Who Was Jacob Leupold? Biography, History, and Inventions

Some people learn to develop skills as an inventor, a scientist, a mathematician, or a mechanical engineer over years of schooling and training. Others are simply born with a natural knack for it. Jacob Leupold, a German-born instrument-maker with a lifelong passion for tinkering with mechanical things, is one such person. But what did his career consist of? And what is he known best for? Read on to learn more about this historic 17th and 18th-century figure.

Early life

Jacob Leupold was born on July 22nd, 1674, in Planitz, near Zwickau, Germany. His father, George Leupold, was a cabinet-maker, turner, sculptor, and watchmaker from Johanngeorgenstadt (Erzgebirge). His mother’s name was Magdalena Leupold. From an early age, Leupold had an immense interest in various mechanical things. This interest carried over into practically every venture in his adult life.

His father sent Jacob to Zwickau’s Latin school, and in 1693, Leupold started to study theology at the University of Jena. Through all this, Leupold did not give up his interest in mechanical things. Concurrent to his schooling, he was attending lectures by the well-known astronomer and mathematician Erhard Weigel. In 1694, Jacob left the University of Jena and switched to the University of Wittenberg, but soon left due to lack of funding.

Finally, in 1696, Jacob enrolled for free at the University of Leipzig. It was here that he apprenticed to an instrument maker and finally got to realize his dream of tinkering with mechanical things, just as he’d wanted to do since he was a child. In 1698, he started to produce globes, quadrants, sundials, and measuring and drawing instruments on the side while continuing his schooling. This side venture was so successful that he broke off his studies and set up a mechanical workshop. During this time, he was helping to design and build many instruments needed for experimental physics studies. It goes without saying that his academic interests had fully changed from that of a theologist to that of a mechanical engineer, scientist, and mathematician.

Career 

Hospital Warden

In 1701, despite his success as an instrument maker, Leupold got a position as a hospital warden at George Military Hospital. He had now obtained a regular income, but no longer had enough free time to dedicate himself to his instruments. Leupold became sick from an unknown illness in 1704, possibly a stroke. This significantly affected his memory and hearing. In 1714, he resigned from the hospital and returned to his instrument shop — this time with several assistants. While his work in the hospital was certainly noble, his greatest work as a mathematician, physicist, and mechanical engineer was still ahead of him

Mathematician, Physicist, and Instrument Maker

Now, at his own instrument shop, Leupold produced both musical and scientific instruments. During this time, he was also associated with the University of Leipzig as a mechanic. A year later, in 1715, he was appointed a member of the Berlin Academy of Sciences. This position quickly attracted two others: Commissioner of Mines to Saxony and Counsellor of Commerce to Prussia. In 1720, Leupold started to work on the manuscript of his encyclopedia Theatrium Machinarum, a nine-volume series on machine design and technology. It was published between 1724 and 1739 and was the first systematic analysis of mechanical engineering in the world. Leupold’s intended audience was not the highly educated scientist or mechanical engineer, but rather the common mechanic.

In 1727, not long after his death, the eighth volume of his encyclopedia was published. This volume, entitled Theatrum arithmetico-geometricum, was the best and most well-researched work on calculation, measurement, and invention published during the eighteenth century. It described and illustrated the calculating devices and machines of Kircher (Schott), Grillet, Leibnitz, and Poleni, along with Napier’s rods and several calculation tables. Interestingly enough, Leupold missed the Pascaline, the most famous calculating machine of the time.

This eighth volume also discussed and illustrated the various analog devices available at the time, including slide rules and sectors and other calculating and measuring rules (not to mention systems of computing using the fingers). In this volume, Leupold also mentioned that he had conceived an original calculating machine of his own.

While this calculating machine was never manufactured by Leupold, likely because of his early death, the principle of Leupold’s machine would later be used by Anton Braun. Braun designed a similar invention, but he didn’t manage to manufacture his machine, either. This was also due to an early death. Braun’s invention was finally manufactured by the mechanic Phillippe Vayringe in 1736.

What Is Jacob Leupold Known For? 

The Calculating Machine of Jacob Leupold

While Jacob Leupold never got the chance to make his calculating machine, there are still plans and outlines for the device that we can review. On this calculating machine, numbers were entered by means of six small digital wheels, each placed around the handle in the middle of the lid. Rotating this handle to a full revolution in a counterclockwise direction would transfer the input mechanism number to the six dials placed in the outer ring, each of which represented units, tens, hundreds, and so on. 

The machine’s result mechanism had nine positions on nine dials, each mounted on the outside ring of the invention. The dials had two parts—one for use during addition and multiplication, the other for use during subtraction and division. The result was indicated by a special pointer-arrow, which would rotate around the middle of the axes. On the inside of the same axes were 10-teeth stop-wheels fixed in place. They were capable of rotating in only one direction, clockwise, and could be fixed by the small rod and spring rod near the teeth.

Air Pump

In addition to his work on this early form of the calculator, Leupold is also credited as the inventor of the air pump. First designed in 1705, not much is known about Leupold’s early air pump except for the fact that he included it in his 1707 volume of Theatrum Machinarum and eventually sold the plans to the Prussian Academy of Sciences in 1711 at the advice of Gottfried Wilhelm Leibniz.

Jacob Leupold: Marriage, Children, and Personal Life

Marriage

In 1701, Jacob Leupold married Anna Elisabeth. While Anna would die just 13 years later, Leupold would outlive her by another 13 years on top of that.  

Children

Jacob and Anna had three sons and three daughters in their 13 years of marriage. Tragically, all but one died at a young age. 

Jacob Leupold: Published Works and Books

• Theatrum Machinarum (Volume 1)
• Theatrum Machinarum (Volume 2)
• Theatrum Machinarum (Volume 3)
• Theatrum Machinarum (Volume 4)
• Theatrum Machinarum (Volume 5)
• Theatrum Machinarum (Volume 6)
• Theatrum Machinarum (Volume 7)
• Theatrum Machinarum (Volume 8)
• Theatrum Machinarum (Volume 9)

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