteration of St. Pierre. This we photographed, when brown dust was rising, and steam jets appeared southeast on the dome and in the gulch. On top was an extraordinary spine, shaped like a shark fin, with steep escarpment to the east, curved and smooth and scraped to the west, pushed up and out of a central rupture of the dome. It was like paste from a tube, a hard central pencil of lava that had been shoved up by the expansive force within. Jagged surfaces of breaking showed on the vertical east cliff and long, smooth, arched striations of scrape appeared on the rounded west profile of the protuberance. Other hornlike projections showed on the dome. The summit spine was 200 feet above the surface of the heap.

On July 6, 1902, came the first report of the famous Pelée spine. It crumbled in August, and a year later a new spine, facing in the opposite direction, reached a height of 1,000 feet. It was a central tongue of the semisolid lava of the dome, sufficiently plastic to be urged out by forces within. Otherwise the dome was a nearly solid extrusion covered with fallen bombs. This was the magma, or lava, of the Pelée-Soufrière eruptions. Dike ribs extended radially from the spine athwart the dome. I published an erroneous explanation that the dome of boulders consisted of old fragments melted by a superblast and was not true lava. I was so far right, however, as to anticipate the gas-heat theory and melting of all volcanism.

The direct crisis of these Carib islands in 1902 was introduced by Soufrière Volcano on St. Vincent, 100 miles south of Martinique, at 1 p.m. on May 7, nineteen hours before the St. Pierre disaster. Soufrière exploded, as the common saying is, through a crater lake pit southwest of its 4,000-foot summit, the crater edge being 3,500 feet high. It is notable how many volcanoes are 4,000 feet high, and how many have crater pits, not at the top, but along a rift below the peak. Just this was the case of Pelée, just this characterizes the calderas of Kilauea and Mauna Loa. A dozen other volcanoes could be named where the vents are through the flank of the heap.

Hovey, Curtis, and I were taken by the Dixie to St. Vincent, where the hospitable English colonists provided us with houses at the base of Soufrière, and with servants and horses; and the Government supply steamer took us around the island. We made the ascent of Soufrière to the edge of the great crater and looked down at boiling waters far below, green and muddy, and sending up a column of steam on one wall.

We three Americans guided by T. M. MacDonald, a Scottish planter, made the first ascent after the fearful eruptions of May 7 and 18. Leaving our quarters at Chateau Belair, we climbed on foot from the southwest base, with six stalwart negroes carrying instruments, water, and food. In the ruins of Wallibu sugar mill we encountered a wild-eyed East Indian coolie and his helpers looting sugar.

The Wallibu River received the brunt of the heavy, dry, red hot, gravel of the eruptions, drifted like snow and crusted with wet mud. Water supplied by the river broke its way into the eighty feet of incandescent fill of the valley. Instantly a steam explosion was hurled up in white volutes, and the river dammed its own channel with the stone shower from upblasts. This forced its own waters into fresh hot cinder and so maintained explosive action. One such exploding river sent up a column three quarters of a mile high, indescribably majestic, causing the natives to report new craters. A shower of mud and sand fell on our party.

The old road crossing Soufrière mountain was destroyed, the river flats were deeply trenched, and difficult ridges and hollows were encountered at every step. The gulches were deepened into gorges, the slopes above furrowed with a feathery rill drainage pattern. Each spur between gulches was like a very steep roof, with a smooth pathway uphill along the watershed. This made progress easier. Big tree stumps of Ficus jutted ragged through the hardened mud, the branches charred and sharpened by sand blast.

A whirl of volcanic sand made an unpleasant stinging shower of dust, and sulfuretted hydrogen smelled of rotten eggs. But near the summit the air was fresh and the sunshine bright. A rain would have made the mud slippery and perilous, for the gulch slopes were practically cliffs. Finally we did come to mud clots, resembling a cattle wallow, knee deep and sticky. Large blocks of rock two feet across lay on the surface, flung-out pieces of the old crater walls; and there were some bombs of new lava.

After three hours we assembled at the rim of the old crater, which before the outbreak had been full of a high crater lake. Suddenly we came to an immense chasm almost circular, then the profile of a black precipice falling away 2,000 feet; and up its face we saw a silent steam column purling away in billows. The bottom was a green pool of boiling water, muddied by springs from the wall; and a hundred tails of white steam joined the column on the wall.

The inner walls showed horizontal bands of old lava, and intrusions both in lens shape and as dikes. There were red brown puddingstones made up of fragments. A funnel-shaped intrusion looked like the diagram cross section of a volcano, making a perfect T of gray lava, like a mushroom. A large fissure, filling west, rose from bottom to top. A northern rocky horseshoe rim, or somma, at the top made the peak of St. Vincent. The crater lip was a mile wide and the interior a half mile deep; and the green puddle at the bottom was 1,200 feet across. The base of the wall column sputtered fiercely and sent up spurts of black mud and rock fragments. The lake level was 1,100 feet above the ocean, 800 feet lower than before the eruption; and the pool was shallow, with mud flats and islets. We operated cameras, compass, and sketch books; paced off a base line; and noted that the northwest corner of the crater had been blown away to leave a big notch.

When we returned to Chateau Belair, the negro peasant women brought out their children to gaze at us, the godlike men who had dared the crater. Mr. MacDonald had to steer us through the crowd, and we felt like the twelve apostles after a miracle.

The Soufrière eruption during the first week of May was more voluminous and violent than that of Pelée, for Pelée was concentrated on one target. Soufrière wrought havoc east and west, whereas Pelée was in a sector southwest of the mountain. They were equally devastating, however, and both made downblasts of superheated steam and gravels. Scalding dust killed people, but so did water waves, conflagration, steam, stones, drowning, and burial.

Soufrière’s dust fall was reported all the way to Trinidad and Barbados; and from ships east and southeast, directly against the trade winds, from 100 to 900 miles away. The dust column penetrated the antitrades of the upper atmosphere. Sounds were loud 150 miles away, but not heard close to the mountains. In the red hot gravel were innumerable landslides, river waters rushed into the gravel and made false eruptions, and shore cliffs collapsed.

No lava, except as fragments, appeared in St. Vincent, whereas it rose as a crateral heap in Pelée. Floods of rivers radial to the volcanoes appeared both before and after the first eruptions, and scientists erroneously attributed them to cloudburst rains. Later, exact descriptions by natives showed that the sources were hot waters gushing out in places where there was no rain.

