Army War College historian Tami Biddle explains,
Regarding Japan, we still told ourselves, Well, there’s lots of industry in cities, which is what the British had told themselves when they switched over to area bombing.
If you are a morally guided person, and you want to be able to sleep at night and reconcile what you’re doing with your own principles, you’ve got to find language and concepts to tell yourself that what you’re doing is okay…
The decision at that point was Okay, gloves come off. We have to do whatever we can do to bring this nation down.
Hoyt Hottel heard those whispers, those rationalizations. Did he read that Harper’s essay? He must have. The NDRC told him to investigate the utility of incendiaries as weapons of war, and so he decided—good scientist that he was—to put this new weapon, napalm, to the test. He set up one of the most elaborate experiments of the war: an incendiary demonstration test at Dugway Proving Ground, the Army’s eight-hundred-thousand-acre test facility in the middle of the Utah desert.
As Hottel recalled, “These generals don’t believe what scientists do. They only believe what they think they can visualize. We’ve got to build a Japanese village and a German village. It’s amazing the enormity of the effort that went into building those things.” They built two sets of perfect replicas of enemy houses on the sands of the Utah desert.
Hottel brought in top-level architects. For the German village, he called on Erich Mendelsohn, a brilliant German Jewish architect who had designed some of the most beautiful art deco and art moderne buildings of the 1920s and 1930s. For the Japanese village, Hottel conscripted Antonin Raymond, who had lived in Japan for years and to this day is probably Japan’s most celebrated Western-born architect.
Hottel recalled how much care went into the replica villages: “We decided that the two-inch-thick rice-straw mats that characterized the Japanese home, the tatami, were important because they were the major resistance to the bomb passage through one floor after another. So we had to have tatami.”
They built twenty-four Japanese residences—twelve complexes with two units each. They included shoji—Japanese sliding screens—and perfect replicas of Japanese window shutters.
Antonin Raymond also set exacting standards. Hottel recalled, “Raymond wanted the cabinetwork on making these things under his eye in New Jersey. Here we wanted to build a place in Utah, the wood was in the Pacific, the cabinetwork was to be in New Jersey—and these are absurdities.”
Hottel’s project manager, Slim Myers, was another perfectionist. “Slim said, ‘Damn it, we’ve got to be absolutely right. These generals are not going to stop us because we didn’t have something that was really characteristic. We’ve got to be right.’”
By the summer of 1943, Hottel’s model villages were ready for their tests. The military assigned a fleet of bombers to Dugway. One plane after another dropped its incendiaries. And after each round, the teams on the ground rebuilt whatever was damaged. Hottel first tried British thermite bombs, which were favored by the RAF commander Arthur Harris in his night raids on Germany. They compared those results with those of Hershberg and Fieser’s napalm, packed inside bombs that went by the name M69. Hoyt Hottel and his team stood by, keeping score.
Hottel recalled, “We early [on] decided that we couldn’t wait for the fire truck. We had to rush out to take care of fires. In fact, we had to rush out before all of the bombs had dropped.”
Hottel grouped whatever fire he saw into three categories of destructiveness: （a） uncontrollable within six minutes, （b） destructive if unattended, and （c） nondestructive. Napalm was the hands-down winner, with a 68 percent success rate in the first category on Japanese houses. It caused uncontrollable fires. By contrast, British thermite ran a poor, distant second. With napalm, the United States had built itself a superweapon. And the Army was so proud of its new bomb that it made glowing promotional films about it.
The main component of the M-69 bomb [is] a cheesecloth sock containing specially processed jellied gasoline. When ignited, the gel filling becomes a clinging, fiery mass, spreading more than a yard in diameter…It burns at approximately one thousand degrees Fahrenheit for eight to ten minutes…For air drops, the M69 is assembled in groups of thirty-eight…The cluster is released and opened, and the individual bombs, with gauze streamers trailing, drop toward the target.
3.
Imagine that you were a member of the Bomber Mafia and you happened to sit in on that demonstration test at the Dugway Proving Ground. You saw the meticulous reconstruction of Japanese villages. Heard the B-29s—your B-29s—screaming down the skies to drop their fiery payloads. You saw the houses engulfed in flames. What would you have made of it all?