The Jet Stream Gets Drafted

Balloons in WWII: Japan's (not so) cunning plan

Where is the prince who can afford to so cover his country with troops for its defence as that ten thousand men descending from the clouds might not in many places do an infinite deal of mischief before a force could be brought together to repel them?

-Benjamin Franklin, upon witnessing the first manned balloon flight


on the U.S.
in WW2

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In 1783, the Montgolfier brothers, Etienne and Joseph, flew the first balloon. They had been fascinated with flight; some months earlier Joseph had dropped a sheep equipped with a parachute from the roof of his father's barn.[1] The brothers filled a large balloon with smoke from a hot-burning straw fire, watched it float up a bit, drift a mile or so, and sink back down. Etienne and Joseph were an immediate sensation. Shortly thereafter they sent up a rooster, a sheep, and a duck, and, other than a nasty wound incurred by the rooster when the sheep trod on it, the passengers landed unscathed.[2]

About the same time, Jacques Alexandre Cesar Charles filled a rubberized balloon with hydrogen with the same purpose in mind. To generate the amount he needed, he had to dissolve 1,000 pounds of iron with 500 pounds of sulphuric acid over three days.[3] In Lighter Than Air: An Illustrated History of the Airship, Lee Payne describes the scene:

Finally, on August 27, 1783, in the Champ de Mars before a crowd of fifty thousand cheering Parisians that filled the streets and rooftops, Charles's balloon rose to a height of three thousand feet and drifted out of sight. It came to earth fifteen miles away near the village of Gonesse, where the peasants, recognizing a work of the devil, tore it to shreds with pitchforks.

These advances were quickly put to more utilitarian ends. In 1848, the citizens of Venice tossed out the occupying Austrians, and proclaimed a Venetian Republic. Predictably, this didn't sit well with the Austrians, and they returned in force to make mischief but encountered difficulty. In particular, Austrian Lieutenant Uchtaius looked about Venice and saw that, for the purposes of laying siege to the city, the topography was wanting: he had trouble placing big guns in a position to properly shell the Italians. Instead, the Lieutenant imagined that lightweight hot air balloons constructed of paper could loft a payload of ordnance into the city. Such balloons were crafted and carried 33 pounds of explosives, set with a half-hour time fuse, and troops scurried around with them to launch them into the proper wind currents. In Japan's World War II Balloon Bomb Attacks on North America, Robert C. Mikesh details the project's efficacy:

No great material damage was done to the enemy, though one of the charges burst in St. Mark's Square. An unexpected shift of the wind drove some of the balloons back to the besiegers and their use was abandoned.

Such was the early military career of the balloon.[4] Most scientists went about designing zeppelins soon afterward and occupied themselves with the task of powering the craft in a chosen direction. Before settling on propellers, they mucked about with oars, trained birds, and cannons shot backward. Meanwhile, the lowly, unpowered balloon was not thought to be effective for military use. However, in 1933, undeterred by the lessons of history, the Japanese Military Scientific Laboratory began to experiment with balloons. This was done alongside such projects as a remote-controlled, unmanned tank and a lethal variant of today's high-voltage stun guns. Payloads from bombs or propaganda leaflets to actual troops were considered for balloons, but the project was shelved, along with other, kookier ones, until about ten years later. While the designs gathered dust, World War II began, and Japan mounted a very effective sneak attack on the United States by bombing Pearl Harbor in Hawaii one early morning.

Still Smarting, United States Stages Counterattack

Under cover of night, the United States Navy held a little bomb run of its own over mainland Japan on April 18, 1942, a few short months after the Pearl Harbor attack. An aircraft carrier headed towards Japan, where it intended to deploy the bombers from roughly 500 miles offshore. The run, commandeered by one Lt. Col. Jimmy Doolittle, consisted of only sixteen planes, but this was the first attack on mainland Japan by the U.S. and was meant as revenge for Pearl Harbor. Some 800 miles out, the carrier was sighted by a Japanese patrol boat, and, after sinking the boat, the bombers took off early. This risked running out of fuel following the raid, but premature takeoff was deemed necessary in order to cut down the response to the warning likely radioed by the patrol boat. Payloads delivered but gas tanks empty, the airmen wound up bailing out, mostly over Japanese-controlled areas of China. The Chinese, no great lovers of the Japanese at this point in time, hid the Americans and smuggled most of them to safety. Doolittle himself, humiliated at the loss of all of his planes, expected a court martial, but given the national morale boost his raid spurred (it was the first United States military success against the Japanese), was instead awarded the Medal of Honor.

