13
Knowing from the reports of other similar works that compressed air was liable to affect some men unfavorably, every known precaution was taken to guard against this danger.
—WILLIAM C. KINGSLEY
BY THE FIRST of June, 1872, when the Chief Engineer and the General Superintendent issued their annual reports, the Brooklyn tower stood one hundred feet above the East River at high tide, while on the opposite shore the lower edge of the New York caisson rested seventy-eight feet six inches below the same tidal mark. The General Superintendent in his report stated that 14,500 cubic yards of masonry had been laid on the Brooklyn tower in the year past and 13,075 cubic yards on the New York tower. The Chief Engineer, however, wrote as follows:
To such of the general public as might imagine that no work had been done on the New York tower, because they see no evidence of it above water, I should simply remark that the amount of the masonry and concrete laid on that foundation during the past winter, under water, is equal in quantity to the entire masonry of the Brooklyn tower visible today above the water line.
It was an impressive way to picture what had been accomplished, if not quite accurate, according to Kingsley’s figures. To be informed that something of comparable magnitude to the Brooklyn tower had been built unseen below the river was for most people to have all the abstract explanations of counteracting pressures and penciled diagrams of timber caissons replaced in an instant with a single vivid image that anyone could appreciate.
The massive, freestanding masonry tower rising at the edge of Brooklyn was still the only part of the bridge conspicuously on display. Through the whole of that spring, as charges of fraud and jobbery filled the papers and Brooklyn gossiped of bridge scandals, work on the tower had proceeded exactly according to schedule and the immense granite shaft was looked upon popularly as an irrefutable affirmation of all that had been promised and anticipated over the past several years. One look at something like this was enough to restore a person’s faith in what man could do and to make crooked bookkeeping and the like seem both terribly petty and no more than a temporary nuisance.
In plan the tower was an irregular rectangle, its outside surfaces being broken up by heavy buttresses. It stood lengthwise against the shore, 140 feet long, 59 feet wide. So at a height of one hundred feet, it was still broader than it was high, still only a little more than a third as high as it would eventually go, and only nineteen feet short of the height of the roadway. But already it was considerably higher than anything else around it.
Moreover, the tower kept gaining all the time, as though it were coming up out of the river, growing organically, instead of being slowly, methodically added to stone by stone. The change was never enough to notice from one day to another. Like the movement of an hour hand its progress was best seen at intervals. A Brooklyn dock worker on Furman Street might one morning notice that the stonework had gotten up above every ship mast since the last time he looked that way or a homebound commuter at the rail of a ferry pulling away from New York might realize one evening for the first time that this great blunt shaft with its feet in the water now topped the rise of the Brooklyn skyline.
The intended purpose of the structure would have been rather hard to figure at this stage if one did not already know. In the very early morning, when the ferries still had their running lights on and before anyone was at work on the tower, it might have been taken for an ancient harbor defense, a gray solitary battlement standing guard over the swarm of ships to either side of it. And when the sun began coming up and lit the top of the tower, the derricks bristling there looked for all the world like medieval war machines, the trajectory of which, from such a height, would surely be enough to hit New York. But in the full light of day, with the sun glaring on its clean buff-colored granite, the tower looked very new indeed, and more like the beginnings of a gigantic astronomical observatory perhaps, or the pedestal for some breath-taking triumphal monument.
But everyone did know its real purpose, of course, and could do little but marvel at its growth and at the way it seemed to diminish the size of everything else nearby. The ferryhouse, the most imposing Fulton Street stores, the newest business blocks, did not look so grand any longer. At the end of day, when the sun was a red ball hanging low over New Jersey and the west face of the tower seemed to be glowing from within, the granite pink nearly, everything in back of the tower stood in shadow for a block and more.
When the Eagle claimed there was nothing on earth, save the Pyramids, to rival “this Brooklyn tower of ours,” nobody thought that especially high-blown. And now Roebling had introduced a new vision to stir the public imagination. Now, one need only look at the Brooklyn tower and picture the same thing concealed below water directly across the river. As far as this tower reached above the river, the other one reached below, like a gigantic rock taproot. (Roebling undoubtedly wrote what he did a number of weeks before it was published, at the time when the Brooklyn tower was indeed at about seventy-eight feet.) For every stone the crowds on the ferry had seen hauled up the face of the Brooklyn tower, another had been added to the burden of the New York caisson. And those seemingly fearless figures working along the uppermost rim of the tower were no farther above the surface of the East River than the men in the caisson were below it.
