Friday, March 12, 2010

Rufus Porter and the Dream of Flight

A few days ago, I stopped into the Friends of the Library Bookstore at the Sarasota Library.  I found a little book (51 pages) entitled, A Yankee Inventor's Flying Ship, which had been published in a very limited edition back in 1969.  In the book, the Minnesota Historical Society had re-published two pamphlets by Rufus Porter, which he originally published in 1849 and 1850.  I was intrigued to learn something about this man and his ideas.

People have yearned to fly for as long as they have watched the birds soaring in the breezes.  Leonardo da Vinci drew up a number of complex flying machine designs, although none of his concepts were ever built in his lifetime.  Recently (2005), a hang-glider he designed was constructed to his original specifications and it actually worked - although it was not very stable compared to modern designs.

Long before winged aircraft, balloons were the first vehicles used for manned flight.   In 1783, the Montgolfier Brothers developed hot-air balloons that were used for the first tethered and free-floating flights with people on board.  Almost immediately, there was a competing technology:  hydrogen-filled balloons.  The first successful human flight in a hydrogen balloon took place in December of 1783, only a couple of months after the Montgolfiers' flights.

Balloons suddenly sprang forth in the public's imagination and balloon images and designs became all the rage.  Of course, the early balloons had no propulsion or steering - you went where the winds carried you.  By 1784, the French Robert Brothers imagined an oblong-shaped dirigible.  They built and flew a prototype but the oars used for propulsion and direction were useless.

Let's fast-forward to America in 1834:  An itinerant dance teacher and interior mural painter named Rufus Porter (1792 - 1884) came up with his own idea for a hydrogen-filled airship.  Power would be provided by a steam engine coupled to a spiral-shaped propeller assembly.  Porter's design was immense.  He envisioned an airship 500 feet long and 50 feet in diameter that would be capable of carrying a hundred passengers at 50 miles per hour.

Porter developed small models of his ideas and went on a long and mostly fruitless search for investors to fund a full-scale prototype.  But Porter was not a crackpot.  Although not trained as an engineer, he used accurate and extensive calculations to help guide his designs.  He was very informed about the inventions of his day.  In fact, he was the founder of the Scientific American in 1845 (he sold the periodical about 18 months later to focus on his flying machines).  He was also the creator of almost thirty other inventions.

By 1847, Porter had demonstrated a small working model of his airship in New York and two years later he founded the Aerial Navigation Company.  Not coincidentally, 1849 was the year of the California Gold Rush and people were looking for any means possible to get to the gold fields quickly. Porter saw a promotional opportunity and made the most of it. By now, he had scaled up his designs for an airship to one that was 800 feet in length and capable (he claimed) of transporting 50 to 100 people across the country at 100 miles per hour, thus making the trip from New York to California in only three days.

Note the tongue-in-cheek Currier lithograph (Ives was not yet a partner) from 1849 that shows several fanciful ways to get to the Gold Rush including Porter's airship in the upper left-hand corner.

Porter published his first and longest pamphlet in 1849, describing his ideas and using it as a stock prospectus in his attempt to raise funds.

Not surprisingly, Porter had few takers for his airship business but modern analyses of his designs show that while he did not understand aerodynamics (no one did in those days), his insights into lift, low-drag profiles, and structural designs were far ahead of his time.  Unlike earlier dirigibles, Porter's airship had an internal frame that gave it strength and rigidity.  Later, successful rigid airship designs used the same principles.

In 1850, Porter managed to almost complete an airship 240 feet in length but it was destroyed by a tornado shortly before completion.  His second attempt soon thereafter was a 700 foot long model but rowdy crowds destroyed the hydrogen gas bag before it could be launched.  He made a third and final attempt in 1854 but this one also ended in failure.

Porter's designs were grandiose, especially for his day.  The German Zeplin, Hindenburg, built in the early 1930's was the same 800 feet in length that Porter had proposed.  Goodyear Blimps are only 192 feet long.  The illustration below gives you a better idea of the relative sizes.  The Hindenburg is on the top, Porter's airship is in the middle, and the Goodyear blimp is on the bottom - all to scale.

Porter never gave up on his ideas.  He was still attempting to put together enough funding to build a prototype as late as 1869 when he was 77 years old.  Porter died in 1884, never having seen his airship idea succeed.  But he did leave a legacy.  First, of course, is the Scientific American, now the pre-eminent science publication for informed lay audiences.  He also invented more than just his airships.  He is said to have invented the idea for the rotating component of the handgun which made Colt's revolver possible.  Colt paid him $100 for his patent.  But Porter has also left a legacy of murals painted on walls of inns and old homes throughout New England which are now appreciated to be masterpieces of this type of art.

Rufus Porter is another great example of the 19th Century Renaissance Man that I blogged about recently.  I love his versatility.  I love his enthusiasm.  I love his tenacity.  I wish he could have known the thrill of flying.

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