While material destruction sustained by Tokyo in the Doolittle raid was limited, the psychological damage sustained by the Japanese people was immeasurable. It suggested their mainland was vulnerable to attack, and, piddly vacation islands in the Pacific notwithstanding, their enemies to the east were untouchable. No practical airfields existed for the Japanese to retaliate from, and despite some tries at launching bombers from submarines or flying one-way aircraft, attacks on the U.S. mainland remained impossible.

Kooky Idea Given Reconsideration

About this time, Japanese meteorologists had been studying "rivers of fast moving air" in the upper atmosphere, today better known as jet streams. At around 30,000 feet, a healthy one shoots over Japan, across the Pacific, and bumps into North America.

In the winter of 1943-44, when the Japanese released some 200 balloons equipped with measurement devices and radio transmitters into the jet stream to better characterize it, they figured it might actually be possible to fly balloons from the Japanese mainland all the way to the west coast of the United States.

Hydrogen-filled balloons[5] like theirs, however, would run into problems: to float a balloon from Japan to the U.S. takes about 60 hours, and during that time either the sun will heat the hydrogen enough to pop the balloon, or the cool night will sink it. To get around this problem, they built a little valve on the balloon to vent gas when it got too high, and they put several sandbags on the basket that got dropped when the balloon got too low. Over 60 hours, the balloon vented during the day and dropped sandbags at night to maintain that important 30,000 foot altitude (if it got lower, the winds slowed down and it would likely be stranded over the ocean). Said balloons also carried a nasty bomb and a couple of incendiary charges, the better to start forest fires in the Pacific Northwest with.

The balloons themselves were made out of a kind of paper derived from the kozo bush (washi paper) that was produced in little squares and pasted together by schoolchildren. The children were collected in vast concert halls and sumo wrestling amphitheatres,[6] stripped of their potentially damaging hairpins and long fingernails, and instructed to glue together the washi squares with konnyaku-nori, paste made from a Japanese potato commonly known as "Devil's Tongue". Wartime being what it was, workers were frequently scolded for eating the paste.[7] The balloons were assembled (about 10 m in diameter), and, from November 1944 through March 1945 (when Japanese scientists determined the jet stream was most amenable to transcontinental travel) some 10,000 of them were set aloft from Japan's eastern shores.

Believe It

They worked. Not that well, but they did. Fragments of 285 balloons have since been found all over North America; the majority turned up in Washington and Oregon but some made it as far south as Mexico, as far north as Alaska, and as far east as Michigan.[8] People saw them silently sliding by, or were startled to hear loud explosions and fire issuing from nowhere. Unfortunately for the Japanese, the jet stream was most cooperative during the wet season [9] of the Pacific Northwest, so the balloons weren't very effective in the forest fire department. The U.S. stationed firefighters just in case, and requested those in agricultural circles to be on the lookout for strange diseases in livestock (at this point, it was anticipated that the Japanese might use the balloons for the dispersal of germ warfare materials). In early January, 1945, Newsweek and the New York Times ran articles on these mystery balloons before the nation's press received a curt note from the Office of Censorship requesting a moratorium on such stories.

When the U.S. first heard about the balloon bombs, it was not believed. After a few were found things changed. They were considered a threat and they outlined it well in an unpublished manual called BD-1. Even though balloons which dropped incendiary or antipersonnel were found, other uses were enumerated in order of importance:

1. Bacteriological or chemical warfare or both

Japan Used Germ Warefare -- In 1939, the Japanese military poisoned Soviet water sources with intestinal typhoid bacteria at the former Mongolian border. In Oct.1940, Japan tested germ warefare on 3 villages in China with a "plague bomb" containing infected mosquitos that carried the black death, killing hundreds.They had planned to drop the bomb on San Diego, but the U.S. unleashed the atomic bomb several months before Japan had the chance.

During an infamous biowarfare attack in 1941, the Japanese Military released an estimated 150 million plague-infected fleas from airplanes over villages in China and Manchuria, resulting in several plague outbreaks in those villages. Reportedly, by 1945, the Japanese program had stockpiled 400 kilograms of anthrax to be used in a specially designed fragmentation bomb.

In the only known use of biowarfare by Germany, a large reservoir in Bohemia was poisoned with sewage, in 1945.

2. Transportation of incendiary and antipersonnel bombs.
3. Experiments for unknown purposes.
4. Psychological efforts to inspire terror and diversion of forces.
5. Transportation of agents.
6. Anti-aircraft devices.

