Page:Popular Science Monthly Volume 42.djvu/733

Rh Smaller exhibitions were held in Melbourne in 1854, Turin in 1856, Brussels in 1857, Lausanne in 1858, and Hanover in 1859. The second International Exhibition in London was held in 1862, covered 17 acres, was visited by 6,210,000 persons, and lost $2,001,500. The second Great Exhibition in Paris, in 1868, covered 11 acres besides many annexes, and had 52,200 exhibitors and 10,200,000 visitors. The Great Exhibition at Vienna in 1873 failed on account of the cholera. The Centennial Exhibition in Philadelphia in 1876 occupied 285 acres; was participated in by 32 foreign nations, while the United States furnished 30,864 exhibitors, Great Britain and its colonies 3,584, and Spain 3,822; and was visited by 9,911,000 persons. The Paris Exhibition of 1878 covered 54 acres, with annexes and special buildings; had 52,835 exhibitors, of whom 1,203 were American; was attended by more than 16,000,000 visitors; and lost $S,580,000. The Paris Exhibition of 1889 exceeded all these, and had 30,000,000 visitors. The Chicago Exhibition will occupy 666 acres, of which more than 200 acres will be crowded with buildings. The total expense of it will be between $8,000,000 and $10,000,000.

New Studies for Grammar Schools.—The Association of Officers of Colleges in New England, at its meeting held at Williams College in November, 1892, recommended for gradual adoption in the programme of New England grammar schools the introduction of elementary natural history in the earlier years as a substantial subject, to be taught by demonstrations and practical exercises rather than from books the introduction of elementary physics into the later years, to be taught by the experimental or laboratory method, and to include exact weighing and measuring by the pupils themselves; the introduction of elementary algebra at an age not later than twelve years; the introduction of elementary plane geometry at an age not later than thirteen years; the offering of opportunity to study French, or German, or Latin, or any two of these languages, from and after the age of ten years; the increase of attention in all class-room exercises in every study to the correct and facile use of the English language. In order to make room in the programme for these new subjects, the association recommends that the time allotted to arithmetic, geography, and English grammar be reduced to whatever extent may be necessary.

Rocks and Waters of Arkansas.—Arkansas, says Prof. Branner, in his report on the mineral waters of that Commonwealth, is a well-watered State. Besides the springs of which analyses are given in the report, hundreds of beautiful, free-flowing springs of excellent water gush from hillsides and valleys in all parts of the State. In the limestone region north of the Boston Mountains such springs are especially abundant, large, and beautiful. They are not mineral waters, properly speaking, but they are more valuable than if they were. Some of these springs are so big that they are utilized for driving mills, cotton gins, and other machinery, and, as their discharges are subject to little or no fluctuations throughout the year, they are free from the dangers of freshets and the risks of droughts. Besides these truly gigantic springs, no one who travels through north Arkansas can fail to be impressed by the great number of large and beautiful springs to be found at every town and village, to say nothing of those at almost every farmhouse. Many springs are remarkable for the purity of their waters. The waters of the Hot Springs claim the place of first importance in any consideration of the medicinally valuable waters of the State. It is the custom to speak of a large number of the hot springs, variously estimated at from fifty to seventy; but, while hot water does issue from the ground at as many or more points, it is hardly worth while to dignify each of these trickling streams with the name spring. Much curiosity is naturally manifested on the part of visitors to hot springs regarding the cause of the high temperature of the waters. In the Yellowstone National Park, where hot waters abound, the activity of igneous agencies offers a ready answer to such questions; but in Arkansas, where nearly all the rocks to be seen are of sedimentary origin, there is no evidence of recent volcanic activity. Some of the theories advanced are interesting only as curiosities, and are not mentioned by the author as having any other value. For example, it has been suggested that the heat comes from coal burning beneath the surface