gin—the wire hooks. Some say the plantation foreman suggested to Greene that the wooden teeth be replaced by wires, and that Greene then told Whitney. Whitney’s supporters, on the other hand, cite a letter to the editor of Southern Agriculturist magazine, admittedly based on shaky sources, that Whitney specifically asked Mrs. Greene for a pin to use at the start of his experimentation. A factor tending to swing the pendulum toward Whitney was that, before he left Massachusetts, he was the new country’s only hatpin manufacturer.
In 1794, Whitney filed a patent application for his (or Greene’s) cotton gin. He also gave a demonstration of his model to a few friends, producing in 1 hour a full day’s output of several workers. The witnesses to this demonstration immediately had whole fields planted in green seed cotton. Word spread, and the farmers grew excited and impatient. Whitney’s shop was broken into, and examinations made of his new cotton gin. Then, more fields were planted with cotton.
Before Whitney had a chance to prepare a patent model of his invention (required in those days), or to secure patent protection, the cotton crops were ready for harvest, and the planters did not have time to work within ethical or legal parameters. Whitney’s cotton gin was simply pirated. Whitney and his partner, Phineas Miller, decided to build cotton gins and lease, not sell, them to the planters in exchange for 1 pound of every 3 pounds of cotton put through their machines. The planters revolted at this arrangement, as a virtual flood of white cotton was erupting from the Southern soil.
The partners, heavily in debt, were forced to approach the Southern courts to enforce their patent rights, which resulted in disaster. In 1801, they opted for grants from several Southern states, and, in return, the cotton gin would become public property. One state, South Carolina, accepted, offered $50,000, made a down payment of $20,000, and never paid the remainder. Eventually, Whitney and Miller received about $90,000 from the states, which was used up immediately to pay legal costs and other expenses. In 1803, the states repudiated their agreements, and sued Whitney for the return of the money paid previously. In 1804, Whitney petitioned the U.S. Congress for relief, and by one vote avoided financial ruin. At that point, he felt the past 10 years were wasted. Whitney became discouraged with cotton, and left the South forever.
Upon returning to New Haven, Connecticut, he started manufacturing goods and developing mass production techniques and factories. In time, his manufacturing process developments changed the industrial capabilities of the North, just as his cotton gin had changed the face of the South.
INVENTORS AND INVENTIONS
Charles Babbage
THE DIFFERENCE ENGINE
Charles Babbage was a man of many talents. However, completing projects he started was not one of them. This essay will skip over many of the accomplishments of Mr. Babbage in his lifetime, and go straight to the point where he became known as a computing pioneer. Babbage, an Englishman, is credited with developing the first mechanical computers. However, his models were never completed, largely because of economic problems, and possibly clashes of personality, particularly with the Astronomer Royal of England.
Babbage directed the construction of early steam‐powered calculating machines that achieved modest success, but those machines also suggested that the calculations could be mechanized. He received British government funding for his calculation mechanism project for over 10 years, but eventually the treasury in England lost faith in him, and stopped funding his project. The machines that Babbage did manage to prototype were mechanical, and their basic architecture was similar to a modern computer. For example, the program memory and the data memory were separated, operation was based on instructions, the control unit could make conditional jumps, and his devices had a separate input/output unit.
In Babbage’s time, printed mathematical tables were calculated by humans. As you might expect, errors were constantly known to occur in the transcription of such calculations. Babbage at one time prepared his own account of how he began thinking about mechanical mathematical computations to replace those that were made by hand. In his own words, he stated that, in 1812, he was in his room in the Analytical Society, reviewing a table of logarithms, which he concluded was full of mistakes. He then had the thought of computing all tabular functions by machinery. He knew that the French government had previously produced several tables by a new method, where several French mathematicians decided how to compute the tables, six more divided the operations into simple stages, and the work itself, which was merely addition and subtraction, was performed by 80 human “computers” who knew only those two arithmetical processes. Babbage considered that this was mass production applied to arithmetic, and became enthralled by the concept that the labors of unskilled human computers could be taken over completely by faster and more reliable machinery.
In about 1819, Babbage’s interests were turning to astronomical instruments, and his ideas became more precise. He conceived of a plan to construct tables using the method of differences by mechanical means. He began to construct a small prototype “difference engine” in 1819, which he completed by 1822. He described his invention in a paper published on June 14, 1822, by the Royal Astronomical Society of England, titled “Note on the Application of Machinery to the Computation of Astronomical and Mathematical Tables.” At the time the paper was written, Babbage had also thought about a machine that could print the results of the difference engine, but this printer was not completed at the time his paper was written. An assistant of Babbage’s was required to write down the results obtained by the difference engine by calculating successive terms of the sequence n2 + n + 41. Babbage urged that a larger difference engine could do the work undertaken by many people, saving costs and being totally accurate. However, such a larger machine was never built during his lifetime.
Babbage’s difference engine was designed to compute values of polynomial functions. The calculations were supposed to be done automatically by using the method of finite differences, which made it possible to avoid the need for multiplication and division. In his 1822 paper, he described a machine using the decimal number system that was powered by cranking a handle. Babbage worked with Joseph Clement on the prototype of his design for a difference engine in 1823. In 1831, the collaboration between Babbage and Clement ended over arguments involving money. The prototype that Babbage and Clement did construct evolved into the first difference engine, but remained unfinished. This prototype was approximately one‐seventh of the calculating section of the difference engine that Babbage initially envisioned. Even though Babbage’s design was feasible, the metalworking techniques of the early 1800s could not economically produce the needed parts in the quantity and to the precision required. The design of the first difference engine would have included, had it been completed, around 25,000 parts, weighed 15 tons, and would have been 8 feet tall. Babbage received ample initial government funding for the project; however, the device was never completed.
A difference engine can be defined as an automatic mechanical calculator designed to tabulate polynomial functions. The name derives from the method of divided differences, a way to interpolate or tabulate functions by using a small set of polynomial coefficients. Most mathematical functions commonly used by engineers, including logarithmic and trigonometric functions, can be approximated by polynomials, allowing a difference engine to compute several useful tables of numbers. The difficulty in producing an error‐free table by teams of mathematicians or human computers was the driving force behind Charles Babbage’s desire to build a mechanical device to automate the calculating process.
In 1827, the costs of constructing Difference Engine No. 1 were becoming astronomical, and work stopped on the project in 1834. Up to that time, the British government had invested £17,000 into the project, and Babbage had invested £6,000 of his own funds. From 1834 to 1842, the British government did not make a decision on whether to continue to support Babbage in his projects,