How to Re-Create the First Intercontinental Weapon

DIY-history columnist William Gurstelle gives bygone weapons a modern spin.

- William Gurstelle

In November 1944, Japanese soldiers in a top-secret oceanside location loosed a set of balloons into the westerly winds. These globes, about 33 feet in diameter, contained a crude but ingenious device for releasing ballast that their inventors hoped would keep them airborne for three to four days—long enough to reach the United States. There, an onboard timer would activate, causing the balloons to drop their payload: incendiary bombs.