A succession of eruptions at increasing intervals from May to December actuated both volcanoes. In succeeding years, explosions dwindled; but over Pelée’s crater rose a mighty dome and spine of stiff quartz-basalt lava, like ointment from a tube.

There was, on Pelée, a splitting of the bottom of the long crater gulch. Cauliflower steam volutes charged with dust gushed up the cracks, hard-edged in profile down near the shore, soft and diffuse near the crater. Scalding waters in the gulch bottom carried mud. The mountain was cracking open along radial gulches, and squirting up steam and geysers, but this all concealed itself with sediment. Nobody ever saw the cracks open. The migrating steam clouds charged with gravel were called glow clouds and were believed to “flow” as gas fluids from the crater.

An elucidation of all this mystery came many years later, after a thorough study of all reports. The glow clouds, which were at first confused with the gigantic blasts that had destroyed the city, were gradually explained. It became apparent that radial cracks are ancient characters of lava domes, and that lava domes lie under heaps of agglomerate. Pelée and Soufrière are heaps of agglomerate. Kilauea and Mauna Loa are lava domes. Vesuvius is an intermediate type of volcano.

I remained in the field from May to July, returned to Mount Pelée, cruised through the northern Caribbee Islands, and went to the bottom of the deep crater of Mount Misery, on St. Kitts. My guides on St. Kitts were two colored men, Johnny Eddy and Samuel Jim. In the crater we found steam and sulfur and a rotten-egg smell, on the bank of a cold crater lake. We descended by seemingly vertical cliffs covered with roots. This was a typical fumarole, or solfatara, one of the unsatisfactory characteristics of craters. We collected specimens and took snapshots, wondered how often such places change suddenly, and knew hydrogen sulfide gas only by the smell. It all jibed with what I was later to discover in Hawaii; that the only way to know a crater is to live with it, and that gases can melt lava.

As I look back on the Martinique expedition, I know what a crucial point in my life it was and that it was the human contacts, not field adventures, which inspired me. Gradually I realized that the killing of thousands of persons by subterranean machinery totally unknown to geologists and then unexplainable was worthy of a life work.

The story of Rita Stokes made a tremendous impression on me. In Barbados hospital I talked with this young white girl and her colored nurse, Clara King, who had been passengers on the SS Roraima which was at St. Pierre when the city was destroyed. When I saw them they were swathed in bandages. Clara’s burns were severe on knee, arm, and hand. Rita’s were on her head, hands, and arms, and one seriously disfigured ear. Both were somewhat injured for life. Mrs. Stokes, a boy, and a baby girl in the cabin with them had been killed. All saw the adjacent mountain sending up puffs, as the ship lay at anchor off the St. Pierre waterfront on the morning of May 8, but they were reassured by the ship’s officers.

Suddenly the steward rushed by shouting, “Close the cabin door, the volcano is coming!” Mrs. Stokes slammed the door just before a terrific explosion came which nearly burst the ear drums. The vessel was lifted high and sank down, and all were thrown off their feet by the shock, and huddled crouching in one corner of the little cabin. Scalding moist ashes poured in through a broken skylight in inky darkness. Next came suffocation, relieved by the door bursting open and air rushing in.

When a little daylight came back, Mrs. Stokes and the little boy were plastered black with hot mud, the baby girl was dying, and the nurse and Rita were in great agony. A heap of scorching mud had collected on one corner of the floor, and as the young girl put her hand down to raise herself, her arm plunged to the elbow in scalding sand. They were all taken out to the deck where mother, boy, and baby died. The ship was on fire, and the nearby city was a mass of roaring flames. More ashes fell and scalded the victims. Curiously, third degree burns were left on flesh, through underclothing not burned at all.

Clara said that the mountain appeared gray with smoke rolling west, that the weather was very calm, and that the dust smelled like gunpowder. She saw no flames during the blast and did not know what set fire to the steamer. The fires probably came from the city. Ashes came in sputtering splashes like “moist marl.” No rocks fell and the grit in cabin and on burns was wet sand. Before the blast there had been falling dust but, according to Clara, no difficulty in breathing. The sun was brownish red.

The bow of the ship was pointed seaward, and the vessel heeled over left, then right. The stern, toward the conflagration, caught fire first, the bow later. There was no rumbling, only shock and rattling thunder all at once, no noise before or after. The only people Clara King saw toward the shore were some men on a raft.

I wrote President Eliot and the American Relief Committee about the case of Rita Stokes, half American and the only white woman saved in St. Pierre. And I rejoiced to learn from her guardian and uncle, J. E. Croney of Barbados, that she was provided for. The sum of $450 was sent to the committee, and $6,000 in trust was set aside for her. She was never separated from her devoted nurse, Clara King.

Apart from the experiences of the wounded, I found much to contemplate in the findings of numerous geologists; in the accounts of doctors, sailors, naval officers, resident government men, the local newspapers, and photographers; in the specimens we collected; and in the work of great newspaper and magazine correspondents.

The facts and photographs we collected were baffling. They did not correspond with the text books. Two volcanoes a hundred miles apart suddenly spouted death downward. Obviously they were connected along the island chain, with ocean to the east and ocean to the west. Telegraph cables were broken. Why? That which lay under the ocean was totally unknown, both events and topography. The biggest part of these volcanoes was submarine.

Earthquakes at Pelée were relatively small but often continuous. Tidal waves were local and accompanied by downblasts of steam. The downblasts were at first supposed to be due to fallen avalanches from the upblasts. Then it appeared they were really sloping jets from concealed holes or cracks in the gulches, with inclined orifices amid the blocks of a cracked-up mountain. For at Pelée the blast that destroyed St. Pierre shot from the crater gulch in cascades of water and steam, while observers on high ground saw the horizon, or clear sky, over the crater.

The speed of the blast was six miles in two minutes, or 180 miles per hour. This was different from the glow clouds in the later months, migrating slowly along cracks in the gulch bottom.

Man’s perception of speed relative to himself has nothing to do with actual speeds. It may be argued that a miniature volcano erupts faster than a big volcanic system, but not if the whole terrestrial plexus of systems is taken into account. An eruption of Mauna Loa is a very slow affair, in comparison with the 10,000 underground squirtings of lava in cracks totally unperceived, except as tremors on seismograph.

