POPULAR SCIENCE MONTHLY.
The conditions in the United States have been favorable to the development of geology. The varied forms of the land have offered abundant opportunities for research, whereas the practical value of the work has led to the establishment of surveys, the magnitude of whose contribution to geology is only known to special students. The Geological Society of America has about two hundred and fifty members, nearly all of whom are actively engaged in geological research, perhaps a larger number than in any other science. The U. S. Geological Survey is the center of this movement, and its great efficiency is in large measure due to Mr. G. K. Gilbert, now president of the American Association for the Advancement of Science. He was born in Rochester, N. Y., in 1843, and after graduating from the university in that city, acted for five years as assistant in the Ward Museum, where a number of eminent naturalists have been trained. He then became geologist in the Ohio Survey under Newberry, was engaged in the Wheeler and Powell Surveys, and has been geologist in the U. S. Geological Survey since its establishment in 1879. In the arid west, where the face of the earth is bare, Mr. Gilbert made the observations and discoveries in dynamical and physical geology which have done so much toward the making of the science of physiography. His monographs on the Henry Mountains and on Lake Bonneville, the name he gave to the ancient lake that once filled the Utah basin, are models, both in regard to their original discoveries and the methods of presentation. He has extended his studies to the basins of the Laurentian Lakes and to other regions, always with important results. Mr. Gilbert has been president of the American Society of Naturalists, the Geological Society of America and the Philosophical Society of Washington, and has received the Wollaston Medal of the Geological Society of London. His presidential address. before the American Association will be given at the American Museum of Natural History, New York City, on the evening of June 26, his subject being 'Geological Rhythm.'
The meeting of the American Association in New York City, opening as this issue of the Monthly is published, promises to be of more than usual importance. The preliminary programs of the different sections show long lists of valuable papers and promise the attendance of leading men of science from all parts of the country. A movement of interest is the increasing tendency of special scientific societies to meet in conjunction with the Association. No less than fifteen societies will this year hold their sessions at Columbia University, some of them joining with the sections of the Association, and others holding independent meetings. The members of these different societies have the advantage of the reduced railway rates and other arrangements which can be made once for all, and the still greater advantage of meeting scientific men in other departments. As science grows in details and in range, there is on the one hand an increased specialization, making it desirable for small groups of experts to meet together to discuss their special problems, while, on the other hand, almost every scientific question has ramifications extending to many sciences. Hence, the need of many separate societies and at the same time of a common meeting ground. When the American Association was organized, in 1848, its members could meet in one body; later they