A Gallery of Electromagnetic Personalities 5...

Morse, Siemens, Kelvin

Samuel F.B. Morse (1791-1872), the son of a distinguished clergyman and geographer, mortified his parents when he pursued a career as an artist. He heard a conversation about the newly discovered electromagnet in 1832 aboard ship while returning from Europe. He conceived the electric telegraph and made the first working model in 1835. Morse had a lifelong career as a professor of art. One of his paintings recently sold for more than a million dollars.

Ernst Werner von Siemens (1816-1892) joined the Prussian artillery at seventeen to get the training in engineering that his family could not afford. While in prison for acting as a second in a duel he began chemistry experiments that led to his invention of the first electroplating system. In 1837 he saw an early telegraph and began inventing improvements, playing an important role in the development of early telegraphic systems. In 1888, Siemens was raised to the nobility and the "von" added to his name. His younger brother, Wilhelm, (later Sir William) was also a famous engineer who moved to England and founded the company which bears the family name. Oddly, it is not certain for which brother the unit of conductance is named.

William Thomson (Lord Kelvin) (1824-1907), son of a mathematics professor at the University of Glasgow, entered the University at age ten, published his first scientific paper when he was sixteen, and was named professor of physics at age twenty-two. He remained at Glasgow for fifty-three years. Thomson is most famous for his work in thermodynamics, but his theoretical analysis of cable transmission and his inventions (1854-1858) made the transatlantic cable possible and brought him great wealth and a knighthood. During the late 1860's he was involved in a famous controversy against the supporters of Darwin. In 1892 he was raised to the peerage.

Joule, Kirchhoff, Stokes

James Prescott Joule (1818-1889), born into a well-to-do family prominent in the brewery industry, studied at Manchester under Dalton. At age twenty-one he published the "I-squared-R" law which bears his name. Two years later, he published the first determination of the mechanical equivalent of heat. He became a collaborator with Thomson and they discovered that the temperature of an expanding gas falls. The "Joule-Thomson effect" was the basis for the large refrigeration plants constructed in the 19th century (but not used by the British brewery industry). Joule was a patient, methodical and devoted scientist; it became known that he had taken a thermometer with him on his honeymoon and spent time attempting to measure water temperature differences at the tops and bottoms of waterfalls.

Gustav Robert Kirchhoff (1824-1887), German physicist,announced the laws which allow calculation of the currents, voltages, and resistances of electrical networks in 1845 when he was only twenty-one. In further studies he demonstrated that current flows through a conductor at the speed of light. His other work established the technique of spectrum analysis which he applied to determine the composition of the Sun.

George Gabriel Stokes (1819-1903) was a British physicist and mathematician famous for a basic theorem of vector analysis. He worked on fluorescence and studied ultraviolet light. Stokes was the first to suggest the reason for the Fraunhofer lines but later disclaimed any prior discovery when Kirchhoff published the explanation. He was the first man since Newton to hold the three positions of Lucasian Professor at Cambridge, secretary, and then president of the Royal Society. Stokes, active in the Evangelical movement, was also president of the Victorian Society, founded to respond to Darwin's "Origin of Species". Stokes was knighted and created a baronet in 1889.