2431
Joseph Saxton was a notable American inventor of the first half of the nineteenth century. He had built one of the first magnetoelectrical machines capable of producing electrical sparks.
Joseph Saxton was born in Huntington, PA, March 22, 1799; son of James and Hannah (nee Ashbaugh) Saxton. He attended elementary school until he was 12 years of age at which time he began working in his father’s nail factory. Saxton did not like factory work so apprenticed locally for two years in clockmaking and silversmithing. At this time he constructed a printing-press, and published a small newspaper at irregular intervals.
He moved to Philadelphia in 1818 to receive further training in horology and engraving. While working for the machinist Isaiah Lukens in Philadelphia, Saxton built a pyrometer with an optical lever for measuring the thermal expansion of metal that’s principle he would apply in several other designs, including the reflecting length comparator that he designed and built later working at the Office of Weight and Measures (OWM). Saxton worked in Philadelphia for two different shops before establishing his own engraving and watch making business. During this time he invented a machine for cutting the teeth of wheels, the outlines of which were true epicycloidal curves.
After 11 years of instrument making with distinction in Philadelphia where he received awards for his skill in clockmaking. With Isaiah Lukens he constructed an ingenious clock which gave the movements of the planets, and he also made the town clock placed in the belfry of Independence Hall, Philadelphia (shown left).
In his ambition to obtain knowledge he became a member of the Franklin institute, and acquired reputation among its members for his ingenuity. About 1828 he went to London to design, build, and market innovative instruments. There he became associated with the Adelaide Gallery of Practical Science, for which he constructed several mechanical toys. He there met Telford, Brunel, Whitwell, Hawkins and Faraday, through whose influence he was admitted to the meetings of the Royal institution.
In December 1832, he conceived the idea and committed his design to paper for a magnetoelectrical device. In June of 1833, he had built his first magnetoelectrical machine capable of producing painful sparks and shocks to his tongue. In June, 1833, he demonstrated before the British Association for the Advancement of Science in Cambridge, the workings of his magnetoelectric machine, capable of decomposing water and of producing brilliant electrical sparks and steady light by bringing charcoal points near together.
He then improved on this version of his magnetoelectrical machine by using a strong horseshoe magnet mounted horizontally with three fixed coils to a shaft rotating around a horizontal axis. Like Pixii, Saxton turned the shaft of his machine by a handle attached to a wheel. His machine was the first rotating coil machine to generate electricity of alternating current. By 1835, he had redesigned and built a magnetoelectrical machine that produced unidirectional (galvanic) pulsed current, strong shocks, and decomposed water.
During his residence in England Saxton invented a locomotive differential pulley, an apparatus for measuring the velocity of vessels; an air-gun with metallic cartridge; an apparatus for obtaining an electrical spark from the magnetism of the earth; another for measuring the velocity of electricity, and several useful articles. He also invented an automatic machine for measuring the height of the tides; he patented an ever-pointed pencil. He perfected the medal-ruling machine, invented by Gobercht of the U.S. mint.
Vernier calipers probably made by Joseph Saxton, ca. 1843-1873
Joseph Saxton was tendered the office of director of the printing machinery of the Bank of England, but declined this place in order to accept, in 1837, that of constructor and curator of the standard weighing apparatus of the United States mint in Philadelphia.
During his connection with the mint he constructed the large standard balances that are used in the annual inspection of the assays and the verification of standard weights. In 1843 he was given charge of the construction of the standard balances, weights, and measures to be presented to each of the states for insuring uniformity of measures in all parts of the country under the auspices of the Office of Weight and Measures (OWM) for United States coast survey (now the National Bureau of Standards). He invented an automatic instrument for recording the height of the tides, and applied the reflecting pyrometer that had been previously invented to the construction of measuring rods that would retain their length while subjected to different temperatures. A deep-sea thermometer and an immersed hydrometer were among his later inventions.
This instrument was built at the Office of Weights and Measures (OWM) from Joseph Saxton’s design. It was probably used first for comparing the yard end-standard that was part of the standard yard apparatus distributed by OWM to the states and custom-houses and, after 1866, for comparing meter end-standards. Saxton’s comparator could measure differences of 1 micrometer (1 millionth of a meter). It used a sensitive indicating mechanism, which was based on the rotation of a small mirror, to detect differences between the standard and the measuring rod being calibrated.
The mirror was mounted on a shaft which was coupled to a spring-loaded slide that rested against the end of the standard. Very small differences in rod length caused the mirror to rotate a small amount. These small rotations of the mirror were greatly amplified by sighting through a telescope where the image of a graduated scale was reflected into the telescope by the mirror. The instrument was used by first adjusting the rotating mirror so that the scale read zero when the standard was in place and then reading the difference, in micrometers, when the rod to be measured was replaced by the standard.
This dividing engine was built at the Office of Weights and Measures (OWM) from the design of Joseph Saxton. It was probably used to divide the two scales of the matrix that was part of the standard yard apparatus distributed by OWM to the states and custom-houses. This apparatus consisted of a brass yard end-standard, which fit between the jaws of a matrix consisting of two scales: a scale of 3 feet, with the first foot divided into inches and the first inch divided into tenths of an inch and a scale of tenths of a yard with the first tenth divided into hundredths of a yard.
Drawing of Standard Yard Distributed to States by Saxton.
Joseph Saxton made very early photos (daguerreotypes) in the U.S.A. The earliest surviving American daguerreotype is probably a view of Central High School in Philadelphia from the window of the US Mint in what is now Penn Square, taken by Joseph Saxton; sometimes dated September 25, 1839.
He was married in 1850 to Mary H. Abercrombie of Philadelphia, Pa.
Christian Schussele’s Men of Progress was described in 1862 as a painting of “the most distinguished inventors of this country, whose improvements … have changed the aspect of modern society, and caused the present age to be designated as an age of progress.” The nineteen men in the painting were brought together only in the artist’s imagination. They are (left to right): Dr. William Thomas Green Morton (surgical anesthesia), James Bogardus (cast-iron construction), Samuel Colt (revolving pistol), Cyrus Hall McCormick (mechanical reaper), Joseph Saxton (5th from left) (magnetoelectrical machines), Charles Goodyear (vulcanization of rubber), Peter Cooper (railway locomotive), Jordan Lawrence Mott (railway locomotive), Joseph Henry (electromagnet design), Eliphalet Nott (efficient heat conduction for stoves and steam engines), John Ericsson (armored turret warship), Frederick Sickels (steam-engine gear and steering device for ships), Samuel Finley Breese Morse (electric telegraph), Henry Burden (horseshoe manufacturing machine), Richard March Hoe (rotary press), Erastus Bigelow (power loom for carpets), Isaiah Jennings (threshing machine, repeating gun, friction match), Thomas Blanchard (irregular turning lathe), and Elias Howe (sewing machine). In the background appears a portrait of Benjamin Franklin, the patron saint of American science and invention.
Saxton made and patented many inventions during his life. Mr. Saxton received from the Franklin institute in 1834 the Scott legacy medal for his reflecting pyrometer. He was awarded a gold medal at the Crystal Palace fair, London, in 1851, for a nearly precise balance. In 1837 he was elected a member of the American philosophical society, mid in 1863 became a charter member of the National academy of sciences. A sketch of his life was contributed by Joseph Henry to the first volume of the “Biographical Memoirs” of the latter body (Washington, 1877).
He died in Washington, D.C., Oct. 26, 1873.
680