Work inside the caisson was to be finished in another month. So it was the end of the first great stage in the building of the bridge, a clear dividing place. From here on the problems to be overcome, the work to be done, would be of an entirely different nature. Roebling made quite a point of this in his report, expressing congratulations to the Board of Directors “on the success which has attended the last of the two great tower foundations.” At the start of the work, he said, the foundations had been the principal engineering problem. The work to come—the building of the towers, the cable spinning, building the superstructure—was all work that had been done before on other bridges, on a smaller scale, “but upon the tower foundations rests the stability of the entire work.” Then he remarked almost as an afterthought, “Considerable risk and some degree of uncertainty was necessarily involved in their construction.”
All the extensive preparations for receiving the caisson had been completed by the end of the first week in September 1871. The tower was to fill a space formerly occupied by two ferry slips, between Piers 29 and 30. The riverbed had been dredged out to a depth of thirty-seven feet, or a little more than twice as deep as at the Brooklyn site. A hundred feet of Pier 29 had been torn away, and a huge pile dock had been built, itself a bridge more than a hundred yards long between the new foundation and the shore. At the end of the dock a square enclosure for the caisson had been built of six-inch pine planks—this to break the force of the tidal current, which was decidedly stronger on the New York side.
Borings made from the end of Pier 29 indicated bedrock anywhere from seventy-seven to ninety-two feet down. How far the caisson would have to go or whether even it was essential that it go clear to bedrock were questions that had still to be decided. But in any case the strata appeared to be chiefly gravel and sand, with layers of quicksand from fifteen to twenty feet thick. It was very different terrain from that at Brooklyn.
The machinery needed was all standing by on the dock: three huge boom derricks similar to those used in Brooklyn, the same clamshell dredging equipment as before, hoists, steam engines, and pile-driving gear. Workshops and offices had been built, a blacksmiths’ shed, sheds for cement, tools, general stores, a compressor house (the largest building) with its air-pumping machinery set up inside—thirteen Burleigh compressors ranged in a single row, each with its own steam boiler, as compared to the six compressors used for the Brooklyn caisson.
On September 11 the colossal wooden box was towed up from the Atlantic Basin, where in the four months since it was launched seven additional courses of timber, all laid with cement between, had been built on top. Once the pile enclosure was completed on the river side and the caisson confined to its permanent position, a final ten courses of timber were added, bringing the total height of the structure to just over thirty-one feet.
Particular care had been taken this time to guard against sea worms. The protection was needed only during the time the caisson was afloat and before it was entirely submerged below the riverbed, where the sea worm, the teredo, never penetrates. But this microscopic animal, less than a sixteenth of an inch in diameter, can bore into any crevice water can get through, so the precautions had to be quite substantial. Every outside seam was caulked. The entire outside surface was heavily coated with a composition of coal tar, rosin, and a hydraulic cement, which, all by itself, was supposed to have enough body and grit to dull the teredo’s boring apparatus. Then this had been finished off with a sheet of tin covering all four sides and the top of the sixth timber course. All seams in the tin had been soldered airtight and layers of tar paper had been put in both above and below the entire sheet. Finally, the whole caisson had been sheathed in four-inch yellow pine saturated with creosote.
“The great timber foundation was now complete!” Roebling wrote. “It contains 22 feet of solid timber above the roof of the air chamber, seven courses more than the Brooklyn caisson, and since the strength of such structures varies as the square of the depth, we may consider it to be nearly twice as strong as its Brooklyn brother.”
In their general features the two caissons were almost identical. The sides of the New York caisson were again of yellow pine and tapered from nine feet thick on top to an iron cutting edge eight inches wide. The timbers used in the roof were again a foot square. Headroom inside the work chamber was nine and a half feet as before. The base dimensions were 102 by 172 feet, making the new caisson just four feet longer than the one in Brooklyn. The heavier roof had been built to carry what Roebling figured would be a significantly greater load, since this caisson would have to go much deeper and therefore carry far more stone. But there were several other differences as well.
The light skin of iron boiler plate that lined the interior would not only provide fire protection, but make the caisson more airtight; and to improve visibility the whole inside had been given a heavy coat of whitewash. The water shafts this time, instead of being square, were round (they would be stronger this way Roebling had decided). In addition, some fifty iron pipes, four inches in diameter, had been installed throughout the work chamber as a way of removing sand.
In the Brooklyn caisson there had been no means of communication between the men below and those working up on the surface. But here Colonel Paine had devised a simple, ingenious mechanical signaling system. One of the sand pipes was capped below and an inch tube was passed through the cap with index pointers attached above and below. Underneath each pointer was placed a small plan of the caisson, showing the position of every pipe and shaft. By rotating this tube immediate attention could be called to any of the points. In addition, a small rod was passed down through the pipe and its weight offset by a weight above that was attached to a cord that passed over a pulley. Small indexes were then fixed above and below. These moved up or down on vertical boards on which were printed such messages as “stop,” “start,” “bucket is caught,” and so forth.
