|This Week in History
January 3 - 9, 1785 & 1793
Benj. Franklin and Friends Lay the Basis for Manned Flight
This new year, which will commemorate Benjamin Franklin's 300th birthday on Jan. 17, begins with the anniversaries of two events which ultimately contributed to the exploration of space. On Jan. 7, 1785 a manned balloon flight successfully crossed the English Channel from England to France, and on Jan. 9, 1793, the first American exhibition of manned lighter-than-air flight took place in Philadelphia.
The balloons, which were developed toward the end of the 18th Century, are often thought of nowadays as beautiful toysa pleasant concept, but a mere sidebar to aviation history. That is not the case, as Franklin himself knew. Sir Joseph Banks, a leading botanist and president of the British Royal Society from 1778 to 1820, had known Franklin in his London days, and corresponded with him in Paris. Although ostensibly a man of science, Banks looked at ballooning from a Newtonian worldview, and wrote to Franklin that, "I see an inclination in the more respectable part of the Royal Society to guard against the Ballomania [until] some experiment likely to prove beneficial either to society or science is proposed."
Franklin had told Banks that experimenting with balloons would someday "pave the way to some discoveries in natural philosophy of which at present we have no conception." He answered Banks' objection by writing that "It does not seem to me a good reason to decline prosecuting a new experiment which apparently increases the power of man over matter until we can see to what use that power may be applied. When we have learned to manage it, we may hope some time or other to find uses for it, as men have done for magnetism and electricity, of which the first experiments were mere matters of amusement." When a spectator at one of the early balloon launchings asked Franklin what this new invention could be used for, Franklin gave his famous answer: "What is the use of a new-born baby?"
Although scientists had been fascinated with the possibility of human flight at least since the time of ancient Greece, direct work on flying machines did not yield the desired results. The early days of aviation actually stemmed from research on the composition and properties of gases, one of those gases being the air itself. European scientific research had been badly disrupted during the Thirty Years War (1618-1648), but after the Treaty of Westphalia in 1648, coordination among scientists in the various European countries was resumed. When one of Ben Franklin's Boston mentors, Increase Mather, travelled to London in 1688 to try to maintain the independent charter of the Massachusetts Bay Colony, he met with many of the scientists working on the composition of gases. Over the period of his four-year stay, Mather saw Robert Boyle almost weekly, and attended many meetings of the Royal Society. He also probably talked with the leading scientist in the field, Christiaan Huygens, when he visited London during Mather's stay there.
Experiments with Gas and Electricity
During Franklin's lifetime, other researchers had taken up the work, and the composition of ordinary air was established. Many scientists worked with both gases and electricity, since the latter could be used to separate out the components of a gas or to combine two components to produce a third, as in the work of Henry Cavendish. Franklin had encouraged Joseph Priestly, an English minister, to make scientific experiments, and in 1767, Priestly authored, with Franklin's collaboration, the "History and Present State of Electricity." Priestly also experimented with gases, and in 1774 he produced what he called "dephlogisticated air," which later would be produced by French chemist Antoine Lavoisier and named "oxygen."
Lavoisier was a member of the French grouping which included Gaspard Monge, Lazare Carnot, and Claude Berthollet. This republican faction, also known as the "American faction," worked closely with Benjamin Franklin in supporting the American Revolution.
They also attempted to carry on the work of Jean Baptiste Colbert, the French statesman who had built up France's infrastructure through public works and expanded education. Lavoisier himself was responsible for initiating the building of canals, the establishment of savings banks, and the installation of street lighting in Paris. In June of 1783, Lavoisier published his research on the gas discovered by Henry Cavendish in England, and named it "hydrogen."
This research on gases came to the attention of Joseph and Jacques Montgolfier, two brothers who ran a paper manufactory near Lyons, France. Joseph had developed a strong interest in chemistry, and had set up a small laboratory. Jacques, an architect, had invented the first vellum paper. While working with samples of their paper, Joseph discovered that heated air inside a paper bag could lift it to the ceiling. The brothers collaborated for two years on their hot-air balloon project, and first conducted an unmanned flight from the market place of Annonay.
A regional assembly of deputies had been meeting in the town, and it sent word of the flight to Paris. The Marquis de Condorcet, head of the French Academy of Science, set up a committee to investigate the invention and to study possible improvements and uses. The aerostatic commission included Lavoisier, Monge, and Berthollet. While the Montgolfiers were preparing for a longer flight at Versailles in front of King Louis XVI and Queen Marie Antoinette, another scientist entered the lists. This was Jacques Charles, who had repeated all of Franklin's electrical experiments in order to confirm them, and was now using hydrogen gas in public demonstrations, forcing it through a tube to blow bubbles which would mount to the ceiling.