Pelée’s eruption was like turning on a hose. A structural valve or orifice, suddenly opened by underground heaving of the mountain block and letting out steam and mud, appears to be the only reasonable explanation of what happened. And the only agents possible were glowing stiff lava heating boiling water underground. Both of these were later identified.

Grove Karl Gilbert of the U.S. Geological Survey, who had criticized favorably my manuscript on the Black Hills intrusive lavas, wrote me not to drop the enigma of Mount Pelée, because he found the published reports unsatisfying. In 1949, forty-seven years after the disaster, I published “Steam blast eruptions,” dealing with Pelée. In the interim I studied many volcanoes.

Alexander Agassiz, who had been urging me to do a memoir on volcanoes, financed a trip to Vesuvius when it exploded and poured out lava in 1906. Ottajano northeast of Vesuvius was demolished by jets of gravel and stones; and Boscotrecase at the south was invaded by black streams of heavy, sprouting, bouldery slag. Here was a change of habit, from heaping up lavas for thirty-four years, to collapse, internal avalanching, and pure steam explosion accompanied by remnants of stirred lava flow.

Why thirty-four years? A third of a century? Three times the sunspot interval? The previous steamblast explosion of Vesuvius before 1906 had been in 1872. In the case of Mount Pelée and Soufrière the intervals since past explosions had been fifty-one years and ninety years. But it should be pointed out that the Carib volcanoes had two years of terrifying rumblings, odors, and quakes just before 1902. Groundwater exists in large volume under all three volcanoes. Soufrière, Pelée and Vesuvius all began the steamblasts with collapsing craters, that is, with internal lava going down into the bowels of the earth. The lava usually showed in Vesuvius, whereas at Pelée and Soufrière it merely made fumaroles, or gas vents. Man, a mere microbe, could make nothing of hot sulfurous cracks.

On April 25 the electric train slowly pushed us up as far as the observatory station, beyond which all was destroyed. Outside Naples the fields were covered with two inches of gray-green dust, and pines and palms were loaded with a two or three foot drift of sand. Near the observatory a heavy six-inch mantle of sand and dust buried the lava fields. The Vesuvian cone was covered with straight sand slides, whitish gray, which occasionally slipped downward. The landscape was shrouded in drifts of white ashes revealing obscurely the slaggy contortions of lava beneath. Pure white steam boiled up from the cavity in the peak, surrounded by an older rain cloud, like a hat on the volcano’s crown.

My companions—Dr. Tempest Anderson and Messrs. Yeld and Brigg—were all from Yorkshire. We started the ascent of the twenty-nine degree slope in a strong west wind. The steam settled down on the summit, than alternated with clear spells. We followed the west profile of the cone straight up, noting how the funicular rails were twisted by landslides. Everything was covered with pebbles, sand, and dust, with here and there large fragments up to five feet across. We found solid footing on the radial elevations of either scoured old lava or packed fragments. The gullies were filled with deep sand.

The rim we could see ahead was the edge of the crater itself. The abruptness of the fall off, when we finally came to it, was startling in the extreme. The wind was pelting our necks with stinging sand grains which, incidentally, were ruinous to my new Kodak. Only occasionally did sunshine sift through the mixture of sand, steam, and cloud. We could make out an inward slope of thirty-five degrees, terminated 100 feet below by a jutting, fuming precipice. The circular curvature of the crater was embayed. The only noise was the howling wind. We could not see the opposite side of the collapsed cauldron a half mile across. The summit was 4,000 feet above sea level by aneroid measure, 350 feet lower than before the eruption. There was a great notch northeast toward Ottajano where thousands of tons of gravel were hurled clear over the top of Monte Somma, the encircling old ridge. The east-west diameter was left much greater than that of the north-south. The radial ridges and gullies were like a corrugated roof, and sand made a flattened angle of scree at the base of the scoured cone. The corrugations were not rain erosion, but were made by backfallen debris sliding. I got some photographs and Mr. Perret gave me others.

The big thing was the line of mountain blocks of earth crust. In Italy it is made up of Ischia, Pozzuoli, Vesuvius, Lipari, and Etna, whereas the Carribbee line is made up of Mount Misery, Montserrat, Guadeloupe, Dominica, Martinique, and St. Vincent. Such a line of broken earth blocks is a volcanic system. Hundreds of miles long, it is never quiet. A single place seems quiet because superficially we are totally unconscious of the other places. A microbe on the scalp knows nothing of the skin of the toes. Men are mere microbes on the skin of shore, sea, and island. And they are remote from any consciousness of sea bottom.

Vast distances and long intervals are writing records, but man does not measure them. He measures civilization, wars, and dynasties, not the adventures of the ground he dwells upon. Ground he considers static. Actually it is intensely dynamic. Occasionally it explodes and man is destroyed. Earth history and volcanic systems make wars look very small.

The tremendous accumulations of broken rocks over lava beds on the cone of Vesuvius, and on all the Caribbee Islands, recall the breccias, or volcanic conglomerates, of the Yellowstone and of the High Plateaus of Utah. Floods of basalt alternate with vast falls or outwashes of volcanic gravel. Avalanches, landslides, torrents, floods—call them what you will—cover immense areas of the Cordillera. Vesuvius and Pelée pile up cones, but the Caribbees and Italy are also heaped with agglomerates. Erosion destroys cones, but erosion makes agglomerations or valley fills of rocks and mud. This is the history of every volcanic system on the globe. Stübel discovered smooth basalt domes like Mauna Loa under every volcanic system.

In 1904 Vesuvius had vented a lava flow which stopped in September, and its cone was sharp, with only a little crater and inner conelet on top. In 1905 lava had flowed from a northwest split. On April 4, 1906, a splendid black cauliflower cloud arose. The northwest flow stopped and a southern radial rift made lava mouths progress 500, 1,800, and 2,400 feet below the top, more than halfway down the mountain. From the lower mouth came glassy pahoehoe, or smooth destructive streams intensely incandescent and liquid, quickly cooling to aa, or sprouting rough fudge, black crusts, and clinker. The molten porridge flowed as a snaky avalanche into the masonry village of Boscotrecase.