The arrangement of air locks was also quite different. This time there were two double locks, each large enough to accommodate thirty men, which meant that a full shift of 120 could enter or leave at one locking. And instead of being mounted on top of the caisson, as had been done in Brooklyn, the locks were built into the roof of the work chamber, so they actually projected down into the chamber about four feet. Each set of locks was connected to the top of the caisson by a spiral stairway enclosed in an iron shaft.
The arrangement was essentially the same as Eads had used in St. Louis and it was over this particular feature that Eads and Roebling were to have their bitter falling out. The advantages to be gained were these, supposedly: the men could now step directly from the air lock into the work chamber, and at the end of the day they would not have to make the climb to the top while still under pressure.
On October 31 the last timber course was finished, the first stone of the new tower laid. By December 12 enough stone was in place to hold the caisson on the river bottom at high tide. The compressed air was turned on and Roebling, Paine, Collingwood, and a complement of some thirty men went down inside. (Since the water was thirty-seven feet deep and the caisson with all its timber courses stood thirty-one feet high, this left the top of the caisson just six feet below water at high tide and about two feet below at low tide.)
Tearing out the temporary floor took another two weeks. When the digging began, the work proved nowhere near so difficult as it had been in Brooklyn, but much more disagreeable, for the caisson was standing in the middle of what for years had been New York’s principal dumping ground. Moreover, a street sewer was still emptying into the river close by.
The ground itself was a clay silt turned black by sewage and thick, with the putrid remains of animals, garbage, and what Farrington called “sewage abominations.” All this had been odorless so long as it was embedded below salt water, but once the black muck was turned over inside the caisson, the smell, even in the compressed air, came forth in all its original strength, as Roebling wrote. The stench was such that several men were actually overcome and had to be helped back up to the surface. Only by keeping a skim of water over the entire caisson floor could the men keep on working.
But beneath this foul dock mud, which was only a few feet deep, they hit clean river sand and gravel, and things took an immediate turn for the better. The skim of water was expelled by compressed air, leaving a perfectly dry footing, and by now, too, the lights inside were fully operating and in combination with the white roof and walls they lit up the entire chamber as bright as day. From then on the great timber box descended into the earth extremely rapidly.
Above ground the scene was one of great energy and purpose. A reporter described it this way:
At the foot of Roosevelt Street, where the New York tower is being erected, one of the busiest scenes in the city is met with and has been for months—dozens of workmen hurrying hither and thither with wheelbarrows and hods and spikes and shovels; engines puffing away, lifting huge blocks of stone with huge derricks from the barge at the side of the dock, drawing lumber from the foot of the pier, driving the piles of the cofferdam, and condensing and compressing the air to be used by the submarine workmen; men chopping and planing and sawing the immense timbers used in constructing the enormous derricks; others shoveling gravel and sifting sand for the cement; little knots of threes driving immense piles through the heavy timbers of the caisson with their sledges and kept steadily at work by an overseer who evidently enjoys his employment; some wheeling cement for others to lay between the large granite blocks, boring and hammering and cutting stone and carrying iron rails, everything indicating that the work is being pushed rapidly forward.
There were almost no boulders to contend with this time, indeed little else but sand. The average rate of descent would work out to about two feet a week, but at one stage, for several weeks, the caisson was sinking six to eleven inches a day. In the Brooklyn caisson, during the first discouraging month of excavation, the rate of descent had not averaged six inches a week. Now everything was working to perfection. The dredges had no trouble digging the pools below the water shafts and the sand pipes worked like a charm.
How the pipes were to be used exactly had been left undecided until it came time to give them a try. Either the sand could be forced out with water, using a new kind of sand pump devised by Eads, or it could be blown out by compressed air. The latter would be the simpler, less costly way, of course, if it worked. It would also greatly aid ventilation. An air chamber with an iron skin such as this one had inside would be practically airtight, but a certain quantity of new air had to be fed into the work area at all times to keep the atmosphere fresh enough to live in. In the Brooklyn caisson this had been no problem since air kept escaping under the shoe or into the timber roof. But compressed air lost that way did little work. Roebling’s thought, therefore, was that with all the compressors he had at hand, why not allow air to escape through the pipes and take sand out with it?
So the air system had been tried and after that there was no more talk of sand pumps. For everyone who remembered how it had been in Brooklyn this was the smoothest sailing imaginable. Morale could not have been better.
The sand pipes extended down through the roof and into the chamber to within a foot or so of the work surface. Sand, loose earth, and fine gravel were shoveled around the pipe in a cone-shaped pile two to three feet high. When the pipe was opened, the pile vanished up the pipe. It was as neat and uncomplicated as could be, and the deeper the caisson went—the greater the pressure in the chamber became—the better the system worked. When the caisson was down about sixty feet, for example, the air was blasting out of the sand pipes with such force that fourteen men could stand in a circle around one pipe and shovel sand under it with all their strength and the sand would disappear as fast as they could shovel. At least three sand pipes were kept going all the time and some sixty men did nothing but feed these pipes, which was about the most tiring work imaginable. Time and time again the pipes had to be shut off to give the men a rest.
