Early Mechanical Computers

Early Mechanical Computers

By Anthony Ha, Alex Lesperance, and Nadeem Shaik


    A computer is a general purpose device that can be programmed to carry out a finite set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem. We use computers almost everyday in our lives, especially being students or apart of the workforce. Sure we have the fastest internet available and we can read/research whatever we want to, or perform any operation we want, it all had to start somewhere. Where are those beginnings? The following is a few example of the earliest computers and they're functionality.

Jacquard's Programmable Loom

    Joseph Marie Charles (nicknamed "Jacquard" ) was a French weaver and merchant. Charles played a vital role in the "Jacquard Loom", one of the earliest programmable looms. This would lead to the development of other programmable machines, such as computers. Charles was the son of a silk weaver, and thus was tasked with restoring a loom, in 1790, created by Jacques de Vaucasan. Working on the automatic loom let to Charles developing a strong interest in the mechanization of silk manufacture. In 1801 he constructed a loom that used a series of punched cards to control the pattern of longitudinal warp threads depressed before each sideways passage of the shuttle. Charles later developed a machine where the punched cards were joined to form an endless loop that represented the program for the repeating pattern used for cloth and carpet designs. His invention allowed patters to be woven without intervention of the weaver. By 1812 there was about 11,000 Jacquard looms working in France, along with the machine starting to appear in other countries. By 1833 there were 100,000 power-looms being used.

Charles Babbage's Difference and Analytical Engine

    Charles Babbage was a very intelligent lad for his time. After switching schools many time due to illness, he became extremely interested in mathematics, which he taught himself. Babbage attended Cambridge and was the best mathematician around, yet failed to graduate with honors, ironically. In the time of Babbage there was a really high error rate in the calculation of math tables, so Babbage planned to find a solution to make it mechanical to remove the human error actor. His first shot at it was known as the Difference Engine. It was, theoretically, able to calculate polynomials by using a numerical method called the differences method. The government granted him a sum of money in 1823 to help with building it. Tragedy struck Babbage's life and halted work on the machine for a long period of time, during which Babbage traveled to clear his mind. After no progress being made on it and Babbage being unable to make it, the government officially abandoned the project in 1842. When Babbage was away from the difference engine, he began thinking of improved ways to make the engine, this one was called the Analytical Engine. The analytical engine used punched cards adapted from the Jacquard loom to specify input and the calculations to perform. The engine consisted of tow parts: the mill and the store. The mill, like a modern computer's CPU, executed the operations on values retrieved from the store, basically memory. The analytical engine was the world's first general-purpose computer. Between 1846 and 1849 Babbage started designing a second difference engine using the experience gained from the analytical engine. The machine used only a third of the part as the original. Unlike the analytical engine, Babbage made no attempt to modify the machine.


    The ENIAC (Electronic Numerical Integrator Analyzer and Computer) was a towering machine credited with starting the modern computer age. The ENIAC had 17468 vacuum tubes, 70000 resistors, 10000 capacitors, 1500 relays, and 6000 manual switches. Needless to say, it was a monument of engineering. Being such a massive machine it also took a huge amount of energy to run. The ENIAC was a byproduct of World War II because the military needed to develop firing tables for its artillery so the gunners in the field could quickly look up which settings to use with a particular weapon on a particular target under particular conditions. Equations were so complicated that it took a human days to calculate them, and a machine could speed up that process. It took about a year to design the ENIAC and 18 months to build it. When it was actually finished the war had been over for 3 months already. In a whole second the ENIAC would execute 5000 additions, 357 multiplications, and 38 divisions, a thousand times faster than anything before it. The only downside was that the programming was an absolute nightmare. It would take a team two days to reprogram the machine.

Gottfried Leibniz's Stepped Reckoner

    The great polymath Gottfried Leibniz was one of the first men who dreamed for alogical device. He tried to combine principles of arithmetic with the principles of logic and imagined the computer as something more of a calculator. He discovered that the computing processes can be done much easier with a binary number coding. Leibniz dreamed of inventing the general problem-solver, as well as a universal language. The impressive ideas and projects had to wait for centuries to actually be built, but he had the ideas from the very beginning. Starting to create the first prototype, Leibniz faced the same obstacles that other great minds had also faced, poor workmanship and the inability to create the fine mechanics required for the machine. Leibniz hired a skillful mechanician, the local clockmaker, to help him make the first metal prototype. It is unknown how many machines were actually manufactured by Leibniz. One of the machines was stored in the attic of a building of the University of Göttingen where it remained until 1879 when it was stumbled upon by a work crew when they were tasked with fixing a leak in the roof. At present time, there exists two old machines and several replicas.

Hollerith 1890 Census Tabulator

    The census tabulator was invented by an American statistician Herman Hollerith. It was created to help with, as the name suggests, tabulating the 1890 census. Hollerith originally created the machine in a contest held by the Census Bureau. The tabulator contains four main parts: the pantograph, card reader, tabulator dials, and sorting tables. The pantograph was how the Census Bureau transfered data from their surveys onto the punch cards to be read in. The card reader portion took the freshly punched cards from the pantograph and positioned it between to metal plates. The user would then press the plates together, whenever there was a spot with a hole a metal pin would pass through and connect with mercury on the other side completing the circuit and moving a counter dial forward. There were 40 dials that kept track of different information, gender, race and the like.

Wihelm Schickard's Clock

    Wilhelm Schickard is a German astronomer and mathematician who is credited with inventing the worlds first mechanical calculator. It was a fairly sophisticated device for its time. It could add, subtract, multiply and divide. The Clock could utilize six digit numbers and would ring a bell to announce overflow. The difference that Schickard's device and other calculating devices is that unlike other devices of its time which relied on a human operator to change different portions, his device was a state machine. In different situations, gears would be placed and interact with each other mechanically. It was also the first calculator that was active, meaning that each number inputed modified each other.

Works Cited

CharlesBabbage.net.  n.p.  n.d.  Web.  6 Oct. 2011.

Computing History.  The centre for Computing History, n.d.  Web.  6 Oct. 2011.

History-Computer.  The Stepped Reckoner of Gottfried Leibniz.
    n.p.  n.d.  Web.  6 Oct. 2011. 

PBS.  A Science Odyssey.  n.d.  Web.  6 Oct. 2011.

United States Census Bureau.  The Hollerith Machine, 22 Oct. 2011. 
    Web.  6 Oct. 2011.