A propeller is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral, that when rotated performs an action, similar to Archimedes' screw. It transforms rotational power into linear thrust by acting upon a working fluid such as water or air; the rotational motion of the blades is converted into thrust by creating a pressure difference between the two surfaces. A given mass of working fluid is accelerated in one direction and the craft moves in the opposite direction. Propeller dynamics, like those of aircraft wings, can be modelled by Bernoulli's principle and Newton's third law. Most marine propellers are screw propellers with helical blades rotating around an horizontal axis or propeller shaft; the principle employed in using a screw propeller is used in sculling. It is part of the skill of propelling a Venetian gondola but was used in a less refined way in other parts of Europe and elsewhere. For example, propelling a canoe with a single paddle using a "pitch stroke" or side slipping a canoe with a "scull" involves a similar technique.

In China, called "lu", was used by the 3rd century AD. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at the effective angle; the innovation introduced with the screw propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a single blade, but in practice there are nearly always more than one so as to balance the forces involved; the origin of the screw propeller starts with Archimedes, who used a screw to lift water for irrigation and bailing boats, so famously that it became known as Archimedes' screw. It was an application of spiral movement in space to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. Leonardo da Vinci adopted the principle to drive his theoretical helicopter, sketches of which involved a large canvas screw overhead. In 1661, Toogood and Hays proposed using screws for waterjet propulsion, though not as a propeller.

Robert Hooke in 1681 designed a horizontal watermill, remarkably similar to the Kirsten-Boeing vertical axis propeller designed two and a half centuries in 1928. In 1693 a Frenchman by the name of Du Quet invented a screw propeller, tried in 1693 but abandoned. In 1752, the Academie des Sciences in Paris granted Burnelli a prize for a design of a propeller-wheel. At about the same time, the French mathematician Alexis-Jean-Pierre Paucton, suggested a water propulsion system based on the Archimedean screw. In 1771, steam-engine inventor James Watt in a private letter suggested using "spiral oars" to propel boats, although he did not use them with his steam engines, or implement the idea. One of the first practical and applied uses of a propeller was on a submarine dubbed Turtle, designed in New Haven, Connecticut, in 1775 by Yale student and inventor David Bushnell, with the help of the clock maker and brass foundryman Isaac Doolittle, with Bushnell's brother Ezra Bushnell and ship's carpenter and clock maker Phineas Pratt constructing the hull in Saybrook, Connecticut.

On the night of September 6, 1776, Sergeant Ezra Lee piloted Turtle in an attack on HMS Eagle in New York Harbor. Turtle has the distinction of being the first submarine used in battle. Bushnell described the propeller in an October 1787 letter to Thomas Jefferson: "An oar formed upon the principle of the screw was fixed in the forepart of the vessel its axis entered the vessel and being turned one way rowed the vessel forward but being turned the other way rowed it backward, it was made to be turned by the hand or foot." The brass propeller, like all the brass and moving parts on Turtle, was crafted by the "ingenious mechanic" Issac Doolittle of New Haven. In 1785, Joseph Bramah in England proposed a propeller solution of a rod going through the underwater aft of a boat attached to a bladed propeller, though he never built it. In 1802, Edward Shorter proposed using a similar propeller attached to a rod angled down temporarily deployed from the deck above the waterline and thus requiring no water seal, intended only to assist becalmed sailing vessels.

He tested it on the transport ship Doncaster in Gibraltar and at Malta, achieving a speed of 1.5 mph. In 1802, the American lawyer and inventor John Stevens built a 25-foot boat with a rotary stem engine coupled to a four-bladed propeller; the craft achieved a speed of 4 mph, but Stevens abandoned propellers due to the inherent danger in using the high-pressure steam engines. His subsequent vessels were paddle-wheeled boats. By 1827, Czech-Austrian inventor Josef Ressel had invented a screw propeller which had multiple blades fastened around a conical base, he had tested his propeller in February 1826 on a small ship, manually driven. He was successful in using his bronze screw propeller on an adapted steamboat, his ship, Civetta of 48 gross register tons, reached a speed of about 6 knots. This was the first ship driven by an Archimedes screw-type propeller. After a new steam engine had an accident his experiments were banned by the Austro-Hungarian police as dangerous. Josef Ressel was at the time a forestry inspector for the Austrian Empire.

But before this he received an Austro-Hungarian patent for his propeller. He died in 1857; this new method of propulsion was an improvement over the paddlewheel as it was not so affected by either ship motions or changes in draft as the vessel burned coal. John Patch, a mariner in Yarmout

Kali is an IPX network emulator for DOS and Windows, enabling legacy multiplayer games to work over a modern TCP/IP network such as the Internet. Versions of the software functioned as a server browser for games that natively supported TCP/IP. Versions were created for OS2 and Mac, but neither version was well polished. Today, Kali's network is still operational but development has ceased. Kali features an Internet Game Browser for TCP/IP native games, a buddy system, a chat system, supports 400+ games including Doom 3, many of the Command & Conquer games, the Mechwarrior 2 series, Unreal Tournament 2004, Battlefield Vietnam, Counter-Strike: Condition Zero, Master of Orion II; the Kali software has a time-based cap for unregistered versions. For a one-time $20 fee the time restriction is removed; the original MS-DOS version of Kali was created by Scott Coleman, Alex Markovich and Jay Cotton in the spring of 1995. It was the successor to a program called iDOOM that Cotton wrote so he could play id Software's DOS game DOOM over the Internet.

