Doctor Wood. Modern Wizard of the Laboratory: The Story of an American Small Boy Who Became the Most Daring and Original Experimental Physicist of Our Day-but Never Grew Up

The “Wall Street bomb case” was a wholesale murder outrage that will never be forgotten by New York. Just before noon on September 16, 1920, a driver who passed so completely unnoticed that no description of him was ever obtained left a horse-drawn yellow wagon at the curb in front of the United States Assay Office, across the street from the Morgan bank. He hitched the horse to an iron block and disappeared, forever, in the hurrying crowds. A few moments later, with the street even more crowded, the big barrel bomb in the wagon exploded, killing thirty-nine persons, crippling scores, inflicting slighter wounds on at least four hundred — also damaging the Morgan bank, the United States Subtreasury and Assay Office, and other adjacent financial buildings. Wood’s account of his part in the case is as follows.

Some days after the explosion, Lamont, who had a summer home not far from mine at East Hampton and whom we had known as a neighbor for years, phoned and asked if I would go in to New York the following Monday morning and see if I could find any clues which might lead to the reconstruction of the bomb and the possible apprehension of the perpetrator. This was my first invitation to participate in a criminal investigation, and I doubted that I could be of any help. But Lamont felt differently. He had seen my laboratory in the old barn, had heard me talk about complicated phenomena in physics and the chemistry of explosives. I went down, as requested, and was first introduced to Sherman Burns, son of Detective William J. Burns, then director of the Bureau of Investigation, Department of Justice, who had been called in to work with the police.

Sherman took me to police headquarters, where I was ushered into the private office of Captain James J. Gegan, head of the Bomb Squad. Standing in front of me, beside Gegan’s desk, and leaning against the wall like a pair of old cavalry boots, were the two hind legs of the wretched horse which had drawn the cart containing a barrel filled with iron sash weights, with a high explosive bomb packed at its center. Gegan told me all they had found out, which amounted to very little beyond what everybody knew through the newspapers. The Morgan corner had been a shambles of dead and dying men and women. Nobody knew just what had happened. The troops had been called out, and everything was confusion. I asked Captain Gegan if they had subsequently found any fragments of the bomb’s structure or mechanism, since these if identifiable might lead to conclusions concerning the occupation of the perpetrator — might even be traced.

Captain Gegan said, “No. We’ve gone over a cartload of stuff, swept up in the street after the explosion. There were the sash weights, of course, but we’ve gone over the debris with a fine-tooth comb, and there’s nothing identifiable in the heap but parts of the wagon and harness”.

I asked him if he still had the stuff, and he took me into an adjoining room where there was a pile that resembled the dirt and scrap heap behind a blacksmith shop. It didn’t look promising, but I began grubbing. Presently I pounced on a fragment which I felt sure was a part of the bomb. It was a curved fragment of metal which might have been part of a thin-walled iron or steel cylinder, possibly eight inches in diameter. There was a hole in its center. On its outer surface and crossing the hole was a narrow lateral stripe, scored with deep parallel grooves or ridges. I had seen similar grooves on rock surfaces when studying geology at Harvard a quarter of a century earlier, which the professor called “slickensides”, formed on the opposed surfaces of rocks subjected to great pressure and undergoing lateral displacement. I showed this to Gegan, and said, “Here’s a part of the actual bomb”.

After further search, I found not only half a dozen similar fragments, but some pieces of a heavy steel hoop. One of them had a hole the same size as that in the first cylinder fragment and curved to the same degree, so that the hoop must have fitted snugly around the cylinder. Moreover, these hoop fragments were “slickensided” on the inside where they had been pressed in close contact with the outer surface of the cylinder when it had exploded. They had been drawn under heavy pressure against it, and this, as in the case of the rock surfaces studied in geology, had formed the parallel grooves and ridges.

I said to Captain Gegan, “We can now reconstruct the container of the explosive. It was a steel cylinder, probably a long one, eight inches in diameter, bound with steel hoops, fastened to it with rivets or something similar, passing through these holes”.