Inventions That Change The World

Chappe pioneers a long-range, rapid, visual signaling system. In Paris in 1791, a little-known engineer and inventor named Claude Chappe (1763-1805) began to experiment with an optical signaling system or visual telegraph. His ambition was to send complex messages via a succession of towers using a combination of signaling arms. Three years later, in 1794, working with the aid of his four brothers, Chappe demonstrated his first optical semaphore. His string of fifteen towers placed within sight of each other was able to transmit a message 120 miles (190 km) from Paris to Lille in only nine minutes. The project's burdensome costs were borne by a French leadership who were recently at war with Austria and eager for any strategic advantage in communication.      Each tower was topped by a 30-foot (9 m) mast to which a rotating arm was attached with smaller, counterbalanced wooden arms at its ends. These could move through the horizontal and vertical and in a series of seven 45-d

Larrey introduces the medical-car vehicle. Ambulance first began to appear on the Napoleonic battlefields of France in 1792. Their inventor, surgeon Dominique-Jean Larrey (1766-1842), had grown frustrated with regulations requiring him to stay to the rear. After observing how the mobility of the French artillery helped it to quickly disengage from an advancing enemy, Larrey proposed to the military hierarchy what he called ambulance val-ante, or "flying ambulance", that would follow the artillery into battle and tend to the wounded where they fell.      Larrey devised a horse-drawn wheeled carriage with a central compartment able to transport two patients comfortably on leather-covered horsehair mattresses; windows on either side provided good ventilation. Inside, patients could be moved in and out easily on floors set on rollers. Recessed areas contained medicines and medical equipment, and ramps at the rear doubled as emergency operating tables. “Before… the fl

The French initiate metric measurement in 1791. In the nineteenth century there was a confusing multiplicity of units of measurement. In England, for example, length was measured in inches, feet, yards, furlongs, rods, chains, poles, perches, miles, and more.      In 1791 the French National Assembly instructed the Academy of Sciences to design a simple decimal system. In 1973 the unit of length, the meter, was chosen to be one ten-millionth of the distance between the north pole of Earth and the equator, the specific meridian that chosen being the one that passes though Paris. Unfortunately, the length of the meridian had not been measured at the time nd this job was carried out by Jean- Baptiste-Joseph Delabmbre (1749-1822) and Pierre Mèchain (1744-1804).      A platinum bar engraved with two marks separated by the new "meter" was then placed in the International Bureau of Weights and Measures in Paris. Decimal divisions,such as the centimeter and kilometer were then

Guillotine proposes a machine for humane decapitation.       In 1789, at the start of the French Revolution, Joseph-Ignace Guillotine (1738-1814), a medical doctor of progressive views, proposed a thorough-going reform of the French penal system. Inspired by the humane and rational principles of the Enlightenment, Guillotin's proposals included in single method of execution to replace the massy horrors of breaking on the wheel and hanging by the neck. Guillotin's mechanism would prevent suffering, while making  capital punishment more democratic; beheading was traditionally the punishment reserved for aristocrats-an efficient decapitation machine would spread that privilege to all classes.       In 1791 the French National Assembly appointed a committee to push the project through. Although Guillotin was involved, the prime mover was Dr. Antoine Louis, Royal Physician and Secretary of the Academy of Surgery. The basic design adopted, with a blade hauled to the top of a high