On April 7, at the crater, a column of boulder-laden steam shot up four miles, snapping with lightning. New lava mouths sent forking snakes crushing and swallowing parts of the village. A graveyard was neatly filled within its masonry wall, showing that internally the rocky torrent was a liquid.

Meantime trajectories like those of a hose sent falls of gravel for miles, to Ottajano on the opposite side of the mountain. These also came from the central crater. On the west flank, at the observatory, the house was rocking, and heavy stones forced its occupants to retreat. Matteucci and his staff went halfway down the cone, to return next day. Explosions dwindled during the next fortnight, though one day an adverse wind from the crater carried carbon dioxide and hydrogen sulfide almost asphyxiating some persons. Thereafter cauliflower clouds of white steam arose and the noise of big avalanches was heard.

The clinker field that invaded Boscatrecase was 16 feet thick, and houses were cut in two by a slaggy torrent. In Ottajano, on the opposite side of the mountain, flat tile roofs collapsed, buried under three feet of heavy gravel, some of it the size of an apple. Nearer the crater, boulders five feet in diameter were thrown a mile. The volcano was probably blocked inside by welling lava on the Boscotrecase side, which caused it to vomit steam and earthy avalanche material obliquely outward on the opposite, Ottajano, side.

The Italians have a word, sprofondimento, which means to make profound by insucking, that expresses what happened. This plexus of uprush of slag and inrush of avalanche, against a water-steam geyser, both happening at once, was very different from the quiet outpouring of lava during the preceding years. It definitely meant rupture of earth blocks, deep escape of that lava probably at the underocean part of the radial cracks, and deep entrance of spring water into incandescent vacated chambers. It meant a rupture crisis, collapsing the peak, and a new geyser quite unrecognized. The eruption ended when the slag pressure was relieved, the mountain blocks had settled, and the frozen slag had shut off groundwater. The remaining lava entered into decades of deep accumulation and gas bubbling, the solfataric phase. That which ended the thirty-year upbuilding was probably downward pressure due to weight of surface heaping of the cone. Cracking released water inward.

The next thirty-eight years were to culminate in a similar crisis for Vesuvius which lasted ten days, and again its peak collapsed. This was in March 1944, when our American troops entered Naples. It is interesting that these culminations have been from a third to a half century apart, but the meaning of intervals can only be really understood when volcanoes like Etna, Stromboli, and Vesuvius are grouped together. The same thing is true of Kilauea and Mauna Loa, and of Pelée and St. Vincent. Ponte reports the eruptions of Etna as ten years apart, similar to the sunspot interval; and Perret notes a ten-year interval for the smaller eruptions of Vesuvius. We measured an eleven-year interval for Hawaii, with culminations close to the minimum of sunspots. A culmination is when lava goes down and keeps quiet, or when sunspot numbers go down and remain few. No one knows why, or of any connecting cause.

Three eleven-year culminations make a third of a century, when at Kilauea and Vesuvius, something bigger happens. Sunspots have numbered a suspiciously similar curve at corresponding dates.

Photographs of Vesuvius taken just before the 1944 collapse showed the 1906 crater hole completely filled and overflowing. There was an inner flat floor, a conelet standing in the middle. The 1944 eruption collapsed the conelet, split the big outer cone, and sent flows to destroy San Sebastiano and several villages. The torrents of ash killed people and the electric station of the funicular railroad was destroyed, as usual. The mountain split in several directions.

Just as in 1906, the stages of the 1944 outbreak were lava flows, mixed lava gushing intensely liquid, crateral caving in, tremendous gas emission, black ash changing to vapor and white ash as the emission increased, and ultimately white steam. The black ash was the contemporaneous lava with dark augite; the snowlike white ash was ground up old lavas, containing the white crystals, leucite.

The liquid phase took an unusual fountain form, resembling that of Mauna Loa in Hawaii, and nine spells of bright incandescent explosive fountaining occurred. The collapse began on March 13; the fountaining occurred during March 20 to 22, with jets of bright liquid lava and flames, 1,000 to 3,000 feet high; and the crater became a lava lake. The flames were occasioned by hydrogen within the lava itself, and perhaps some carbon gases. This liquid fountaining phase was the culmination of explosions, making pumice, with water vapor the gaseous product. Ash fell four feet deep three miles away, and some fell on the Adriatic coast. Both white steam clouds and black ash clouds arose with the fountains, white and black side by side.

The net effect was to leave a bowl 1,500 feet in diameter and 800 feet deep, floored with avalanche gravel. This reconstructed the funnel of 1906, and as in 1906, the height of the rim was 4,100 feet after eruption. In other words, the thirty-eight years had filled the vast crater, only to have 1944 engulf and eject the contents, and strew them down the slopes, adding an immense weight to the outer shell of the cone.

A hundred million cubic yards of lava was poured out, and 50 million cubic yards of ash now lie on the volcano. Three times as much was carried far away, and the volume of gases was ten times as great. The rock fragments, probably 200 times as great, were engulfed by avalanches.

The big achievement of an eruption is to wedge open a mountain, let the internal lava effervesce and go down, admit ground water, and make spectacular fireworks of burning gas and meltings. Release of pressure by splitting open the crust permits a great show of fiery foaming, but no geologist sees the profound accomplishment of lava sinking and flowing away by underground channels. It may flow out along the Mediterranean Sea bottom. At Vesuvius, it may slip through deep cracks in the direction of Sicily.

Certainly a periodic adjustment of the big system (Vesuvius-Stromboli-Etna) has taken place deep down in the earth, and the thirty-eight years of accumulation mean a stress by weighting down. The pressure of 100 million tons of stored lava inside a weak cone mountain and ready to effervesce with heat and give up its hydrogen is what science too often forgets.

The continental crack system between crust blocks and full of rain water is waiting to assist the crisis, while the blocks are poised over uprising gases of the ages. The gases of the ages, reaching to the core of the globe, are eternally melting the walls with white-hot core matter, walls of siliceous rock blocks 1,800 miles deep. In this system, Vesuvius is a tiny pimple. Incidentally, the 1944 earthquakes were recorded in largest number during the period when the liquid pumice fountains were in action in the nine different spells between March 20 and March 23. This means that the maxima of engulfing crater, seething slag, outrushing gas, crunching mountain weight, and avalanching inner walls were all happening together. The clogging of vents forced the ground water steam into pulsations. This could not last; the mountain blocks settled and resumed pressure, deep lava drained off, heat dwindled, and gas was relieved. The bigger volcanic system asserted its downward weight of the adjusted globe.