After the release of Descent, Coleman and Cotton wrote a new program to allow Descent, or any other game which supported LAN play using the IPX protocol, to be played over the Internet. In the summer of 1995, Coleman went off to work for Interplay Productions, Markovich left the project and Cotton formed a new company, Kali Inc. to develop and market Kali. Cotton and his team developed all subsequent versions. Kali appealed only to hardcore computer tinkerers, due to the difficulty of getting TCP/IP running on MS-DOS. Kali95 took advantage of the greater network support of Windows 95, allowing Kali to achieve mainstream popularity. In the mid-1990s, it was an popular way to play Command & Conquer, Warcraft II: Tides of Darkness, Duke Nukem 3D, other games over the Internet, with more than 50,000 users worldwide by the end of 1996; the fact that only a small one-time fee was charged for the service, rather than a monthly subscription contributed to its popularity. This was possible due to Kali's scaled-down services.

Since it was the only way for Windows and DOS users to play Warcraft II: Tides of Darkness against people outside of a LAN or dial-up connection, Blizzard included a copy of the program on the CD, going so far as to provide a customized executable which optimized the game's network code to account for Internet latency and allowed users to specify their own settings for packet transmission and handling. During the height of IPX emulation's popularity, a competing product called "Kahn" was being sold by the now-defunct developer Stargate Networks for $15. However, Kali was well-established by this point; the minor cost savings proved ineffective against Kali, Kahn never achieved much market share. The market for Kali dried up as games began to host their own online services, such as battle.net, MSN Gaming Zone, through direct TCP/IP connections, made easier by Microsoft's DirectPlay package. As IPX itself was phased out, Kali's unique emulation technology fell by the wayside and the software shifted its emphasis to becoming a game browser, a market where strong competitors such as GameSpy were established.

In the early 2000s, Cotton decided to sell Kali to a company that would have the capital to expand the program. However, this move proved to be disastrous for Kali as the new company folded shortly after the purchase. A year Cotton reacquired the rights to the Kali software and system. Since he has resumed development and support of Kali; as of 2009, the latest version of Kali is 2.613, released in February 2004. At present Kali works with over 400 games. Support has faded over the last years making usage of Kali less effective. Kali has gained new life, because the IPX protocol has been removed in all version of Windows after XP. Occasional specials reduce the cost of Kali to $10; as of 2014, the software has for the most part died. However, there is still a loyal following that uses the software as a chat room. Games, such as Descent, are still played among this group of gamers. Kali won Computer Gaming World's 1996 "Special Award for Online-Enabling Technology"; the editors called it "perhaps the most significant milestone so far in the nascent online gaming industry."

It won Computer Games Strategy Plus's award for the best online service of 1996, beating Mpath and the T. E. N. service. Next Generation named it number one on their "Top 10 Online Gaming Sites" in early 1997, citing the lack of subscription fees and the unsurpassed selection of games supported. Official site

Sheldon Lettich is an American screenwriter, film director and producer. He is best known for his collaborations with Jean-Claude Van Damme and his work in the action film genre, he was born in New York City, but moved to California at a young age and grew up in the Los Angeles area. After graduation from high school he spent nearly four years in the U. S. Marine Corps, serving as a radio operator in South Vietnam with 3rd Battalion, 1st Marines, with the elite 1st Force Reconnaissance Company based at Camp Pendleton, California, he worked his way through college as a professional photographer, attended the AFI Conservatory's Center for Advanced Film Studies as a Cinematography Fellow. Although his initial career goal was to become a director of photography, at the AFI his interests branched out to encompass writing and directing, which became the two fields where he found eventual success in the entertainment business. Based upon his experiences in Vietnam, he co-authored the renowned play Tracers with a group of Vietnam vets who were aspiring actors.

First performed July 4, 1980 at the Odyssey Theater in Los Angeles, the play traveled to Joseph Papp's Public Theater in New York City, the Steppenwolf Theater in Chicago, the Royal Court Theater in London, numerous venues worldwide. It received both Drama Desk Awards and L. A. Drama Critics Awards, is still being performed throughout the world. Around the same time, Lettich was writing numerous spec screenplays. One of these, co-written with Josh Becker, subsequently became the cult classic, Thou Shalt Not Kill... Except, which starred Bruce Campbell, directed by Becker, both frequent collaborators of Sam Raimi, his screenplays began attracting the attention of producers in Hollywood. He co-authored the Cold War drama, the first starring role for a young Joaquin Phoenix. Around the same time he wrote the screenplay for the now-classic martial arts film, which launched the career of Jean-Claude Van Damme. One of his Vietnam-based screenplays caught the eye of Sylvester Stallone, which resulted in an overall deal with Stallone's White Eagle Productions, led to him co-writing Rambo III with Stallone.

