America is home to some of the greatest inventors and inventions in the world. Below is a timeline of some of our favorite inventions to come out of the USA.
1749 – Lightning rod
A lightning rod is one component in a lightning protection system. In addition to rods placed at regular intervals on the highest portions of a structure, a lightning protection system typically includes a rooftop network of conductors, multiple conductive paths from the roof to the ground, bonding connections to metallic objects within the structure and a grounding network. Individual lightning rods are sometimes called finials, air terminals or strike termination devices. In 1749 or 1750, the pointed lightning rod conductor, also called a “lightning attractor” or “Franklin rod”, is generally thought to have been conceived when Benjamin Franklin came to the conclusion that electricity and lightning were identical and of the same. By building lightning rods originally intended to be adorned atop church steeples, Franklin set about trying to prove their usefulness of shielding people and buildings from lightning. By 1752, Dr. Franklin tied the string of his “electrical kite” to an insulating silk ribbon for the knuckles of his hand. The kite in turn was attached to a metal key. During a storm, witnessed by his son William Franklin, Dr. Franklin had finally proven that lightning was a form of electricity when the metal key received an electrical charge from a bolt of lightning. Thus, the practical use of lightning rods, attributed to the inventor Benjamin Franklin, was confirmed.
1888 – Induction Motor
An induction motor is an AC electric motor in which the electric current in the rotor needed to produce torque is induced by electromagnetic induction from the magnetic field of the stator winding instead of using mechanical commutation (brushes) that caused sparking in earlier electric motors. They are also self-starting. The Serbian-American inventor Nikola Tesla explored the idea of using a rotating magnetic induction field principle, using it in his invention of a poly-phase induction motor using alternating current which he received a patent for on May 1, 1888. The rights to Tesla’s invention were licensed by George Westinghouse for the AC power system his company was developing.
The induction motor Tesla patented in the U.S. is considered to have been an independent invention since the Europe Italian physicist Galileo Ferraris published a paper on a rotating magnetic field based induction motor on 11 March 1888, almost two months before Tesla was granted his patent. A working model of the Ferraris inductionmotor may have been demonstrated at the University of Turin as early as 1885.
1892 – Internal combustion-powered tractor
A tractor is a distinctive farm vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanized. While steam powered tractors had been built earlier, In 1892, John Froelich invented and built the first gasoline-powered tractor in Clayton County, Iowa.
1901 – Assembly line
Used globally around the world, an assembly line is a manufacturing process in which interchangeable parts are added to a product in a sequential manner in order to create a finished product more quickly than with older methods. This type of manufacturing greatly reduces the amount of time taken to assemble a product, thus reducing production, material, and labor costs so that an affordable product cost can be passed onto consumers. According to a book entitled Michigan Yesterday & Today authored by Robert W. Domm, the assembly line and its basic concept is credited to Ransom Olds, who used it to build the first mass-produced automobile, the Oldsmobile Curved Dash. Olds patented the assembly line concept, which he put to work in his Olds Motor Vehicle Company factory in 1901. This development is often overshadowed by Henry Ford, who perfected the assembly line by installing driven conveyor belts that could produce a Model T in ninety-three minutes.
1903 – Airplane
A fixed-wing aircraft, or airplane, is a heavier-than-air craft whose lift is generated by air pressure differential between the upper and lower wing surfaces. The Wright brothers, Wilbur and Orville Wright of Dayton, Ohio, made the first powered and sustained airplane flights under control of the pilot in the Wright Flyer I on December 17, 1903 in Kitty Hawk, North Carolina. In the two years afterward, they developed their flying machine into the world’s first practical fixed-wing aircraft. By October 1905, the Wright Flyer III was capable and proven to circle in the air 30 times in 39 minutes for a total distance of 24.5 miles. The brothers’ fundamental breakthrough was their invention of “three-axis control”, which enabled the pilot to steer the aircraft effectively and to maintain its equilibrium. This required method has become standard on all fixed-wing aircraft. From the beginning of their aeronautical work, the Wright brothers focused on unlocking the secrets of control to conquer “the flying problem”, rather than on developing more powerful engines as some other experimenters did. Charles Edward Taylor built the first aircraft engine and was a vital contributor of mechanical aspects in the building and maintaining of early Wright engines and airplanes. Although there were many earlier attempts at heavier-than-air powered flight, some of which achieved successful short hops, and disputed earlier claims of sustained flight, the Wright brothers are officially credited by the Fédération Aéronautique Internationale, the international record-setting body for aeronautics and astronautics, as achieving “the first sustained and controlled heavier-than-air powered flight”. In addition, U.S. patent number #821393 for the airplane, was filed by Orville Wright on March 23, 1903 and was issued in May 1906.
