Page:Popular Science Monthly Volume 21.djvu/283

Rh enabled to visit the Pribylov Islands and study the life and habits of the animals. The notes, surveys, and hypotheses here presented are founded on his personal observations in the seal-rookeries of St. Paul and St. George, during the seasons of 1872, 1873, 1874, and 1876. They "were obtained through long days and nights of consecutive observation, from the beginning to the close of each seal season," and cover, by actual surveys, the entire ground occupied by these animals.

question, "What constitutes the area of the United States?" is by no means a simple one, but involves other questions of including or leaving out inlets, and the measurement of numerous gores. For the purpose of this work the main area was procured by summing up the square degrees, and the areas of the fractions of square degrees were computed after direct measurement, with scales on the maps of the Coast, Lake, and Mexican Boundary Commission surveys. The whole contour of the country is thus given by surveys whose accuracy is unquestioned, except as to the part between the Lake of the Woods and Lake Superior, and a part of the eastern boundary of Maine, of which exact surveys have not been made. The same principles were observed in computing the areas of States and counties, where, however, boundary surveys are often not so accurate as they should be.

statistical statement is offered in advance of the author's report on the production of the precious metals, of which it will form the concluding chapter, on account of its immediate interest to legislators, financiers, and metallists. It consists almost wholly of statistics, presented in a full and clear manner.

Signal Service continues to manifest its value, particularly in the meteorological department. The present officer, General Hazen, has endeavored to bring it into active sympathy and co-operation with men of science; and it enjoys the assistance of an advisory committee of the National Academy of Sciences. The work of the year has been marked by advance in nearly every department, among the evidences of which we notice the establishment of a permanent school of instruction at Fort Myer, Virginia; the extension of forecasts to periods of more than twenty-four hours; the forecasts of "northers" for the interior plateau; the extension of the special frost-warning to the fruit interests; the organization of a service for the special benefit of the cotton interest; arrangements for original investigation in atmospheric electricity, in anemometry and in actinometry; and in the last subject, especially with reference to the importance of solar radiation in agriculture, and the absorption of the sun's heat by the atmosphere; the publication of special professional papers; the offering of prizes for essays on meteorological subjects; the organization of State weather services; co-operation in work in the Arctic regions; arrangements for organizing a Pacific coast weather service; and a large increase of telegraphic weather service, without additional expense to the United States. The popular confidence and support of the bureau, General Hazen says, have never been impaired, and the scope of its usefulness increases with each year.

work and Professor George F. Becker's "Digest" of the investigations of "Atomic Weight Determinations, published since 1814," which forms Part IV of the series of "Constants," are complementary to each other. Professor Clarke began his investigations in 1877, for the purpose of