Up on top the sand blasted out with such velocity that it became a serious problem. At first, when there were only vertical discharge pipes, the sand was shooting four hundred feet in the air. To deflect this great geyser off at right angles, so it would feed into big scows tied up beside the caisson, iron elbows were fixed to the tops of the pipes. But the furious blast of sand would cut right through these, sometimes in a matter of minutes. Iron an inch thick would not last a regular workday. When elbows fixed with thick caps or patches of a special chilled iron were tried, they lasted only two days. Toward the end of the work the elbows would be dispensed with altogether and heavy granite blocks would be placed on supports directly above the mouths of the pipes. The sand would strike the blocks, then fall back. But the sharp, abrasive force of the sand was such that in three or four days’ time it would cut a hole through the granite block.
Once, a man passing by in a rowboat, with one hand resting on the gunwale, had the end of a finger shot off by a pebble fired from a sand pipe. Another time a workman was drilled through the arm in the same way. And down inside the caisson Farrington at one point thoughtlessly placed his hand over the open end of a sand pipe and found he was unable to remove it. Only with several others pulling on his arm was he able to get his hand free and then found that his whole palm had been drawn up into the pipe like a stopper.
Boulders were encountered only on occasion and slowed things down but a little, except when one appeared directly below a water shaft. The shaft had to be capped then, the water removed, the boulder excavated out of the dry hole, the same as had been done so many times in Brooklyn. But relatively little time was lost that way. Paine’s “mechanical telegraph” between the men on top and those below worked amazingly well. “The downward movement of the caisson has been under perfect control,” Roebling wrote. Indeed, the work went smoother, faster than anyone could have hoped for. Everything functioned as it was supposed to in theory and as it seldom had in practice over in Brooklyn. Nothing very unexpected happened. The heavy, tiresome digging by the men inside and the noisy work of dredges and stone derricks up above continued day after day, six days a week, and on into winter. The caisson, itself as high as a four-story building, kept descending steadily, evenly, uneventfully, the lights inside burning twenty-four hours a day, and all the while an enormous load of limestone blocks piling up on its back just as steadily, evenly, and uneventfully.
As far as Roebling and his staff were concerned, there were only two problems to be considered—the effects of the compressed air on the men and the depth to which they might have to go before stopping. In Brooklyn every foot of ground gained had to be fought for and the physical discomfort of working under pressure had been but part of the problem. But here the mercury gauges on the big Burleigh compressors kept inching up just as steadily as the caisson was descending.
Every two feet gained meant a pound more of pressure. On December 18, when the caisson was grounded on the river bottom in thirty-seven feet of water, the pressure was at seventeen pounds. In Brooklyn the pressure had gotten up to only twenty-one pounds when that caisson was halted at a depth of forty-five feet. But here, where the water was so much deeper to begin with and the going so much easier, it took only about a month to reach forty-five feet. Even at that the bottom of the caisson was only eight feet into the river bed, which left twenty-three feet more, or the whole of the enormous timber roof, still surrounded by water. And bedrock was still a long way off. But at forty-five feet, just as at Brooklyn, some of the men began feeling a good deal of discomfort, and, in a few cases, severe pain.
The number of men employed at any one time in the caisson varied from fifty to 125 in the daytime and from fifteen to thirty during the night. At first the workday was divided into two shifts of four hours each, separated by an interval of two hours. But at forty-five feet Roebling ordered the workday for caisson men shortened slightly, to seven and a half hours, in two shifts. At fifty feet, with the pressure increased another two and a half pounds, the day was again cut by half an hour. The majority of men were having trouble by now. The climb up to the surface after each shift, for example, had become so terribly fatiguing that Roebling had one spiral stairway pulled out and a steam elevator installed, as Eads had also done in St. Louis.
It was not until late January, however, when the caisson reached a depth of fifty-one feet, that any serious effect among the men was observed. And it was at this point, when pressure in the chamber stood at twenty-four pounds, that Roebling decided there ought to be a doctor on hand.
His name was Andrew H. Smith. He was a New Yorker, a former Army doctor, a surgeon, and a throat specialist at the Manhattan Eye and Ear Hospital. He was a man about the age of Roebling. Nine years later he would achieve national prominence by performing the autopsy on President Garfield that revealed the much-debated location of the assassin’s fatal bullet. Smith’s pioneer work on the bends, however, would be of far greater importance. His title was Surgeon to the New York Bridge Company and, except for Dr. Jaminet, Eads’s medical adviser, and some other St. Louis doctors, he was the only man in the country with any medical background to try to figure out what was causing the mysterious malady brought on by compressed air.