By making much of pulsations and thirty-three year intervals, we are dreaming of an ideal volcano such as might be constructed as was our geyser apparatus. But there is no question of the reality of tides in rock, as well as in ocean; of day and night; cold and sunshine; year and century. Continent and ocean are positive, globe and solar system are positive. The ideal volcano is part of a tidal system and is limited in size. Therefore science has a right to inquire how it happens that through centuries most volcanoes stay 4,000 feet high. It has a right to look for averages and periodicities, just as a doctor looks for respiration, temperature, and heartbeats.

Like men, volcanoes are not all alike, but both men and volcanoes are orderly organisms. The object of volcanology is to find order and relate the small orderliness to the big regularity of globe and solar tides.

My 1906 visit at the end of the Vesuvian eruption crystallized my lifework idea, begun at Pelée; but my accomplishment was dwarfed to triviality by that of Perret, whom I first met while he was assisting the Italian volcano observatory. He was a photographer and observer of rare merit. He had been living in Naples and photographing all the Italian volcanoes, and he had worked out a solar control diagram for predicting volcano tides. Italy had made a volcanologist out of a physicist-engineer. Discovery of Perret meant to me much more than any phenomenon of geology.

Frank Alvord Perret was an electrical engineer from Brooklyn, and a genius with an ordinary Kodak. He took at Vesuvius, by sheer daring, the most remarkable photographs ever made of an active volcano. His knowledge of astronomy, meteorology, and physics made him see in a volcano something to study close at hand, as Benjamin Franklin studied a thunderstorm. He developed and printed his photographs himself, and colored his lantern slides. He helped Matteucci, the observatory director on Vesuvius, and was decorated as Chevalier by the King of Italy. He tramped close to lava vents and explosion clouds, and took hundreds of pictures.

Perret and I had exactly the same conception of a volcano. We thought of it as a living organism to record, just as rainfall is recorded by the weather man. For our recording, we had to invent volcano instruments. Though the camera was Perret’s supreme instrument, he had been an electrical inventor all his life. Businessmen in Springfield, Massachusetts, financed his work in Italy; and I went to Springfield to lecture and encourage their research association, the predecessor of our Hawaiian association.

Perret photographed Etna, Stromboli, Teneriffe, Sakurajima, Kilauea, the Carib cones and other volcanoes, and performed heroic work at the Messina earthquake of 1908. When, in 1929, Pelée entered into another of its periods of exploding and heaving it was studied critically by Perret who had established a museum and observatory at Martinique. He finally settled down at his museum in St. Pierre, and was of great service at the Montserrat earthquake crisis of 1933 and thereafter. He was not physically strong and the volcanic dust gave him pneumonia, but several times he recovered from attacks. He died in New York, having been forced north by the second World War.

I also met the Yorkshire oculist, geologist, and photographer, Dr. Tempest Anderson, on Vesuvius in 1906. This was another happy meeting. He too was a skilled volcano photographer, and had taken pictures in New Zealand and Iceland with his privately built cameras, using methods of extreme originality. He afterwards made for me a camera with small glass plates, dark chamber, arm sleeves, no plate-holder, alpenstock tripod, bottle strip-testing developer, self-drying metal case, and great perfection of rigidity and focus. We were to meet again and again in different parts of the world. He became one of the British experts sent to Soufrière by the Royal Society. He died of typhoid on a volcano voyage to the Philippines.

Shortly after my Vesuvius expedition I moved from Harvard to become head of geology at Massachusetts Tech. My teaching overlapped that of Professors W. Niles and W. O. Crosby at Tech and Wellesley, while for a time I continued my Harvard work. It was at this time that I began to think of possible ways of financing an expedition to the Aleutian Islands and their forty active volcanoes. The year 1906–1907 was a time of financial boom, so I went to Calumet and Hecla, the great copper company of which Agassiz was president. To my astonishment they subscribed $1,000 to start the Technology Expedition. State Street and Wall Street raised this to $13,000 in ten days, and I learned much about the availability of money during a boom of the stock market. President Pritchett of Harvard approved the expedition, and I organized it for a sailing schooner from Seattle, with nine in the crew and seven scientists.

We set sail in the spring of 1907 and spent four months in that ocean of gales, fogs, rain, and cold between Dutch Harbor and Atka—the eastern half of the Aleutians. One man, Colby, was a bear hunter who explored the Alaskan Peninsula and reported on coal and gold. The scientists were two geologists, two mining students, a physician who was also botanist and entomologist, and an astronomer. They were Eakle, Myers, Sweeny, Vandyke, and Gummeré. The sailing master and mate were uncle and nephew, both Nova Scotians named Seeley. The following poem by the master tells the story better than I could.

We collected specimens and made notes on geology, magnetism, topography, weather, photography, ethnology, plants, insects, birds, ores, shipping, volcanoes and navigation—materials for years of laboratory study. The journal of the expedition, thirty-seven pages long with photographs, was published by the Technology Review.

Like every such volcano expedition, we were hampered by the necessity of using a sailing vessel, by bad weather, by rain which interfered with photography, by long spells on the open sea in fog, and by inaccessible craters amid the ice of mountain tops. From the administrative viewpoint, two things stood out: the need for an amphibian boat, independent of harbors, and the need for a land station more or less permanent, wherefrom an amphibian boat could operate to reach and land on determinate beaches. A permanent station could work on specimens in bad weather. These discoveries determined the policy that was to eventuate in the Hawaiian Volcano Observatory, to the building of amphibian boats, and to five other Aleutian journeys by 1932.

I might describe sliding down the slippery grass of Unalaska, on the steep slopes peculiar to the Aleutians; exploring ice craters on top of Makushin in Unalaska; or getting storm bound for five days trying to reach Atka’s Korovinski Volcano on foot. But these tales have been published elsewhere.

