Milne, John

MILNE, JOHN

(b. Liverpool, England, 30 December 1850; d. Shide, Isle of Wight, England, 31 July 1913)

seismology.

The son of John Milne and Emma Twycross, Milne was educated at Liverpool and King’s College, London, and later studied geology and mineralogy at the Royal School of Mines. He was an ardent and adventurous traveler, starting, as a schoolboy and without parental leave, with a dangerous exploration of the Vatnajökull in Iceland. After early experience as a mining engineer in Great Britain and Germany he spent two years investigating the mineral resources of Newfoundland and Labrador, and later wrote geological notes on his observations in Egypt, Arabia, and Siberia. He visited Funk Island, off the coast of Newfoundland, where he made a large collection of skeletons of the great auk. In 1874 he served as geologist in an expedition that sought to fix the site of Mt. Sinai.

In 1875 Milne was appointed professor of geology and mining at the Imperial College of Engineering, Tokyo. The journey to Japan took eleven months, part of it crossing Mongolia by camel in sulvero weather. In Japan he turned to the study of earthquakes, the field in which he became world famous. He married Tone Noritsune, daughter of Horikawa Noritsune, the high priest of Hakodate. Milne retired from Japan in 1895 and went with his wife to Shide, on the Isle of Wight, where he continued in active seisniological work until his death after a short illness in 1913. Throughout his work at Shide he was assisted by the British Association for the Advancement of Science, which had established a seismological committee and appointed Milne its secretary. The work was a labor of love in which he had the devoted services of a Japanese assistant, Shinobu Hirota; many of the expenses were defrayed by Milne himself. He became a fellow of the Royal Society in 1887 and was awarded the Lyell Medal of the Geological Society of London in 1894 and a Royal Medal in 1908. The emperor of Japan conferred upon him the Order of the Rising Sun.

Milne was the most noted of a group of British scientists in Japan who pioneered modern seismology. An earthquake at Yokohama on 22 February 1880 led them, on Milne’s initiative, to form with their Japanese colleagues the Seismological Society of Japan, the first organization devoted exclusively to the study of earthquakes and volcanoes. Its work was crucial at a time when seismology was developing from a qualitative science, resting largely on geological observations and concerned with such matters as cataloging earthquake effects, into a science in which precise physical measurements are brought to bear. By 1892 Milne, in association with his colleagues J. A. Ewing and T. Gray, had developed a seismograph for recording horizontal components of the ground motion. It was reliable, compact, and simple enough to be installed on a worldwide basis and to provide a global coverage of ground movements due to large earthquakes. From that date the science of seismology as a branch of geophysics advanced apace, and seismological data began to be applied to unraveling the internal structure of the earth.

Milne’s researches touched on nearly all aspects of seismology. From his Tokyo records he deduced that in large earthquakes the ground accelerations can be comparable with the vertical acceleration of gravity. He showed that earthquake accelerations are in general greater—and therefore more dangerous—on soft ground than on hard rock. He initiated experiments to study properties of earthquake waves by generating artificial shocks by explosives and other means and by examining records of the ensuing ground motions. In this way he obtained records showing groups of waves corresponding to the P and S (primary and secondary) waves of modern seismology. He devised methods of locating distant earthquake sources from his records and evolved early travel-time curves of earthquake waves in terms of the distances from the source. He compiled important earthquake catalogs, including one covering the seismic history of Japan from 295 B.C. and another on destructive world earthquakes. (It is estimated that he examined about one hundred thousand documents in the course of this work.)

Starting in 1881, Milne produced the seismological General Reports of the British Association for the Advancement of Science. Subsequently, on the Isle of Wight, he produced the “Shide circulars,” which summarized the data gathered by a worldwide network of seismological stations set up by Milne and using his instruments. The Shide circulars were the forerunners of the International Seismological Summary, which, after Milne’s death, became the basic source of instrument-gathered data on earthquakes. With its recent successor, the Bulletin of the International Seismological Center, it has long been centrally important in world research on earthquakes.

Milne’s success was due to the combination of scientific brilliance and adaptability with a genial disposition and capacity to interest others in his enthusiasms. He was modest, notably hospitable, gifted with a sense of humor, and generous to others in his scientific and pecuniary help.

BIBLIOGRAPHY

I. Original Works. Milne was a prolific writer who contributed nearly 2,000 pages (about two-thirds of the entire content) of the Transactions and Journal of the Seismological Society of Japan during his editorship (1880–1895). He also published papers in the Proceedings of the Royal Society, Geological Magazine, and Bulletin of the Seismological Society of America. He wrote Earthquakes and Other Earth Movements (London, 1886); two eds. of a supp. volume, Seismology, appeared in 1898 and 1908. Among his noted publications are the Shide circulars and A Catalogue of Destructive Earthquakes, A.D. 7 to A.D. 1899 (London, 1912), published by the British Association.

II. Secondary Literature. A list of Milne’s publications is given by H. Woodward, in Geological Magazine, 9 (Aug. 1912), 337–346. For details of Milne’s life, see J.W.J., “Prof. John Milne, F.R.S.,” in Nature, 91 (Aug. 1913), 587–588; J.P., “John Milne, 1850–1913,” in Proceedings of the Royal Society, 84A (Mar. 1914), xxii–xxv; 91 (Aug. 1913), 587–588; and C. Davison, The Founders of Seismology (Cambridge, 1927), ch. 10. Milne’s Earthquakes and Other Earth Movements was revised by A. W. Lee (Philadelphia, 1939). For an account of Milne’s work at Shide, see Mrs. Lou Henry Hoover, “John Milne, Seismologist,” in Bulletin of the Seismological Society of America, 2 , no. 1 (Mar. 1912), 2–7.

K. E. Bullen