Smith took his assignment very seriously and went right to work. His first step was to prepare a set of rules, just as Jaminet had done two years earlier in St. Louis. These he had posted conspicuously about the dock and inside the caisson. They read as follows:
1.
2. Never enter the caisson with an empty stomach.
3. Use as far as possible a meat diet, and take warm coffee freely.
4. Always put on extra clothing on coming out, and avoid exposure to cold.
5. Exercise as little as may be during the first hour coming out, and lie down if possible.
6. Use intoxicating liquors sparingly; better not at all.
7. Take at least eight hours’ sleep every night.
8. See that the bowels are open every day.
9. Never enter the caisson if at all sick.
10. Report at once at the office all cases of illness, even if they occur after going home.
He next subjected every man to a physical examination, the idea being to exclude anyone suffering from heart or lung disease, anyone who struck him as too old for such work, and all obvious drinkers. Every new caisson man thereafter was required to have a work permit signed by him; and though only a few were actually rejected, the knowledge that an examination and a doctor’s permit were required doubtless discouraged many who were unfit from applying.
In any case, Smith was convinced that the men he cleared were in the best possible physical condition. He also saw to it that each man got a strong cup of coffee every time he came up out of pressure. “It appeared to relieve, in a measure, the nervous prostration which marked the return to open air,” Smith wrote. He did his best, too, to get the men to stay quiet a while after each shift, in a special resting room he had fitted out. But once out of the caisson, the next stop for most men was the handiest saloon. There the terrible, numb fatigue or the outright pain the work left them with could be cured considerably faster, they believed, than taking the doctor’s coffee or spending time on a company bunk.
The young doctor had no misconceptions about the off-hours recreation of the men or the living conditions most of them put up with. Many, he knew, slept in “lodginghouses,” as they were called, a damp cellar likely as not or one of the 14,872 tenements described in the 1870 census, where thirty people to a room was not uncommon, where the only light and ventilation came from a single passageway up to the street or to an ill-smelling common hall or kitchen. The ages of the men, as Smith noted, ranged from eighteen to fifty. They were of all nationalities, he found, but mostly Irish, immigrants who had known nothing else in New York but tenement life. The neighborhoods they went home to after a day in the caisson were famous as breeding grounds for measles, diphtheria, scarlet fever, the grippe. And in the teeming streets the one note of cheer was the saloon. “The habits of many of the men were doubtless not favorable to health,” Smith wrote, “but everything which admonition could do, was done to restrain them from excesses.”
Smith had been down in the Brooklyn caisson once or twice at Roebling’s request. And now again, as at Brooklyn, he noted with much interest that when the men spoke to one another in the heavy air it was with strange shrill treble voices and that it was physically impossible to whistle. (“The utmost efforts of the expiratory muscles is not sufficient to increase materially the density of the air in the cavity of the mouth, hence on its escape there is not sufficient expansion to produce a musical note.”) He noticed, too, that the men were breathing faster under pressure, and suspecting they were breathing harder as well, he wrapped a steel tape about his own chest, then compared the measurements he got when breathing inside the caisson and up on the surface. Under pressure, he found, his chest expansion was nearly twice what it was normally.
He studied the effect on circulation and discovered that while the normal pulse might rise sharply upon entering the caisson, after an hour or so it would drop back to normal or even below normal. The effect on the volume of the pulse was to diminish it. This, he thought, was caused by the pressure exerted on the artery. “Hence, the pulse is small, hard, and wiry.”
He observed that the men coming out of the caisson all had a marked pallor that lasted twenty minutes or so and that their hands were slightly shrunken and the tips of the fingers shriveled, as if they had been in water for a long time. Inside the caisson he took the temperatures of several workers and found they were one, even two, degrees above normal. The whole force was running a fever, he concluded, and told them this was caused by the heavy, saturated air, which kept their bodies from cooling by evaporation as they would normally. It was the reason they were always wringing-wet with perspiration, he explained. It was not that they were perspiring so much more, but that the air was not drying them in the least.
Like others before him, Smith was also impressed by the way the work seemed to increase the appetite. This he believed was caused by a generally increased waste of tissue, which was the result of an increased absorption of oxygen. But he was not absolutely sure about that—or much of anything else. He had no reliable data to go by, as he said, nor were the men particularly cooperative. His means of testing his theories were quite crude at best. To find out what effect the heavy atmosphere had on the metamorphosis of tissue, for example, he took four healthy pigeons, cut a wound under the wing of each, took two down into the caisson and kept the other two in the temporary hospital he had established on the dock. But at the end of six days he could find no discernible difference in any of them. The wounds all had healed about the same; the birds appeared to be in comparable health.