The most exciting of the Aleutian volcanoes is Bogoslof, a peak submerged north of Umnak, with its crater, a line of erupting crags, just at sea level. We had good luck with weather and landed on Bogoslof in the forenoon of August 7, 1907. Hundreds of sea lions, bellowing close to the dories, would pop up and stare at us and then plunge frantically beneath the waves. On the beach we found one bull asleep, but he awoke and awkwardly floundered to the sea. The islet was then four peaks with sand flats between, the central one a steaming mass of lava protuberances shaped like potatoes. Next to it was a half cone broken in two, with a horned spine like a shark fin; Pelée all over again. It was also similar to New Zealand’s White Island. At the two ends of the island were older, peaked lava rocks. The active heap was 450 feet high with bright yellow coatings, and a ring pool of hot salt water around it, yellow with iron-stained mud. The rocky cliffs were covered with thousands of murres, their chicks, and eggs; and the birds darkened the sky in flight. The stench from offal and rotten eggs was intense.

The sea was full of fish, the beaches were full of sea lions, the hot lava and air were full of birds. Thus life and deadly volcanism lived together. The active rock was refractory basalt, semisolid, crusting and breaking into blocks as it rose from a submerged crater.

On September 1 after we left, the crater exploded, throwing sand and dust a distance of 100 miles to the east. The middle heap was engulfed, leaving only a lagoon; and the remaining peaks were shrouded in a heavy mantle of debris. Such a history of building and bursting and spreading out as a shoal has gone on for more than 111 years. Bogoslof is the peak of a submarine Pelée, several thousand feet above sea bottom. It is always active, the index volcano of the Aleutians.

It was about this time that the need for observatories began to be recognized. Something new and of grave menace had come into geology, terrible steam blasts capable of shooting out horizontally and explosively. And even as I write in 1952 these have been taking human lives at Mount Lamington in Papua and Mount Hibokhibok on Camiguin Island of the Philippines.

At Vesuvius, under Palmieri, an observatory had been established about 1859. The director was interested in meteorology as affected by Vesuvius, and annual reports were published irregularly. Successive directors became interested in making instruments for volcano science and Mercalli, the director in 1907, published a book in Italian on the active volcanoes of the world. When I went to Mount Pelée I was mindful of the venture at Vesuvius; and Professor Lacroix of Paris established artillery officers near St. Pierre ruins after the disaster, to watch and report as a volcano observatory. They furnished details and photographs of the many eruptions and the growth of the lava dome and spine. Doctors Hovey, Flett, Anderson, Lacroix, and Heilprin returned to Mount Pelée and added much to the observational and photographic record, and Dr. Stübel published a special book inspired by critical study of the Caribbees, in comparison with Andean volcanoes.

Hovey and I put through a resolution in 1907 at the meeting of the Geological Society of America, “strongly recommending the establishment of volcano and earthquake observatories.” Perret and I were both inventors of instruments, both experimenters, and both convinced that the expedition method alone would never solve the volcano problem. The brothers Friedlaender of Zurich were establishing a “Zeitschrift für Vulkanologie,” in Naples, and a laboratory with German, Swiss, and Italian assistants. The Carnegie Institution established in Washington a geophysical laboratory devoted to high temperature physical chemistry. We others were influenced by field ambition, and since 1899 I had fought for a Hawaii geological survey, for I was convinced that Kilauea Volcano there must have an American volcano observatory.

My experiments on erosion, sedimentation, deformation, and eruption convinced me that a field experimental science was bound to grow up in each of those parts of dynamical geology. All of these needed field observatories to determine index of erosion, index of sedimentation, index of ground movement and earthquake, index of volcanism; these indices to be quantitative just as the thermometer and barometer and wind gauge made climatology a quantitative science of the air. I found almost nothing being accomplished in these new field sciences. No one dreamt of attacking the Mississippi as a field of pure science of erosionology, compared to the Amazon. It was felt that these things could be left to commerce and the engineers.

By index of eruption I mean the geographical peculiarity of Vesuvius, for example, as an eruption center. Perret tried to reduce this to diagram form. I published, in Washington, a plea for geophysical observatories.

An earthquake in 1908, predicted and photographed by Perret, had killed 125,000 people in Italy at Messina, near Mount Etna. Hence I felt more strongly than ever that something must be done. So it was that in 1909, at my own expense, I made a journey to Hawaii and Japan with my family. Everything within me converged on making a life work of the results of my Pacific journey.

In Honolulu I was invited to show my colored lantern slides of the Mount Pelée disaster and to describe Massachusetts Tech’s plan for a seismograph station on Blue Hill near Boston. When the Honorable L. A. Thurston of the Pacific Commercial Advertiser interviewed me after the lecture, and asked whether Kilauea Volcano on the island of Hawaii would not be better than Blue Hill, I replied that it certainly would have many more earthquakes and, in addition, would offer volcano lavas to observe in action. Thurston asked, “Is it then a question of money?” I replied that it was, largely, but that it also entailed persuading Tech authorities that I was right.

After visiting Kilauea, where I stayed at the Volcano House and saw Halemaumau lava pit in action, I went on to Japan. There I visited the seismograph stations of Professor Omori and traveled to active Tarumai Volcano in Hokkaido. Tarumai, which was undergoing an interesting eruption at that time, is a 4,000 foot cone in pine forests on the north island of Japan. (Notice the usual 4,000 feet.) It had broken out explosively, sent up a great spiral of cauliflower clouds of steam and ash thousands of feet, and followed this by piling up a lava dome in its summit crater, the dome lifting the crater floor and protruding above the top of the mountain.

This was an extrusion of andesite, more refractory and giving hotter steam than Kilauea vents, as measured with an electric thermometer. We got 450° Centigrade with Bristol thermocouple in sulfur-covered cracks hissing on the actual face of the lava dome. Kilauea had given 300° Centigrade in the famous “postal card crack” where visitors browned their cards.

The stiff rising lava dome of Tarumai was a duplicate of the lavas of Bogoslof and Pelée, but Bogoslof was a crater at sea level, and Pelée’s big dome and spine above the mountain top developed in the second year of eruptions. I found further inspiration in a visit to Asama volcano in central Japan. Here, just as at Tarumai, the hard lava lay in a rigid swirl, hissing and steaming at the bottom of the summit crater after the crater had announced eruption by “cauliflower” uprushes.

It was evident that hard lava push-ups from the bottom of craters were characteristic of the Pacific and Carib shores, in contrast to Hawaiian and Italian flow-downs. The pressure upward breaks a mountain, the slag and boiling groundwater inside churns up avalanche gravel and dust, columns of dust-laden steam rush out, the break-up lets up lava, and according to its frothing gas and heat and the air temperature, it is capable physically of either foaming out liquid through radial cracks or pushing up semisolid and piling as an aa heap.

