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On Thu, 25 Dec 2008 17:40:30 -0500, Boater
wrote: wrote: On Thu, 25 Dec 2008 10:28:16 -0500, Boater wrote: Eisboch wrote: "Boater" wrote in message ... Technology and innovation * David Bushnell (ca. 1776), inventor of the screw propeller, submarine, naval mine, and time bomb. Being boating related, I thought I'd mention that there are several claims to have "invented" the screw propeller. Bushnell isn't even mentioned at this site: http://www.irvineayrshire.org/propeller.htm Eisboch (Ho, ho, ho!) There's more than one way to screw. Here's a wiki entry: David Bushnell (1742 - 1824) of Saybrook, Connecticut, was an American inventor during the Revolutionary War. He is credited with creating the first submarine ever used in combat, while studying at Yale University in 1775. He called it the Turtle because of its look in the water. His idea of using water as ballast for submerging and raising his submarine is still in use today, as is the screw propeller, which was first used in the Turtle. While at Yale, he proved that gunpowder exploded under water. David Bushnell also made the first time bomb. With this, he also came up with mine barrage in 1777. He also invented the first time bomb. He combined his ideas in an attempt to attack British ships which were blockading New York Harbor in the summer of 1776 by boring through their hulls and implanting time bombs, but failed every time due to a metal lining in the ships hull to protect against parasites in their previous station, the Caribbean. David Bushnell then created the Turtle. The Turtle eventually sank. On June 8, 1781 he was promoted Captain of Sappers and Miners. Bushnell later traveled to France and then settled in Warrenton, Georgia where he taught at the Warrenton Academy and practiced medicine. He died in 1824, but before he died David was honored with a medal by George Washington. David Bushnell's Submarine Model is on display at the U.S. Navy Submarine Force Museum and Library in Groton, Connecticut. Another wiki: H James Watt of Scotland is generally credited with applying the first screw propeller to an engine, an early steam engine, beginning the use of an hydrodynamic screw for propulsion. Mechanical ship propulsion began with the steam ship. The first successful ship of this type is a matter of debate; candidate inventors of the 18th century include William Symington, the Marquis de Jouffroy, John Fitch and Robert Fulton, however William Symington's ship the Charlotte Dundas is regarded as the world's "first practical steamboat". Paddlewheels as the main motive source became standard on these early vessels (see Paddle steamer). Robert Fulton had tested, and rejected, the screw propeller. Sketch of hand-cranked vertical and horizontal screws used in Bushnell's Turtle, 1775 The screw (as opposed to paddlewheels) was introduced in the latter half of the 18th century. David Bushnell's invention of the submarine (Turtle) in 1775 used hand-powered screws for vertical and horizontal propulsion. The first screw propeller to be powered by a gasoline engine, fitted to a small boat (now known as a powerboat) was installed by Frederick Lanchester, also from Birmingham. This was tested in Oxford. The first 'real-world' use of a propeller was by David Bushnell, who used hand-powered screw propellers to navigate his submarine "Turtle" in 1776. The Bohemian engineer Josef Ressel designed and patented the first practicable screw propeller in 1827. Francis Pettit Smith tested a similar one in 1836. In 1839, John Ericsson introduced the screw propeller design onto a ship which then sailed over the Atlantic Ocean in 40 days. Mixed paddle and propeller designs were still being used at this time (vide the 1858 SS Great Eastern). In 1848 the British Admiralty held a tug of war contest between a propeller driven ship, Rattler, and a paddle wheel ship, Alecto. Rattler won, towing Alecto astern at 2.8 knots (5 km/h), but it was not until the early 20th century paddle propelled vessels were entirely superseded. The screw propeller replaced the paddles owing to its greater efficiency, compactness, less complex power transmission system, and reduced susceptibility to damage (especially in battle) Voith-Schneider propeller Initial designs owed much to the ordinary screw from which their name derived - early propellers consisted of only two blades and matched in profile the length of a single screw rotation. This design was common, but inventors endlessly experimented with different profiles and greater numbers of blades. The propeller screw design stabilized by the 1880s. In the early days of steam power for ships, when both paddle wheels and screws were in use, ships were often characterized by their type of propellers, leading to terms like screw steamer or screw sloop. I often anchor overnight off Charles Island, which is one of the areas where Bushnell did much of the testing during development of the Turtle. I am sure we have discussed this before, but...do you spend any time *on* the island? I'm sure there are empty beer cans there, buried just where we left them. The island is off limits to humans during the summer. They DO arrest anyone who tries to land there. They tried signs asking people to stay out of nesting areas, but dog owners didn't seem to care, and let their dogs run loose. That ruined it for everyone. At low tide, there is an isthmus from shore out to the island that is walkable without too much wading. There was some pretty convincing scientific research done on the island proving that "something" is buried pretty deep. They used the same equipment they used in the big dig to find underground viaducts, etc. What they located is thought to be part of Capt. Kidd's booty, as he was known to have stayed there many times. He stopped and cached portions of his treasure in several places heading up towards Newport. Although they know exactly where to dig, they were not able to get permits. |
#62
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#63
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On Dec 25, 9:57*am, Boater wrote:
Richard Casady wrote: On Wed, 24 Dec 2008 11:03:45 -0800 (PST), wrote: You should post a picture of your Yale degree, that would really impress people. If you had one. If I had a degree from Yale, I would keep quiet about. I would rather have a degree from Iowa State, which has a better engineering school. What kind of nuclear reactor do they have at Yale? How big is their particle accelerator? How is the vet school? Does Yale deal with anything of actual importance? I figure Yale English majors can drive cabs as well as those from anywhere else. I am not impressed with those who are particularly impressed with a Yale degree. Casady Loogy has an honorary degree from The Famous Nitwits School. Why do you say that, Bloater? Just because I won't for a minute believe your bull****? It can be settled easily. Oh, and speaking of nitwits, when you said "Most of the boys here who profess to be Christians are the worst-behaved assholes in the group, and that includes you, Herring, Florida Jim, Loogy, Jackoff, and a couple of others. But of course you don't think behavior has anything to do with Christianity. How convenient for you." I asked that you show where I EVER did such. Can you? I'd really like to see that, and I would apologize for doing such. |
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