A little later on he had a dog taken into the caisson and kept there for seven hours. Then he went down himself, killed the animal with prussic acid, opened its neck, took a blood sample, and carried that back to the surface to see what if anything had happened to its oxygen content. Small quantities of air injected into the blood stream of a dog would, he knew, normally escape through the lungs. But perhaps time under pressure produced air in the blood that could not be expelled in the normal fashion. His sample from the dead dog, however, indicated no such thing, so he abandoned that approach, little realizing how close he was to the truth.
But it was the suffering of the men that concerned him more than anything, and as the caisson continued downward, their suffering increased many times over. Smith was in daily attendance. He studied every symptom, kept careful notes, and though he was unable to put his finger on the exact chemical or physiological cause of the trouble, he began to have some ideas of his own about what the men were doing wrong and what might be done to help those suddenly “taken” by the effects of compressed air—“as if struck by a bullet” was the way they commonly described it.
One of the workers in the caisson about this time may have been an undersized Irish boy named Frank Harris, later to become a man of letters in England and author of the sensational autobiography My Life and Loves. Harris said he went to work in the caisson a few days after landing in America and was only sixteen at the time. He never wrote anything about the experience until years afterward, which may explain the inaccuracies in his account. But he was also known his whole life for his inability to separate fact from fancy, so what he says may or may not be the way things happened. * Still, it is among the very few accounts written from the point of view of the men themselves and vividly conveys the terrible fear they had of contracting the bends:
In the bare shed where we got ready, the men told me no one could do the work for long without getting the “bends”; the “bends” were a sort of convulsive fit that twisted one’s body like a knot and often made you an invalid for life. They soon explained the whole procedure to me…. When we went into the “air-lock” and they turned on one air-cock after another of compressed air, the men put their hands to their ears and I soon imitated them, for the pain was acute. Indeed, the drums of the ears are often driven in and burst if the compressed air is brought in too quickly. I found that the best way of meeting the pressure was to keep swallowing…
When the air was fully compressed, the door of the air-lock opened at a touch and we all went down to work with pick and shovel on the gravelly bottom. My headaches soon became acute. The six of us were working naked to the waist in a small iron chamber with a temperature of about 80 degrees Fahrenheit: in five minutes the sweat was pouring from us, and all the while we were standing in icy water that was only kept from rising by the terrific pressure. No wonder the headaches were blinding. The men didn’t work for more than ten minutes at a time, but I plugged on steadily, resolved to prove myself and get constant employment; only one man, a Swede named Anderson, worked at all as hard…. Anderson was known to the contractor and received half a wage extra as head of our gang. He assured me I could stay as long as I liked, but he advised me to leave at the end of a month: it was too unhealthy: above all, I mustn’t drink and should spend all my spare time in the open. After two hours’ work down below we went up into the air-lock room to get gradually “decompressed,” the pressure of the air in our veins having to be brought down gradually to the usual air pressure. The men began to put on their clothes and passed around a bottle of schnapps; but that I was soon as cold as a wet rat and felt depressed and weak to boot, I would not touch the liquor. In the shed above I took a cupful of hot cocoa with Anderson, which stopped the shivering, and I was soon able to face the afternoon’s ordeal.
Still, he could make two weeks’ wages in a day, he said. If he could last a month, he would have enough to live on for a year. But by the fifth or sixth day, he had terrible shooting pains in his ears and he was told he might be going deaf. An Irishwoman he was boarding with in a shanty beside Central Park fixed up a remedy—“a roasted onion cut in two and clapped tight on each ear with a flannel bandage.” Harris said it worked like magic, relieving his pain in minutes. But not many days later he saw one of the men fall and writhe on the ground, blood spurting from his nose and mouth, and that was enough to decide young Harris, who quit soon after and who later took the literary license to say that the man’s legs were “twisted like plaited hair.”
Smith assumed medical charge of the caisson workers on January 25, 1872, and was on duty until May 31, when he resigned. During that time there were 110 cases of sickness that he could attribute directly to compressed air and that were severe enough to require treatment. Not by any means, however, did every man suffering pain or discomfort report to him—as he was well aware. The feeling was that a man might not get hired again at some future time if it was known he had had a dose of the Grecian Bends. (It was a feeling that would also persist among future and supposedly more enlightened generations of “sand hogs,” a term not yet in use in the 1870’s.) As Roebling would write in his own report, scarcely any man escaped without being affected by intense pain in one form or other. Martin and Collingwood both suffered attacks. Charles Young, the foreman who had collapsed in the Brooklyn caisson the same time Roebling did, had again become so much affected by the compressed air that on the advice of his own doctor he resigned, taking a job overseeing work on the dock instead.