The success of Bloodsport not only turned Jean-Claude Van Damme into an international action star, but it forged a long and ongoing friendship with the man who wrote it. Van Damme helped to launch Lettich's directing career with the film, which became Van Damme's first movie to be released theatrically by a major U. S. studio. This was followed by Double Impact, filmed in Hong Kong, with Lettich directing Van Damme in a challenging double role as twin brothers seeking revenge for their parents' murder. Lettich next discovered Mark Dacascos, who made his starring debut in Only the Strong, a film that introduced the Brazilian martial art of Capoeira to international audiences, he directed Dolph Lundgren in The Last Patrol, Daniel Bernhardt in Perfect Target. Continuing his long association with Van Damme, Lettich was a writer and a producer on the historical French Foreign Legion film, filmed on location in Morocco, and he directed The Order, an action-thriller starring Van Damme and Charlton Heston, filmed on locations in Israel and Bulgaria.

His most recent directorial effort, which he co-wrote, is The Hard Corps, an urban action-romance. Starring Jean-Claude Van Damme and Vivica Fox, the film was shot on locations around Vancouver, British Columbia, on sound stages in Romania, was financed and released worldwide by Sony Pictures Entertainment, he has always wanted to make a Vietnam War movie he wrote, but after seeing Tropic Thunder he felt that no one would take a Vietnam war movie anymore. Firefight Thou Shalt Not Kill... Except Bloodsport Rambo III Lionheart Double Impact Only the Strong Perfect Target Legionnaire The Last Patrol The Order The Hard Corps Black Rose Max Double Impact 2 Official website Sheldon Lettich on IMDb

Percival Charles Lindsay was an Australian landscape painter and cartoonist, born in Creswick, Victoria. Percy was the first child born to Dr Robert Charles Lindsay, his siblings included the well-known artists: Sir Lionel Lindsay, Norman Lindsay, Ruby Lindsay and Sir Daryl Lindsay. Percy first further developed his skills during the late 1880s. Tuition from Fred Sheldon and Walter Withers saw him develop his painting skills to a professional level. Lindsay worked as an illustrator and cartoonist. During his time in Melbourne, he was at the centre of the city's bohemian art community. In 1918 he moved with his wife and child to Sydney, where he continued to paint landscapes while working as a cartoonist on The Bulletin magazine. Percy is the least known of the five Lindsay artists and is best remembered for his fine landscape paintings and his happy carefree personality; the artist had a retrospective exhibition of his work at the Ballarat Fine Art Gallery in 1975. An accompanying essay by the BFAG director Ron Radford was included in the exhibition catalogue.

A biography on the artist was published by Australian Scholarly Publishing in 2011. Alan McCulloch,'Encyclopedia of Australian Art', Richmond 1968. Ron Radford,'Percy Lindsay', Ballarat Fine Art Gallery, Ballarat, 1975. Silas Clifford-Smith,'Percy Lindsay: Artist & Bohemian', Australian Scholarly Publishing, Melbourne, 2011. Silas Clifford-Smith. "Lindsay, Percy". Dictionary of Sydney. Dictionary of Sydney Trust. Retrieved 9 October 2015. Creswick - A Living History: The Lindsay Family

David Oliver was an American stage and television actor. Oliver was one of eight children born to William Oliver in Concord, California, he began his acting career in 1982. From 1983 to 1985, Oliver played the role of Perry Hutchins on the daytime soap opera Another World. In 1986 he played the role of Sam Gardner in the miniseries A Year in the Life; the miniseries became a regular series in the fall of 1987 on NBC for one season. Oliver's wife in both the miniseries and regular series was played by Sarah Jessica Parker, he starred in several stage roles including the San Diego Civic Light Opera's productions of The Unsinkable Molly Brown and Li'l Abner. Oliver was one of the founding members of Young Artists United. Shortly before his death, he had a role in the play Elegies staged at the Canon Theater in Beverly Hills. On November 12, 1992, Oliver died at his Los Angeles home of complications due to AIDS, he was survived by his parents, seven siblings, his partner, Terry Houlihan. His memorial service was held on November 18 at Forest Lawn Memorial Park in the Hollywood Hills.

David Oliver on IMDb

There is a New Zealand horse of the year in each of the racing codes: - Standardbred or harness racing, either pacers or trotters, - Thoroughbred racing or gallopers. The New Zealand Harness Horse of the Year award is awarded to the Standardbred horse, voted to be the champion horse within a New Zealand racing season; this award is open to all racehorses racing within New Zealand, regardless of sex. Overseas performances are now included; the New Zealand Champion Racehorse of the Year is awarded to the Thoroughbred horse, voted to be the best racehorse within a New Zealand racing season. This award is open to all racehorses racing within New Zealand, regardless of sex. Overseas performances are now included. Thoroughbred racing in New Zealand Harness racing in New Zealand List of leading Thoroughbred racehorses List of millionaire racehorses in Australia