IN THE SUMMER of 1881, as James Garfield lay dying of an assassin’s bullet in the White House, a team of naval engineers was called in to solve a vexing problem: how to cool the President’s bedroom. The temperature in Washington was hovering above ninety, and the humidity was uncomfortably high.
Within a week of the shooting, working virtually around the clock, the engineers had rigged up a contraption that provided some relief. It consisted of a large cast-iron box, about the size of a coffin, which contained dozens of screens, each made of a thin layer of terry-cloth cotton. On top of this box was a tank holding more than half a ton of shaved ice, salt, and water. As the ice melted, it turned into a briny slush, which trickled down onto the terry-cloth screens. A fan at one end of the lower box sucked in air from the outside, which was cooled as it passed across the screens and was then pumped through a duct into the President s bedroom.