But those cases Smith was able to treat and study, he described at some length in his notebooks:
Case 11—E. Riley. Taken sick Feb. 16th, one hour after leaving the caisson. Pressure 26 lbs. Epigastric pain and pain in the legs. No loss of sensibility. Profuse cold perspiration. Pulse, when I saw him, two hours after the commencement of the attack, was 96. The pain, which at first was very severe, had by this time become much less. Gave him an ounce of brandy and a teaspoonful of fluid extract of ergot. In 10 minutes the pulse had fallen to 82. Was able to resume work the next day.
Case 12—Joseph Brown, foreman, American, aged about 28. Taken on the 28th of February, about an hour after coming up from a three hours’ watch. Excessive pain in left shoulder and arm, coming on suddenly, “like the thrust of a knife.” Pain continued until he went down again for the afternoon watch, when it ceased immediately….
Case 13—Henry Stroud, a diver by occupation, began work on the morning of April 2d. Half an hour after coming up from the first watch, was taken with numbness and loss of power in the right side, also dizziness and vomiting. This was followed by severe pain over the whole body. Excessive perspiration. Was treated with stimulants and ergot, and in five hours was well enough to return home.
Case 14—John Barnabo, Italy, 42, reports on the 13th of March, while in a car returning home, he was taken with severe pain in both arms. This was followed by dimness of sight and partial unconsciousness. Extremities very cold. Remained in this condition for two hours. Was obliged to keep to his bed for three days. For a week afterward was unable to work, feeling very much oppressed about the chest. Had no medical attendance. Had a similar but less severe attack about a month previously.
Savage cramps in the legs were the most common first sign. Sometimes the pain lasted all night, in the knees mostly, and it felt as though the joint was being violently twisted apart and every muscle torn away from the bones—or worse. There was really no way to describe the pain, most men said. A modern medical textbook describes the pain as deep and relentless, and not throbbing. “When it is severe, local numbness, weakness, and faintness resemble the sickening pain of a blow on the testicle.”
In one out of four cases the attack was accompanied by dizziness, double vision, and repeated vomiting. All of a sudden a man would begin to stagger, bend double, retch horribly, and fall. Sometimes there was no pain at all, just a massive numb feeling and an inability to walk or to stand upright.
The victim of an attack always looked the same, whether there was pain or not, the face a leaden color with cold beads of sweat standing out all over, which were probably signs of impending shock. Men complained, too, of excruciating pains in the chest and bowels. Some had their speech affected, as though they had had a stroke. In numerous cases the joints—knees, wrists, elbows—were swollen all out of shape, burning hot to the touch, badly discolored, and extremely tender.
By the first week of April the caisson was down past sixty feet, still descending steadily, and conditions had grown very serious indeed. The remedies Smith employed were all very simple. To alleviate pain he promptly administered ergot and often in quantity. Or he doled out whiskey and ginger. Or he gave injections of atropine, a poisonous alkaloid used as an antispasmodic. When nothing else worked, he used morphine. Since the average attack generally lasted only a few hours, his solution for severe cases was simply to drug the patient so heavily that he felt little or nothing.
He applied hot poultices to swollen joints. Paralyzed legs were soaked in hot baths, arms were packed in ice, spines were doused with ice water. Men with heaving stomachs were spoon-fed bits of ice or “a scruple of calomel,” i.e., twenty grains of a white tasteless purgative. Sometimes these things worked, or seemed to. But the prevailing attitude among the workers and the engineers in charge was that it did not matter much what Smith did. As Collingwood noted at a gathering of the American Society of Civil Engineers later that spring, almost every man recovered eventually anyway, regardless, it seemed, of how much or how little was done for him.
In a few instances, when a man reported back to the job after recovering from an attack, Smith told him to find other work. Patrick Rogers, for example, a forty-year-old Irishman from Brooklyn, was on his way home on the ferry one night when all at once he had no feeling at all in his right side and very quickly after that was unable to stand up or move a muscle. When the boat docked, he was placed in a horse cab and taken home. As with most of the cases Smith recorded, the pain Rogers was in, terrible as it was, lasted less than twelve hours. But when he returned to the caisson, ready to go down again, he told Smith of a continued “trembling” in his chest and Smith advised him to go away and not come back.
A number of other Brooklyn men were sent by Smith to the Brooklyn City Hospital, where, interestingly, the cases became the special fascination of a young intern there, Dr. Walter Reed, later to be one of the best-known physicians in the world as a result of his research on yellow fever. Like Smith, Reed also kept extensive notes on each caisson victim to come under his care and these he subsequently turned over to Smith. As Roebling would write, it was hoped that Smith’s efforts and conclusions would be made public eventually “for the benefit of future works.”