The net effect is flat lava shields for Hawaii, with flows into and under the ocean, and shapely high cones for the Andes and Japan, with Italy somewhere in between. The difference in the lavas is a matter of internal meltability, due to chemistry and gases.

In the first decade of the twentieth century this was new to me as a geologist, for the books did not explain internal gas in lava. Geography understood nothing of the relation of a volcano to lines of cracking earth crust and depth of crust, and gigantic explosions dominated history as exceptions. Refractory slags were then believed to be stiff by reason of chemical fusibility, and gas in solution in a melt is not understood even today. The Japan journey explained the textbook contrast between oceanic Hawaii and continental Ecuador, both volcanic, and the further contrast with Yellowstone agglomerates, and intrusions of the Black Hills of South Dakota. Clearly Hawaii must be studied, and experimental geology extended to the globe as a laboratory.

On my return to Honolulu, Professor Ralph Hosmer, forester, met me and reported that Honolulu money was available, if Massachusetts Tech would send me to Hawaii to found a volcano experiment station. Then and there the Hawaiian Volcano Research Association formed by business leaders in Honolulu became a reality, to crystallize later into an educational corporation.

In 1910, while I was still a professor at Massachusetts Tech, the United Fruit Company invited me to go in one of their ships to study the earthquake destruction of Cartago, Costa Rica. I saw an opportunity to study seismology in the field, as I had studied volcanology in Martinique. The United Fruit Company owned the railroad and much of the national debt of Costa Rica. F. R. Hart, treasurer of M. I. T. and director of the fruit company told me to make my own plans and the company would pay all expenses. Knowing that engineering is of first importance in earthquake disaster, I invited Professor Charles Spofford, head of our Civil Engineering Department, to go with me, and he promptly accepted.

Our journey was from New Orleans, in one of the splendid snow-white steamers of the fruit company. This ship, going by Belize in British Honduras, took us to Limon on the Caribbean side of Costa Rica, a place of banana plantations and Jamaica-negro labor. From Limon we took a mountain-climbing, narrow-gauge railroad, to the high and healthful capital, San Jose. We passed the ruins of the city of Cartago, with its earthquake tumbled churches and wrecked lower buildings, all covered with heavy roofs of red tiles. Don Anastasio Alfaro, government scientist, showed us seismographs and maps, and we called on President Jimenez, who owned a dairy farm on the high slopes of Irazu Volcano directly above Cartago. I arranged with the President to have the government make an official inquiry all over the Republic, suggesting a study of ten grades of earthquake damage, adapted to Central American habits. These grades, from mere alarm up to wrecked churches, were to apply to what had happened in each place. According to the answers, we would make for each place a numerical value of intensity and plot these on the map.

We visited the wreckage of Cartago, where the quake had come like the crack of a whip on May 4, 1910, just at the supper hour. An American railway conductor and his family were seated at table and with the first jarrings, they all pitched forward under the dining room table. When the low adobe house fell on top of them, the table saved their lives. A pathetic object was the hollow square of the Carnegie Palace, designed by a Costa Rican architect to promote Central American peace. It was improperly braced, and everything came down, including the ornate stone wall around the grounds; and a cracked gate post held a melancholy buzzard in the hideous ruin. This and several of the big churches, cracked and disrupted, gave Spofford food for his architectural notes.

The President’s farm on Irazu was a lovely place of green glades, fat cattle, and attractive Spanish dairymaids, at an altitude of more than 9,000 feet. The crater of Irazu at 10,300 feet was a tumbled depression on the top of the mountain with a steaming solfatara on one side, and a lot of circular holes inside, within a rim more or less circular.

Poas crater was very different, with a crater lake of boiling water surrounded by bright-colored horizontal layers of ash. We found buried bombs from a recent eruption which had punctured the soil with holes one or two feet across. There was wild adventure for me in being given a horse at 4 A.M., equipped with a rotten saddle, which slipped when I mounted him. The horse resented me in the early morning darkness, having just left his grain, and immediately bucked off both me and the saddle. More adventure followed. On the ride up the mountain and in the midst of the forest we encountered a jaguar trap which had recently caught two big cats. It was a pen, roofed with logs baited with a fowl, and disguised with brush; a shutter fell and closed the opening when the bait was touched. On the way down we had a terrific tropical thunder storm, with sheets of cold rain, and I got chilled to the bone and was sick with dysentery for two or three days.

There are a dozen volcanoes like these two on the backbone of the Costa Rica rocky mountains. They trend in a ragged line from the Panama boundary on the southeast, to Nicaragua on the northwest. All have records of explosive activity, but lava flows are rare. Beginning at Nicaragua the line of the Cordillera, capped with volcanoes, continues through Salvador, Honduras, and Guatemala; and some of the lower ones have lava flows. Cosequina is famous among them; and conspicuous as a frequently active volcano is Santa Ana in Salvador, one peak of which is Izalco, the index volcano of Central America, erupting frequently. Other index volcanoes are Kilauea for Hawaii, Stromboli for Italy, and Bogoslof for the Aleutians. The next line of volcanoes, also trending northwest, extends from Guatemala into southern Mexico. The Costa Rica line overlaps the northeast side of the Nicaragua-Salvador line, and this in turn overlaps the Guatemala line, and so on. The chains of volcanoes are over an echelon of cracks, surmounted by heaped-up lava peaks on the continental divide.

From the point of view of experimenting with volcanoes, the exploration of the Cartago earthquake and Poas and Irazu craters and a study of their relations typified the unsatisfactory combination of upheaved mountains of strata and of volcanic eruptions and underground friction. This extends all the way along the Cordillera from Patagonia to Alaska. I say unsatisfactory because from the science standpoint, the action of eruption or earthquake is far scattered in time and place, and only local observatory geophysics and traveling scientists will do the work. Cartago is directly at the foot of Irazu Volcano, but the volcano did not erupt simultaneously with the earthquake. In the same way Messina is at the foot of Etna, and Tokyo is at the foot of Fujiyama; and the great earthquakes do not accord with eruptions. Sakurajima in 1914 was an exception, it had a quake after outbreak.