After some months of media silence while balloons continued to rain (okay, piddle) on the continental United States, one Reverend Archie Mitchell, his wife Elsie, and five children were picnicking in the woods outside of Bly, Oregon when the woman and children happened upon a downed balloon. One of the group tugged on it, and the bomb detonated, killing all of them. The Office of Censorship quickly yanked its decree, and everyone else got warned not to touch strange objects in the woods.

Meantime, the United States military forces were all running willy-nilly trying to figure out what was happening. Planes were dispatched to shoot down incoming balloons, but they proved difficult to find, and less than twenty were destroyed this way. To test whether the balloons could be detected by radar, they reinflated some downed ones. Mikesh details one such episode:

Moored to a winch attached to a truck, the balloon ascended to approximately 1,000 feet and after about an hour fell limp to the ground because of helium loss through the now weathered and porous paper... [some attempts later] the balloon rose to approximately 4,500 feet and remained airborne for about thirty minutes before it finally settled into some trees about five and one-half miles away, damaged beyond repair. [10]

U.S. Asks, How'd They Get Here?

After finding some radio transmitters in a minority of balloons, the U.S. went about looking for transmissions from ones still aloft, and, lo and behold, determined the balloons were actually coming from the direction of Japan proper. Transcontinental delivery of balloons was thought impossible; everyone believed that the balloons were either being released by submarines, by Japanese frogmen on shore, or perhaps German POW camps inside U.S. borders, yet the transmissions issued from out in the Pacific. While the radio signals were being investigated, a few of the sandbag ballasts from the balloons were sent to the U.S. Geological Survey's Military Geology Unit, which was supposed to be in the know about sand.


1. Sadly, the sheep's fate is unknown.

2. Contemporary scientists had speculated that the atmosphere might not be breathable above a few hundred feet.

3. Dissolving certain metals with sulfuric acid liberates hydrogen gas.

4. The Austrians retook Venice in 1849, largely by starving them out.

5. Hot air doesn't have nearly the lift hydrogen does. The Japanese balloons were designed to carry about 1,000 pounds. A comparable hot air balloon would be absurdly large. Additionally, the fuel regulation required to keep the air hot would prove technically difficult.

6. Nichigeki Music Hall and Kokugi-Kan Wrestling Hall in Tokyo were used, for example

7. Some of the schoolchildren have since grown and provided accounts of balloon construction, not the least of which, one by United States Air Force club manager Yoshiji "Eddie" Ohsawa, appears in the USAF publication Airman. The article, subtitled, During WWII he fought us; now he feeds us details his childhood. We sniggered at the subtitle.

8. The 285 discovered have been in mostly populous areas: it is quite conceivable that there are additional balloons in rural areas that still await discovery.

9. For the areas most hit, precipitation hovers somewhere between 8 and 12 inches a month, and measurable (>.01 inch) rain on about half the days. Better luck next time.

10. Mikesh


1. John McPhee. Irons in the Fire. Farrar, Straus, and Giroux, 1997.

2. National Park Foundation. The Complete Guide to America's National Parks, 1990-1991 Edition. Simon & Schuster, 1990. [Out of Print]

3. Lee Payne. Lighter Than Air: An Illustrated History of the Airship A.S. Barnes and Co., 1977.

4. Robert C. Mikesh. "Japan's World War II Balloon Bomb Attacks on North America". Smithsonian Annals of Flight, 9. 1973.

5. John McPhee. "The Gravel Page". The New Yorker, 1. January 29, 1996

Balloons: The Winds of Fortune

Japan's failed WW2 balloon attack on the US

The USGS: FDR's Whipping Boy

Heretofore, the U.S. Geological Survey had been little more than a Federal burp. In particular, the dinky agency led a rocky existence in the 1930s, due in no small part to a disagreement it had with President Franklin Roosevelt. FDR happened to hold great stock in the restorative properties of the water of Warm Springs, Georgia, after a visit there ameliorated his polio in the early 1920s, and, when in a position of authority, made it his business to figure out how that water worked. He asked the Survey what the story was, and it calmly replied that the water at Warm Springs, Georgia was no different than ordinary tap water.

