include the decimal angle measurement, making much of de Prony's work worthless. This also meant that the funding needed for de Prony to finish and publish his tables dried up. De Prony continued his work until 1800, but because his publisher went bankrupt, the work was not seen by the public eye until the first excerpt of the table was published a century later. The Napoleonic government abandoned the project, before abandoning the metric system entirely in 1812 dooming de Prony's work. Prony's brake One of de Prony's important scientific inventions was the "brake" which he invented in 1821 to measure the torque produced by an engine. He also was first to propose using a reversible pendulum to measure gravity, which was independently invented in 1817 by Henry Kater and became known as the Kater's pendulum. Prony's estimation method Prony created a method of converting sinusoidal and exponential curves into a systems of linear equations. Prony estimation is used extensively in signal processing and finite element modelling of non linear materials. Engineering projects Prony was employed by Napoleon to superintend the engineering operations for protecting the province of Ferrara against the inundations of the Po and for draining and improving the Pontine Marshes. After the Restoration he was likewise engaged in regulating the course of the Rhône, and in several other important works. Distinctions Prony was a member, and eventually president, of the French Academy of Science. He was also elected a foreign member of the Royal Swedish Academy of Sciences in 1810. His name is one of the 72 names inscribed on the Eiffel Tower. A street, Rue de Prony, in the 17th arrondissement of Paris is named after him. See also Prony equation Charles Storer Storrow References Notes Citations External links Prony Estimation 1755 births 1839 deaths People from Rhône (department) Barons of the First French Empire Members of the Chamber of Peers of the July Monarchy French engineers Members of the Royal Swedish Academy of Sciences Officers of the French Academy of Sciences Foreign Members of the Royal Society 18th-century French mathematicians 19th-century French mathematicians Commandeurs of the Légion d'honneur Burials at Père Lachaise Cemetery