The direct outcome of my study, on the map of Costa Rica, of lines of equal earthquake effects, showed the maximum of the 1910 quake on the continental backbone, and the lines were crowded together along the western mountains. However, they spread out wider and wider along the Caribbean coastal plain, which is an elevated sea bottom on the northeast side of the country. In other words the terrific jolt was a deep slipping or scraping under the volcano line, and the elastic waves of like strong effects were close together in the mountains on the Pacific side, opposed by hard rock. On the other hand these waves, much feebler, widened out their lines in going through flat, soft strata on the Caribbean side. The answer seems to be that along the jagged rupture which underlies the volcanoes there is continuous upward pressure of lava, which occasionally is accelerated into a big bump or slip, now here, now there, as the whole great mountain range volcanically heaves through the ages.

Our next journey was from Barrios across to Guatemala City, where we had distant views of such volcanoes as the pure cone of Agua and the sharp peak of Santa Maria, which in October of 1902 had blown out its flank and left a vast hole. The Guatemalan plateau of rich soil and abundant market products rises gradually from the wet banana lands on the Caribbean side to a height of 4,870 feet at Guatemala City. This is on the line of volcano cracks. Then the land plunges abruptly in a precipitous down-faulted slope, to a low flat shelf along the Pacific Ocean. This shelf is covered with the merging of many deltas formed by the streams and torrents which drain the well-watered plateau. Along this line at the top of the precipice is the chain of volcanoes, with rich coffee lands at their feet on the upper slopes. Coffee plantations were destroyed by steam, mud flood, and ash blasts in 1902, and similar destruction was destined to begin again in 1923.

A large model of Central America has been built in a park in the open air in Guatemala City, showing magnificently the upland plateau and its mountains, the flat slope to the east, and the long straight steep plunge to the Pacific coastal shelf. This is one of the best illustrations of the block faulting of a continent, lifted like a huge flat slab along a crack, and tilted away from the Pacific. The Pacific block dropped down.

The same structure is true, on a larger scale, of the line of the Andes, lifted as a volcano-covered slab, down-faulted along the Chilean coastal plain. The upland slopes away to the basin of the Amazon. In these studies we are experimenting with volcanoes on the scale of geography, but the principles involved apply to Mexico and to the Cascade Range in Oregon. They probably apply also to the Aleutian, the Kamchatkan, and the western Pacific arcs, considered as upheaved and eroded ridges. They are arcs because they are ancient calderas.

We traveled by steamer along the Pacific coast to Panama, where the canal was being finished. We were impressed by General Goethals and his associate engineers, and with the marvellous organization of big engineering as the United States could administer it. Yellow fever had been conquered, ships constantly brought dairy products from New York to canal employees, houses were screened and unglazed, and the jungle was cut back to limits of safety from the mosquitoes. We found lively young American college graduates, both men and women, playing tennis in the deep tropics, where earlier hundreds had died of fever. We arrived just at the time when sides of the Culebra Cut were continuously sliding inward like a glacier, to close up the ditch. The ground under a village at the top of the bank was cracking in long crevasses, and habitations had to be abandoned. The only answer was to dig away the hill with hundreds of dump cars, until the slope was flat enough to stop sliding.

An amusing episode occurred at the Pacific end of the canal, where giant monitors, or hose nozzles, were being used to cut away the banks. Engineer Williamson had conceived the idea of mounting these monitors on concrete barges made on the spot. He covered the frames with steel mesh, and sprayed concrete against the mesh until a water-tight hull was produced. Fellow engineers jeered at Williamson and said that a boat made of rock would surely sink. Someone asked Williamson, when his first barge bore up the heavy monitors and was successful, what he was going to name it. He painted the name in large letters on the barge “Ivory Soap, it floats.”

We met in Costa Rica and Panama Arthur Herschel, city engineer of Kingston, Jamaica, who was responsible for the reconstruction of that city after the terrific earthquake of 1907. Herschel invited Spofford and me to stay with him on our way home, stopping off when we passed Jamaica. We did so, were delightfully entertained, and learned about engineering and rehabilitation after the most intense earthquake of all history.

The momentary intensity of the quake had been utterly without warning, as though two mountains had collided, and the masonry of the business section of Kingston crumbled almost instantaneously. A British major was walking along the main thoroughfare, carrying a heavy walking stick, when at the other end of the street, he noticed a commotion and thought it was a negro riot. The disturbance came toward him with a roar, and he saw clouds of dust rise from the street like a tornado and approach him. He felt the ground jolting, raised his stick, and decided to stand and fight it. The buildings right and left simply exploded, and he was fending off bricks and stones and timbers. His feet were half buried in rubble, and he sat down on a steel girder which had lunged out into the street behind him. The dust was suffocating, the noise was a traveling roar which went past him and on down the street behind him. He called to a black man to dig out his feet, but the man rushed by with staring, crazy eyes. He heard screams and saw women running. It was some time before Red Cross stations were established and the army men rescued him.

The lesson taught by this earthquake, more intense than the one at Cartago, was that the wooden bungalows of the hilly suburbs on rocky ground stood the disaster better than even reinforced concrete in the congested waterfront district. The better built government buildings were preserved in part.

The Jamaica law of 1907 had established definite boundaries for wooden construction, limited to the suburbs, and made new and wider streets in the business district. It had also established rigorous fire insurance laws, and a city building code requiring specified construction for all masonry. The result was a marked ring of parkway separating the commercial center from the dwellings in the suburbs. The trouble with such legislation, the effect of which I saw in Kingston twenty-six years later, is that earthquakes are hopelessly discontinuous. With no more big earthquakes as testers, such laws become dead letter, a new generation remembers nothing, and an irresponsible and ignorant native population poses new problems of poverty and vice. Earthquake construction reform becomes an impractical dream. This is part of the unsatisfactory quality of earthquake science, where assistance to humanity is concerned.

So ends my expedition decade, 1901 to 1910, after a succession of studies in the field, which may be called Operation Pelée-Soufrière, Operation Vesuvius, Operation Aleutians, Operation Kilauea-Tarumai, and finally Operation Cartago. I did not think of these at the time as the strategic work of warring with a task force in geographical volcanology; but now as I look back on it, I can see in each expedition the organization of an institution and men, and progress of volcanic geology.