The iconic bomb entered the public imagination after the Civil War:
Ignited, uncontained gunpowder will burn, but for it to explode the gas pressure needed to be built up in a sealed container. Often, a spherical one made the most sense, since the shape was aerodynamic and could be made of two halves with one seal, instead of a box with many sides.
They were also dark, being made of cast iron or other metals, both to ensure sturdiness and to maximize shrapnel after the explosion. The only thing inaccurate about the cartoon depiction of bombs is the string wick, says Kelly. “Fuses were made of wood and they’d be drilled down through the center, and they’d be packed very solidly with gunpowder that would burn at a predictable rate,” he says, “The idea of a string fuse coming out of the bomb is really a fantasy.”
If the Civil War was the last gunpowder war, given the sheer number of Americans involved, it seems likely that many would have some familiarity with an explosive of that kind. But another aspect of American culture helped to popularize that image — editorial cartoons.
By the mid-19th century, many papers across the country featured editorial cartoons. The most famous was probably Harper’s Weekly, often considered the most widely read publication during the Civil War. Their illustrations featured caricatures of politicians, depictions of the treatment of slaves, and of course, battles. In one cartoon, a smoking bomb with the face of who appears to be General Scott is lobbed toward Jefferson Davis. The bomb is round with a skinny, string wick sticking out of the top. Comics like that made it pretty clear just what a bomb looked like.
In 1867, Alfred Nobel invented dynamite, which Kelly said was quickly and widely “publicized at that time as the weapon of the people,” something easily accessible and easy to make at home. It seems that spherical gunpowder bombs would be on their way out. But another widely publicized event may have sealed their images in the minds of the populace. In 1886, a labor demonstration in Chicago’s Haymarket Square was thrown into riot by a dynamite bomb, but one that reportedly resembled a stereotypical mortar bomb. According to the New York Times accounts of the riots, a group of men arrived on a wagon, and from it “something rose up into the air, carrying with it a slender tail of fire.”
Three days after the bombing, police searched the house of anarchist Louis Lingg, who was suspected to have made the bombs, and found two spherical dynamite bombs with metal casings. Given that dynamite is enough of an explosive, the metal casings were likely not used to hold in pressure, but to cause damage as metal shards flew into the crowd. The prosecution used these bombs as evidence in the trial of eight suspects, and testified that they matched the chemical makeup of the bombs used in the Haymarket riot.
The trial was heavily covered in the press, and again Harper’s Weekly provided images. In one, a bearded anarchist is seen standing over a spherical bomb, and in another Lady Justice holds one labeled “law” over a panicked crowd. It didn’t matter if they were gunpowder bombs or not. The image was the same.