Charles determined to build a hydrogen balloon, and Benjamin Franklin contributed funds toward the project. Such a balloon was difficult to fill, because the hydrogen had to be produced by using iron filings and dilute sulfuric acid. Charles overcame the obstacles, and it required a thousand pounds of iron and half as many pounds of acid to produce enough hydrogen to fill his small balloon. On Aug. 27, 1783, from the Champ de Mars, the balloon was launched and flew 15 miles before it burst, due to the low pressure at high altitudes. Then, on Sept. 11, the Montgolfiers sent up a hot-air balloon at Versailles, with three passengers aboard: a sheep, a duck, and a rooster riding in a cage. The seven-minute flight was a success, and afterwards, all France talked of nothing else. On Nov. 21, the first aeronauts, a scientist named François de Rozier and a minor nobleman named François d'Arlandes, flew from the Bois de Boulogne in a Montgolfier balloon and covered five miles in 25 minutes. Franklin witnessed the flight, and was one of the scientists who signed the official certification of the history-making ascension when the Montgolfiers called on him at Passy on the following evening.
On Dec. 1, Jacques Charles and Noel Robert were launched in a hydrogen balloon from the Tuileries and quickly reached 2,000 feet. Franklin, suffering from gout, watched from his carriage. Charles had developed technological improvements, which included a valve to relieve internal pressure if the balloon rose too high, and ballast to toss overboard if the balloon fell too rapidly. Charles also took with him a thermometer and a mercury barometer, and when he made a second flight alone on the same day, he reached 9,000 feet in ten minutes. He demonstrated that an aeronaut could make meteorological observations at high altitudes, and his own calculations showed that the barometer had fallen by over nine inches, and the temperature dropped from 50 to 20 degrees Fahrenheit.
From the research on hydrogen balloons, came Charles's Law, also developed by Joseph Gay-Lussac slightly later, which states that if the pressure on a gas is constant, its volume is directly proportional to its temperature. Once Gay-Lussac had discovered this property of gases, he, too, became a balloonist, and in 1804, he ascended to more than 23,000 feet in order to test magnetism and the composition of the atmosphere at high altitudes.
By 1785, an aeronaut named Jean-Pierre Blanchard determined to cross the English Channel in a hydrogen balloon. In London, he met John Jeffries, a physician from a patriot family in Boston, who had taken a job as a physician to the Royal Navy, and had remained with the Crown during the Revolution. Jeffries financed the building of the balloon and their test flight over London carried experiments suggested by Henry Cavendish. The air samples gathered at various altitudes were subjected to chemical analysis, and the 12 observations of temperature, pressure, and humidity produced values which closely agree with modern measurements.
Then, on Jan. 7, 1785, Blanchard and Jeffries took off from Dover. Their crossing was fraught with difficulties, and the two passengers were forced to drop their ballast. Still flying too low, their food was jettisoned, followed by their aerial oars, rudder, a hand-cranked propeller, grapnels, rope, and then even their heavy outer clothes. Finally, just as they were about to climb onto the ropes in order to stay afloat as the balloon went into the water, a breeze drove them over the cliffs of Calais and they landed in France.
A few days later, they met with Louis XVI and then had dinner with Franklin at Passy. These two, and Franklin's grandson Temple, were the recipients of the first air-mail letters, sent from London in the balloon. Franklin wrote to James Bowdoin in Boston, that, "I sent to you some weeks since, by Mr. Gerry, Dr. Jeffries' account of his aerial voyage from England to France, which I received from him just before I left that country. My acquaintance with Dr. Jeffries began by his bringing me a letter in France, the first through the air, from England."
Eight years later, Blanchard, who had developed a prototype of the parachute, came to Philadelphia and New York to demonstrate balloon flight to the American public. Franklin had died in 1790, but President George Washington, Franklin's coadjutator in helping to develop the steamboat, attended the demonstration and provided Blanchard with a passport which instructed all Americans to give him aid when he landed. Blanchard took off from Philadelphia on Jan. 9, 1793, and landed 15 miles and 46 minutes later in Woodbury, New Jersey.
"Dunlap's American Daily Advertiser" described the crowd as "an immense concourse of spectators" which was notable for its awed silence when the balloon began to rise. "Indeed," said the newspaper, "the attention of the multitude was so absorbed, that it was a considerable time e'er silence was broke by the acclamations which succeeded."
By the time Blanchard visited America, Dr. Jeffries had already returned to Boston and resumed the practice of medicine. His son, John Jeffries, founded the Massachusetts Eye and Ear Infirmary. His grandson, Benjamin, also became an eminent opthalmologist, and lived until 1915, long enough to have the pleasure of learning about the Wright brothers' successful flight in an airplane, 118 years after his grandfather's perilous flight across the English Channel.