He was educated at Marlborough and abroad, being destined for the diplomatic service; but he joined Frank Benson's Shake- spearean company in 1893 and made his first professional appear- ance in London a year later with J. L. Toole in Barrie's Walker, London. He married the actress Mabel Hackney, and with his wife played in Brieux's The Three Daughters of M. Dupont and The Incubus, as well as in The Unwritten Law his own adapta- tion of Dostoievsky's Crime and Punishment and in Lengyell's Typhoon. In 191 2 he acted lago in Herbert Tree's production of Othello. He wrote Peter the Great, produced by his father in 1898, Bonnie Dundee and Richard Lovelace, as well as a number of translations and adaptations of plays. Both he and his wife lost their lives when the " Empress of Ireland " sank in the St. p Lawrence river May 29 1914.
ISOSTASY, in Geology. When the Great Trigonometrical Survey of India was initiated, it was found that the deflection of the plumb-line by the Himalayas was much less than the calculated amount due to the theoretical attraction of the visible mass of the mountains. Sir G. B. Airy suggested that this might be caused by the presence of a mass of matter, of less than the average density, under the mountains; this explanation was further investigated by Archdeacon J. H. Pratt, who applied the term compensation to the negative effect of the underlying defect of density, in compensating the direct effect of the attraction of the visible mass of the mountains. In 1892 Major C. E. Dutton, discussing the greater problems of physical geology, deduced a general principle that the weight of matter under any unit area of the earth's surface tended to become uniform, and suggested that this was brought about by an underground transfer of ma- terial to balance the visible surface transport from regions of erosion to those of deposition. To this principle he gave the name isostasy (tow, equal, and ordfftj, position), not as a synonym for Pratt's compensation, but as a name for the princi- ple and process by which it was brought about. In 1909 there appeared a very complete and elaborate investigation of the subject, by J. F. Hayford, in which the word isostasy is used throughout as synonymous with what Pratt called compensation, and this use of the term has since become general among geode- sists. Some inconvenience results from this change in the mean- ing attached to the word, for it is still largely understood by geologists in the sense intended by its inventor, as the process by which the fact implied by Pratt's word, compensation, is brought about (see also GEOLOGY).
See G. B. Airy, Phil. Trans., cxlv., 1855, p. 101 ; J. H. Pratt, Phil Trans., cxliv., 1859, p. 745; C. E. Dutton, Bull. Phil. Soc. Washington, xi., 1892, p. 51 ; J. F. Hayford, The Figure of the Earth and Isostasy, from Measurements in the United States (Washington 1909). (R. D. O.)
ISRAELS, JOSEF (1824-1911), Dutch painter (see 14.885), died at The Hague Aug. 12 1911.
ISVOLSKY, ALEXANDER PETROVICH (1856-1919), Russian statesman, was born in 1856 in the government of Vladimir, of a family which for generations had appertained to the lower officialdom. At the age of 20 he received his first diplomatic appointment at Rome, and was thence transferred to Philippopolis and Bucharest, where, by the patronage of Princess Urussov (wife of a future Russian ambassador at Paris), he made his reputation. Thence he was sent to Washington and the Vatican. At this time he was already so much the coming man that, upon the retirement of Count Lobanov, his mother-in-law, Countess Toll, saw fit to inform Count Muraviev that her son-in-law, upon his appointment as foreign minister, would bear him in mind. Muraviev, who already carried his nomination in his pocket, resented this condescension, and relegated Isvolsky to Belgrade and to Munich, where he had the rank of a minister plenipotenti- ary. Returning to favour in 1 899, he was promoted to the Legation at Tokio, where, however, under the influence of German reports concerning the Japanese army and especially its artillery he misjudged Japan's advent as a Great Power. His eleventh-hour conversion could not avert the conflict of interests which led to the war of 1904-5, from which Russia emerged defeated, but enabled him to veil a serious diplomatic error by relinquishing the odium of failure to his successor, Rosen. He himself went to Copenhagen, where he negotiated the passage of Adml. Rozhestvensky's fleet through the Great Belt (Oct. 1904). There also, in July 1905, he had his historic interview with the Emperor William II. in which an alliance between Russia, Germany and France was proposed. Isvolsky was ignorant of the " personal " treaty of defensive alliance " between Germany and Russia, entered into by the respective sovereigns at Bjorko." Though this secret compact did not bear his signature (since he had not been present), the Russian Minister for Foreign Affairs, Count Lambsdorff, fell over its repudiation, and was, in May 1906, succeeded by Isvolsky.
Russia's military prestige was at a low ebb, her finance in a state of chaos, the Tsarist r6gime discredited and the country in the throes of revolution. At this time, Isvolsky displayed great physical courage in that he went about St. Petersburg un- attended, but also great lack of faith in the existing order, since, having discovered that through an irregularity his pay depended on the Privy Purse, he caused it to be charged to the Treasury as the first act of his tenure of office. He also raised his brother to the office of Procurator of the Holy Synod and his Goadachev relations to high diplomatic appointments.
Slowly he restored the national prestige, for he asserted loyalty to France as the first principle of policy and brought about the Anglo-Russian agreement in Persia of Aug. 31 1907, which was followed on June 9 1908 by a meeting between King Edward VII. and the Tsar Nicholas II. near Reval. The long Balkan troubles of 1908-12, which originated in Count Aehrenthal's exploitation of Russia's transitory weakness, called for great care, especially during the crisis of 1908-9, which laid bare Russian impotence. After four years at the Foreign Office, which gained Russia the time she needed to recuperate, Isvolsky suc- ceeded M. Nelidov as Russian ambassador in Paris. He lived to see the World War of 1914 and the Russian revolution of 1917, which forced him into impoverished retirement at his villa at Biarritz. He died on Aug. 18 1919. An accomplished man of letters, a competent critic of art, a linguist of rare perfection and charming in manner, but cynical and pleasure-loving, he was certainly one of the chief diplomatic personages in the reign of the last of the tsars. He married Marguerite Carlovna, nee Countess Toll, a Bait of great charm whose influence at court was impeded by her ignorance of the Russian tongue. By her he had one son, who fought in the Dardanelles.
(W. L. B.)
ITAGAKI, TAISUKE, COUNT (1837-1920), Japanese statesman (see 14.887), died in 1920. True to his radical principles, he forbade his son to apply for the succession to his title, and it lapsed.
ITALIAN CAMPAIGNS, 1915-8. At the outbreak of the World War the Italian general staff had no worked-out plan for an offensive campaign against Austria-Hungary. The omission was not due to the fact of the Triple Alliance, for the prospect of war on the N.E. front had always been faced, but to the relative military position of the two countries. The Habsburg Empire had a great superiority over Italy in organized and potential man-power and in material, but the controlling factor which seemed to deny the possibility of Italian offensive action was the frontier drawn in 1866. The Trentino salient, thrust down like a great wedge to within a few miles of the Lombardo-Venetian plains, dominated the strategical situation. Nor was the hampering influence of the frontier confined to a practical veto upon attack. Its length in relation to Italian military strength, and above all the fact that the threat of the Trentino came so far west in the long line, meant that Italy's defensive frontiers were far from being coterminous with her political boundaries. The first possible line of defence was held to be the Tagliamento, with its fortified bridgeheads at Osoppo, Codroipo and Latisana; plans had been drawn up with the Piave as the main line of resistance, though with the intention of meeting the enemy in the plain E. of the river; but there was much to be said for the contention that the true military frontier of Italy was still the line of the Mincio and the Po.
