Plague in Paradise,1940's: the Weapon that Worked

Bubonic plague. In the 19th century it killed hundreds of people on Oahu. Only later did it spread to the Big Island of Hawai'i.

Throughout the early 20th century, from 1910 through 1950, the Hawaiian public health authorities waged war, with gases, bait poisons, and even with imported rat viruses, against the R. Hawaiiensis field rats around Hamakua, on the northeastern coast of the Big island.

 Yet they failed to make a significant dent in the rat population, and occasional transmissions of the plague bacteria Yesinia pestis via fleas to humans were generally fatal in those days, before antibiotics.

What finally seemed to eradicate the plague? Not removing the rats, but relieving them of their fleas, with DDT dust. How did they get the rats to dust themselves with flea powder, you ask? With the Rube Goldberg contraptions below:

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Source: Bulletin of the World Health Org., 13(1):49-68, 1955.