This lack of faith annoyed FDR to no end. He felt a miracle had occurred on the occasion of his visit, and was unwilling to chalk it up to the placebo effect. Once President, Roosevelt sent a full team of geologists there. Upon arrival, the Survey team encountered another team headed by German Doktor Paul Härtle. Doktor Härtle was a bubbly miracle water expert hailing from Bad Kissingen, Germany who was there to check on them at the President's behest; Roosevelt apparently didn't trust his own geologists. The U.S. Geological Survey team, headed by Foster Hewett, had a chat with Härtle. In his account, "The Gravel Page", John McPhee details the conversation:

At one point, Doktor Härtle asked Hewett, "Are you studying the gas that comes from the water?"
Hewett answered, "We are."
Härtle said, "Have you examined the shape of the bubbles?"
Hewett's pupils doubled in size. He said, "No, we haven't."
Härtle said, "Oh, you must examine the bubbles. Some bubbles are round, but others are square."
Hewett (all this would appear in U.S. Geological Survey Bulletin 1589) said, "Do I understand that you know places in Germany where the bubbles issuing from water are square?"
"Oh, yes, Mr. Hewett," Härtle said. "The bubbles of gas at Bad Kissingen are square. You see, Mr. Hewett, when you put your arm in water that contains gas, bubbles appear on the flesh. Now if these bubbles are round they produce no effect, but if they are square they have the effect of stimulating nerves on the skin. It is extremely important that you determine whether these bubbles are round or square."

Hewett spent two and a half years studying Warm Springs, and concluded that the magic fluids were "ordinary rain water without exceptional physical or chemical properties." After this information was printed in his report, a bound copy was sent to the White House. It was not acknowledged. [1]

A contemporary geologist with the Survey later commented,

There was a period of about six years in the thirties when no one was hired by the Survey. Roosevelt wanted to believe the German, who said the bubbles came up in the water and the corners scratched your skin. That was just bullshit. [2]

But Then Uncle Sam Came Crawling Back

Despite this low social standing, during World War II, the Survey found itself once again needed. The War Department wanted to know soil conditions for landings. Were they marshy? How about quicksand? Where do we deploy our troops? These questions needed answering, geologists were ably suited to answer them, and the Survey's budget and roster swelled. Before tracking balloon radio signals, the War Department handed the Survey a pinch of the sand it had found from balloon wreckage, and asked the geologists to determine its origin. The War Department fully anticipated the Survey to find that the sand had origins in California somewhere; the military figured the balloons had been launched surreptitiously by invading agents stationed on the continent.

Wrong, said the Survey. In the sand they found certain skeletons of tiny critters -- diatoms -- of a type only found near Asia. [3] Put that together with an absence of coral, the presence of certain volcanic products, and the Survey guessed two possible locations: one was the very site of deployment, and the other a little off, perhaps one hundred miles from two other sites. These locations were swiftly bombed, and two of the three hydrogen plants supplying the balloon effort were destroyed.

Destroyed, Yes, But Pretty Much Finished Anyway

By then, the balloon operation itself had been largely halted. The Japanese military, faced with the news blackout, had no reason to suspect that the balloons were doing any damage. While the local propagandists told of a United States engulfed in flames, the higher-ups remained sceptical. The media ban by the United States Office of Censorship was far and away the best defence against the bombs. The balloon project was expensive and had been considered a great waste of money and effort by the Japanese military despite being the world's first successful transcontinental attack and the most effective of any of Japan's war efforts against the mainland U.S. As McPhee tells us, the damage sustained by other attacks was even more modest:

In February of 1942, Japanese Submarine I-17 shelled an oil field up the beach from Santa Barbara, and damaged a pump house. In June, Submarine I-25 shelled a coastal fort in Oregon, damaging a baseball backstop. [4]

Compared to these, the balloon effort was a rousing success. It was also a metaphorical one:

On March 10, 1945, a paper balloon that had crossed the Pacific Ocean, the Olympic Mountains and the Cascade Range descended in the vicinity of the Manhattan Project's production site at Hanford, Washington. The balloon landed on an electric line that fed power to the building containing the reactor that was producing the Nagasaki plutonium, and shut the reactor down. [5]


1. McPhee
2. McPhee
3. Diatoms themselves are everywhere, but frequently have distinctive shapes, making types and origin discernible.
4. McPhee
5. McPhee


1. John McPhee. Irons in the Fire. Farrar, Straus, and Giroux, 1997.

2. National Park Foundation. The Complete Guide to America's National Parks, 1990-1991 Edition. Simon & Schuster, 1990. [Out of Print]

3. Lee Payne. Lighter Than Air: An Illustrated History of the Airship. A.S. Barnes and Co., 1977.

4. Robert C. Mikesh. "Japan's World War II Balloon Bomb Attacks on North America". Smithsonian Annals of Flight, 9. 1973.

5. John McPhee. "The Gravel Page". The New Yorker, 1. January 29, 1996. p.52-60