Even craft-based military technologies were not generally produced by military funding. Instead, craftsmen and inventors developed weapons and military tools independently and actively sought the interest of military patrons afterward. Following the rise of engineering as a profession in the 18th century, governments and military leaders did try to harness the methods of both science and engineering for more specific ends, but frequently without success. In the decades leading up to the French Revolution, French artillery officers were often trained as engineers, and military leaders from this mathematical tradition attempted to transform the process of weapons manufacture from a craft-based enterprise to an organized and standardized system based on engineering principles and interchangeable parts (pre-dating the work of Eli Whitney in the U.S.). During the Revolution, even natural scientists participated directly, attempting to create “weapons more powerful than any we possess” to aid the cause of the new French Republic, though there were no means for the revolutionary army to fund such work. Each of these efforts, however, was ultimately unsuccessful in producing militarily useful results. A slightly different outcome came from the longitude prize of the 18th century, offered by the British government for an accurate method of determining a ship's longitude at sea (essential for the safe navigation of the powerful British navy): intended to promote—and financially reward—a scientific solution, it was instead won by a scientific outsider, the clockmaker John Harrison. However, the naval utility of astronomy did help increase the number of capable astronomers and focus research on developing more powerful and versatile instruments.