JF Ptak Science Books Post 2686
Well, this was just one King-Hell tough place to work. Not only were the conditions cramped, and the air not-good (and occasionally deadly), and dark, and humid, but the work itself was hard. The guys in the detail of this woodcut below were sweating away in an inverted box on the riverbed of the East River (NYC) with thousands of tons of stuff on top of the box. The box was actually a caisson1--a nicer French word ("case" or "chest") for the box--and it was a designed object for bridge construction for establishing solid footings for massively heavy towers under water. So the deal was the the caisson is a box upended, sunk down to the river bed, with space enough for men to work in in the free space in the caisson bottom. There would be air shafts and elevators to pull out excavated earth, and as the workers dug down, the caisson would sink, and with each movement enormous blocks of granite would be placed on the top of the caisson to help it sink further. And so this would be the process, digging down through a silty river bottom, pulling out the very heavy muck (having just done some little bit of work on a lake bottom I can tell you that the mud is extremely thick and heavy and difficult to maneuver), the caisson moving down as the earth was removed, continuing the process until bedrock was reached. And then, it was all filled in, more weight was added to the top of the caisson, until that special engineering sweet spot was reached that allowed you to start building the bridge's towers from which the bridge span would be suspended.
The work in this case shows the progress on the building of the East River Bridge, soon to be called the Brooklyn Bridge, in 1873, four years into the making, designed by an immigrant, John A. Roebling. The Bridge would be finished ten years later in a titanic task the story of which is beautifully told in David McCullough's Brooklyn Bridge (1980).
This was a very difficult job and absolutely vital job, not the least of which was the problem of decompression sickness, which affected many dozens of workers, and which was hardly understood. All for $2/day, which was a little better than standard pay for laborers (and equal to about $60/day in 2017 dollars so far as I can reckon, which is sorta/kinda minimum wage for 2008.)
So here they are, the guy on the right is hauling the muck to an elevator shaft at right (more visible in the full version of the woodcut, following), while another fellow shovels, and a third man strands there surveying the scene with arms folded in a pose recognized world-wide at construction scenes. The little squares above them show 12x12xX lengths of cut lumber, on top of which stone would be placed,
This is the full image from the massive (nearly 20 pounds) wrist-busting volume of Engineering for 1873:
Another image, this from The American Cyclopedia, showing the caisson at a more developed stage, and feeling that much more suffocating:
[Woodcut/drawing illustrating caisson used by W. A. Roebling in the construction of the Brooklyn Bridge. The American Cyclopædia, v. 3, 1879, p. 557 (Fig. 2).]
I can't help but include another image of a hard place to work, this one for the Thames Tunnel (from my post here: http://longstreet.typepad.com/thesciencebookstore/2012/08/beautiful-technical-illustration.html)
1. "Caisson: in architecture, a panel sunk below the surface in soffits or ceilings. In civil engineering, the term is applied, first, to a hollow floating box, usually of iron, which serves to close the entrances of. docks and basins; and second, to a box-like structure used in constructing or sinking the foundation of piers under water. Of the latter there are at least three different varieties: the ordinary, the bottomless or open, and the inverted, which includes the pneumatic. 1. The ordinary caisson is a large box with bottom and sides, made of timbers or planks, in which masonry is built and sunk to its desired position under water."--The American Cyclopædia, v. 3, 1879, p. 557