1926 – Liquid-fuel rocket
The liquid-fuel rocket is a rocket with an engine that uses propellants in liquid form. On March 16, 1926 in Auburn, Massachusetts, Dr. Robert H. Goddard, the “father of modern rocketry”, launched the first liquid-fueled rocket in history, which used liquid oxygen and gasoline as propellants.
1947 – Transistor
In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. Because the controlled output power can be much larger than the controlling input power, the transistor provides amplification of a signal. The transistor is the fundamental building block of all modern electronic devices, and is used in radio, telephone, computer, and other electronic systems. From November 17, 1947 to December 23, 1947, John Bardeen and Walter Brattain at AT&T Bell Labs, underwent experimentations and finally observed that when two gold point contacts were applied to a crystal of germanium, a signal was produced whereby the output power was larger than the input. The manager of the Bell Labs semiconductor research group, William Shockley, saw the potential in this and worked over the next few months greatly expanding the knowledge of semiconductors in order to construct the first point-contact transistor. Shockley is considered by many to be the “father” of the transistor. Hence, in recognition of his work, the transistor is widely, yet not universally acknowledged as the most important invention of the entire 20th century since it forms today’s building blocks of processors found and used in almost every modern computing and electronics device. In recognition of their invention of the transistor, Shockley, Bardeen and Brattain were jointly awarded the 1956 Nobel Prize in Physics.
1971 – Personal Computer
The personal computer (PC) is any computer whose original sales price, size, and capabilities make it useful for individuals, and which is intended to be operated directly by an end user, with no intervening computer operator. The Kenbak-1 is officially credited by the Computer History Museum to be the world’s first personal computer which was invented in 1971 by John Blankenbaker. With a price tag of $750 and after selling only 40 machines, Kenbak Corporation closed its doors in 1973.
1973 – Mobile Phone
A mobile phone, or cell phone, is a long-range, electronic device used for mobile voice or data communication over a network of specialized base stations known as cell sites. Early mobile FM radio telephones were in use for many years, but since the number of radio frequencies were very limited in any area, the number of phone calls were also very limited. To solve this problem, there could be many small areas called cells which share the same frequencies. When users moved from one area to another while calling, the call would have to be switched over automatically without losing the call. In this system, a small number of radio frequencies could accommodate a huge number of calls. The first mobile call was made from a car phone in St. Louis, Missouri on June 17, 1946, but the system was impractical from what is considered a portable handset today. The equipment weighed 80 lbs, and the AT&T service, basically a massive party line, cost $30 per month plus 30 to 40 cents per local call. The basic network and supporting infrastructure of hexagonal cells used to support a mobile telephony system while remaining on the same channel were devised by Douglas H. Ring and W. Rae Young at AT&T Bell Labs in 1947. Finally in 1973, Martin Cooper invented the first handheld cellular/mobile phone. His first mobile phone call was made to Joel S. Engel in April 1973.
1983 – Internet
Not to be confused with a separate application known as the World wide web which was invented much later in the early 1990s (see article on the English inventor Tim Berners-Lee), the Internet is the global system of overall interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies. The concept of packet switching of a network was first explored by Paul Baran in the early 1960s, and the mathematical formulations behind packet switching were later devised by Leonard Kleinrock. On October 29, 1969, the world’s first electronic computer network, the ARPANET, was established between nodes at Leonard Kleinrock’s lab at UCLA and Douglas Engelbart’s lab at the Stanford Research Institute (now SRI International). Another milestone occurred in 1973 when Bob Kahn and Vinton Cerf co-invented Internet Protocol and Transmission Control Protocol while working on ARPANET at the United States Department of Defense. The first TCP/IP-wide area network was operational on January 1, 1983, when the United States’ National Science Foundation (NSF) constructed the university network backbone that would later become the NSFNet. This date is held as the “birth” of the Internet.
