the history behind the cloud Atlas
There really were such balloons. (If you're asking, "what balloons?" then head back to "about the book".)
Shortly after New Year's Day, 1945, the United States' Office of Censorship issued an unusual and urgent bulletin: media outlets were requested to report absolutely nothing about the strange flying objects that had begun to appear through the western United States in the past two months.
What may strike people today as even more unusual is that this request was universally obeyed. Despite the fact that strange flying objects--in fact, bomb-laden Japanese paper balloons--were then landing daily throughout much of the United States and Canada, the nation's press stayed mum.
Even though the gag was removed several months later--when censorship was revealed to have a tragic cost (see below)--little was ever reported about the balloons, then or since.
As it happens, this is just what the balloons' designers originally intended.
The balloons were loaded with bombs, but their main purpose was to cause panic. Made primarily of paper and filled with hydrogen, they were designed to explode on impact and destroy all evidence of their existence in the process. Americans would be left with a raging forest fire--which would consume valuable timber stock and require precious manpower to control it--and no idea how it started. That was the plan, anyway.
What actually happened is that many of the balloons were lost at sea, and many of those that made it to North America failed to detonate upon impact. (Though they were supposed to be hair-trigger responsive, some inexplicably weren't; there's even a story of a sheriff who leapt after a low-flying balloon, caught it, and then hung on as it continued to sail across the landscape for quite a while.)
The sleuthing began soon after the balloons began arriving: where had they come from? There was little doubt that they were Japanese: little effort had been made to disguise their identity, since it was assumed they would explode. But U.S. authorities couldn't believe at first that they'd come all the way from Japan; their first guess (however improbable) was that they'd been launched from an internment or POW camp somewhere in the western U.S. It was only when government geologists later examined the sand used for ballast--a story well told in a January, 1996 New Yorker article by John McPhee--that they determined the balloons were coming from Japan.
Japan's military had been experimenting with the concept for years. The army and navy, in fact, had dueling prototypes--the navy's was made of rubberized silk, and the army's was paper. In the end, the army won out. Constructing the balloons required a vast workforce, spread across factories, classrooms, and even opera houses (a cavernous space was required to assemble the balloons).
The first balloon took off in November of 1944. Winter is a good season for flying from west to east, thanks to the jet stream, but not a great season for starting fires, since the forests are wet with rain and snow. Nevertheless, the Japanese pressed ahead with the program, sending more and more balloons aloft.
They anxiously awaited word of the destruction their balloons had wrought, but none came. The censorship ban in the United States held; lacking evidence that the balloons were reaching their targets, the Japanese military was forced to abandon the program.
Of course many balloons did reach their targets. Almost 300 landings were documented throughout Canada, Mexico, and the United States, including as far east as Farmington, Michigan--just 15 miles outside of Detroit, and about 6,400 miles from its launch site in Japan.
In the United States, diverse resources were deployed against the balloons. Planes regularly flew air patrols, and the 555th Parachute Infantry Battalion, or "Triple Nickels"--the nation's first all-black parachute infantry test platoon, company, and battalion--was deployed to parachute into Northwest forests and fight fires. (It was brutal duty: parachuting into heavily forested wilderness with little more than football helmets fitted with wire masks to protect them. Men broke arms, legs; some died.)
Curiously, one balloon came close to having a very large impact on the war. It was the only balloon to ever cause any property damage, and though the damage was slight, it could have been disastrous. In Washington state in March, 1945, a balloon sailed into power lines between Bonneville and Grand Coulee, which caused the power to fail at a top secret installation in Hanford. Fortunately, automatic safety mechanisms--previously untested--leapt into action, disaster was averted, and the plant soon went back to work, producing materials for the atomic bombs that would later be used against Japan.
In the spring of 1945, an Oregon reverend, Archie Mitchell, and his wife, Elsie, took some of the children from their church on a Sunday outing in the Gearheart Mountain area, sixty-some miles northeast of Klamath Falls, Oregon.
As they neared their destination, Rev. Mitchell pulled over and let the children out to go exploring while he parked the car. His wife got out as well to supervise. Moments later, with Rev. Mitchell just 40 feet away, the children started shouting excitedly about something they'd found. The reverend called out for them to be careful, but it was too late.
The children had discovered a Japanese balloon bomb. The blast killed the reverend's wife, who was pregnant, and four of the children immediately. One of the girls survived the blast, but only briefly; she died before anyone could get her to a hospital. The reverend was the sole survivor.
These six deaths--memorialized today by the Mitchell Recreation Area and monument near Bly, Oregon--were the only WWII casualties on the US mainland due to enemy causes.
Are there still bombs beneath the forest floors? Several have been discovered in the decades following the war, including one in 2014 in British Columbia. And the numbers indicate that it would still be wise to exercise caution when hiking or camping in less-traveled regions of the Pacific Northwest, where most of the balloons landed: only 300 or so balloons were ever documented as having reached North America, but close to 10,000 were launched--which leaves more than 90 percent of them unaccounted for still today.
While it's likely that most were lost at sea, it's not hard to imagine that some balloons, somewhere in the U.S. or Canada, remain to be found.