Cannon, Walter Bradford, 1871-1945, American physiologist. While still a medical student at Harvard, Cannon was the first to demonstrate (1897) that bismuth could be utilized as a contrast medium in the roentgenologic examination of the gastrointestinal tract. His interest in the physiological effects of emotional stimuli, especially on digestion, led to the publication in 1919 of Bodily Changes in Pain, Hunger, Fear and Rage. He later concentrated his attention on the adrenal glands and by 1929 was emphasizing the emergency function of these glands in meeting vital threats to the body and in maintaining the equilibrium of the many processes of the organism. In 1932, while professor of physiology at Harvard, he introduced the important concept of homeostasis.

Cannon, Joseph Gurney, 1836-1926, speaker of the U.S. House of Representatives (1903-11), b. Guilford co., N.C. A lawyer in Illinois, Cannon served as a Republican in Congress from 1873 to 1923, except for the years 1891-93 and 1913-15, when first the Populists and then the Progressives were able to defeat him. As speaker he carried the traditional power of his office to appoint all legislative committees to its ultimate arbitrary extremes, dictatorially ruling the House in the interest of his fellow "Old Guard" Republicans and suppressing minority groups. In Mar., 1910, insurgent Republicans, led by George W. Norris and supported by all the Democrats, passed a resolution that, by providing that the House itself should appoint the important Committee on Rules with the speaker ineligible for membership, broke Cannon's power.

Cannon, George Quayle, 1827-1901, Mormon apostle, b. Liverpool, England. He and his parents were converted to Mormonism in 1840; from the Isle of Man they emigrated to Nauvoo, Ill., in 1842, moving to Utah in 1847. In 1850, Cannon founded a Mormon mission in Hawaii. He became an apostle in 1859 and was assigned to England, where for four years he edited the Millennial Star and supervised missionary work. He served as a member of the Utah territorial council and as private secretary to Brigham Young, of whose will he was an executor. In 1867 he became editor of the influential Deseret News. Cannon was elected (1872) territorial delegate from Utah to Congress, but in 1882 he was refused his seat, under the Edmunds antipolygamy law. In 1888 he suffered imprisonment for practicing polygamy.

Cannon, Annie Jump, 1863-1941, American astronomer, b. Dover, Del. In 1897 she became an assistant in the Harvard College Observatory, where (1911-38) she was astronomer and curator of astronomical photographs. Recognizing that spectra of many stars had been photographed in the second half of the 19th cent., Cannon classified more than 500,000 stars, in the process publishing many papers on the subject. One of the most significant achievements in 20th-century astronomy and the basis for contemporary theoretical understanding of stellar evolution, the catalog, named after its patron Henry Draper, is still in use. In the course of her photographic work she discovered 300 variable stars, 5 novas, 1 spectroscopic binary, and many stars with bright lines or variable spectra. In 1896 she discovered SS Cygni, a "dwarf nova" that repeats its outbursts about every 60 days. She made a bibliography of variable stars that includes about 200,000 references. Each year the American Association of University Women presents the Annie J. Cannon Award for distinguished contributions to astronomy.

Long-range artillery piece, as distinguished from other big guns such as the howitzer or mortar. Early cannons, appearing in Europe in the 15th century, were smooth-bored and forged of iron, weighed 6,000–8,000 lbs (2,800–3,600 kg) and were loaded through the muzzle. They were mounted on wheeled carriages, which were thrown backward when the cannon was fired. Rifled bores and breechloading were adopted in the later 19th century, and new mechanisms such as the hydraulic buffer absorbed the recoil. Before 1850 ammunition was either cannister, grapeshot, or round, solid cannonballs and black powder, but rifled bores made possible the use of elongated projectiles, which had a longer range. The shrapnel shell was widely used in the 19th–20th century. Modern cannons, of high-grade steel, are towed on split-trail carriages or are mounted on tracked vehicles; a common calibre is 155 mm (6 in.). Many helicopters, airplanes, and naval vessels are equipped with multibarreled, Gatling-type rotary cannons firing 20-mm exploding shells.

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(born Oct. 19, 1871, Prairie du Chien, Wis., U.S.—died Oct. 1, 1945, Franklin, N.H.) U.S. neurologist and physiologist. He was the first to use X rays in physiological studies. He also investigated hemorrhagic and traumatic shock during World War I and worked on methods of blood storage. He researched the emergency functions of the sympathetic nervous system and homeostasis and sympathin, an epinephrine-like substance released by certain neurons. With Philip Bard he developed the Cannon-Bard theory, which proposed that emotional and physiological responses to external situations arise simultaneously and that both prepare the body to deal with the situation.

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(born May 7, 1836, Guilford county, N.C., U.S.—died Nov. 12, 1926, Danville, Ill.) U.S. politician. He began practicing law in Illinois in 1859. Elected to the U.S. House of Representatives in 1872, he served 46 years (1873–91, 1893–1913, 1915–23). A staunchly conservative Republican, he used his power as speaker (1903–11) in a partisan manner. In 1910 a coalition of Democrats and insurgent Republicans passed a resolution that made the speaker ineligible for membership on the rules committee, the main source of his power. Personally well liked, he was popularly known as “Uncle Joe.”

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