Smith never used the term “bends.” He called it the caisson disease, a name he was the first to employ and that is still used as the formal designation. He did a commendable amount of original research into the history of the subject and was thoroughly familiar with what Jaminet had written in a lengthy report published in St. Louis the previous year. * Smith described Jaminet’s observations as “exceedingly valuable,” but found it “especially to be regretted” that Jaminet’s basic remedial routine had been merely to keep the patient lying on his back with his feet elevated slightly and to administer whiskey or beef broth.
From what he read and from his own observations Smith put together a number of theories, several of which were the same as conclusions reached in France some twenty-five years earlier. The disease, he decided, depended upon increased atmospheric pressure, but always developed after the pressure was removed. Attacks never occurred while the men were still under pressure, only afterward—as had become obvious to almost everyone. So there was a very good chance, he decided, that the principal cause of the trouble was “locking out” too rapidly. “Indeed,” he wrote, “it is altogether probable that if sufficient time were allowed for passing through the lock, the disease would never occur.” This, he knew, jibed with what the French mining engineer M. B. Pol had concluded in 1845 and later expanded on in a most interesting memoir published in 1854. “Experience teaches,” Pol wrote, “that the ill effects are in proportion to the rapidity with which the transition is made from the compressed air to the normal atmosphere.” In St. Louis Jaminet too had hit upon the same idea after being taken by a terrible seizure himself, but Jaminet thought it even more important to increase the pressure slowly when the men were going in. Smith it seems never suffered any discomfort from his time in the caisson.
To make things easier for the men after they emerged from the lock, Smith recommended that no climb up a long flight of stairs be necessary at that point. To have put the locks at the bottom of the shaft as Eads had was a serious mistake, he said. The arrangement in Brooklyn had been better. That way the climb was made “in the compressed air, instead of immediately after leaving the lock, when the system is more or less prostrated.” The elevator Roebling installed had been a wise measure, but it had not wholly alleviated the problem.
But Smith did not see how, in all practicality, the locking-out procedure could be changed much. What might be sufficient time in the lock for one man, he reasoned, would be too short for another, and far less work would be accomplished if the time in the lock were prolonged greatly. Delays would be very expensive for the Bridge Company. Besides, the men themselves would want no part of it. About all that could be done, he concluded, was to make the time required in the lock proportionate to the pressure. But even that time could only be “as great as is consistent with the circumstances.” For the New York caisson Smith established a regulation that at least five minutes more in the lock would be allowed for each additional “atmosphere,” or for every additional 14.7 pounds of pressure, which meant that for every three pounds of pressure added inside the caisson, Smith wanted the men to take a minute longer coming out. So at a depth of, say, sixty-five feet, with the pressure at thirty pounds, the men should spend five minutes in the lock on their way out; at seventy-five feet, with the pressure at thirty-three pounds, they would spend perhaps six minutes. Smith was not asking for very much, in other words. Even so, the regulation was followed only infrequently. “The natural impatience of the men to reach their homes,” he wrote in a tone of despair, “makes the delay in the lock irksome, and great firmness is required on the part of the lock tender to prevent the escape cocks being opened more widely than is consistent with safety.” One of the first steps in such work, he said, ought to be the employment of reliable lock tenders.
But despite his recognition of rapid decompression as the chief cause of the mysterious sickness, Smith remained convinced that susceptibility was still largely a matter of “special predisposition,” as he called it. Some people, he said, were simply more susceptible than others. It was commonly known, he said, that certain people had a predisposition to pains in the joints just prior to a thunderstorm. These pains, as he said, were generally considered to be of rheumatic character and caused by dampness, but Smith now thought differently. The pains suffered by his caisson workers were precisely the same, he said, only, of course, immensely intensified. So very likely anyone who could feel weather in his bones was actually feeling shifts in atmospheric pressure, and just as some people could feel such things and others could not, so some people would fall victim to the caisson disease while others would not.
Fat people and heavy drinkers, he was convinced, were more susceptible than anyone else. Men new to the work also stood a greater chance of being hit by an attack than those who had been going into the caisson for a length of time and so had had the pressure build up on them slowly. New hands suffered worst during the first week he noted. The ideal caisson worker in his view was a spare man of medium height in his twenties or thirties, a description that would have applied to Washington Roebling, among others.
But of more importance was Smith’s contention that the amount of pressure a man was exposed to and length of time spent in the caisson were as much a part of the problem as rapid decompression. So in this he agreed completely with Eads, Jaminet, and Roebling. “The testimony of all observers,” he wrote, “is that the liability to attack is directly as the duration of the stay in the caisson.” The common explanation given for Roebling’s collapse in the Brooklyn caisson the night of the fire was not that he had been coming up too fast, but that he had been staying down too long. Smith concurred with the explanation. In fact, the explanation followed perfectly out of the conclusion he had come to concerning the real root of the problem.