Department, attends to the proper illumination of our coasts and rivers. One research of Joseph Henry's upon the oils used for lighthouse lamps saved the Government hundreds of thousands of dollars; and, to-day, the application of the electric light to coast illumination calls for the most careful consideration of scientific experts. The Department of Agriculture also does much in the application of scientific research to the assistance of great industries. It investigates the wasting of our forests, determines the conditions favorable to crops, conducts experiments upon sorghum, studies the plagues which ravage our flocks and herds, and seeks for methods of exterminating insect pests, such as the locust, the cotton-worm, or the potato-beetle. It employs chemists, botanists, entomologists, microscopists, and veterinary surgeons; and their labors can not but be fruitful of much good. Like it in aim, though working in a different direction, is the younger Fish Commission, which restocks our depleted waters, investigates the habits and food of fishes and the best modes of preventing their extermination, and literally creates new sources of wealth for the people.
Under the Treasury Department, in addition to the Lighthouse Board, are several other bureaus which depend more or less upon science. The Mint and Assay Offices, for example, have much to do with chemistry; and, to a certain extent, with physical problems also. The Bureau of Engraving and Printing, which manufactures our national bonds and notes, often has need of assistance from scientific experts; and so too have the custom-houses in the settlement of questions relative to certain duties. The Coast and Geodetic Survey, which is almost purely scientific in character, not only maps our coast-line with the utmost accuracy, but also furnishes the primary triangulation of the interior. This triangulation is the basis for all accurate mapping of the several States, and is done by men of the highest scientific training. An error in the boundary-line between two States may throw doubt upon the transfer, taxation, or inheritance of real property; or, by calling in question the jurisdiction of a court over disputed territories, it may defeat the ends of justice. Hitherto, when such doubts have arisen concerning State boundaries, the United States Government, represented by the Coast Survey, has been the arbiter. This survey also controls our magnetic observatories, in which the variations of the needle are recorded, and has custody of the standard weights and measures. The latter duty is one of the utmost importance, and involves the use of the most delicate instruments of precision.
The Geological Survey is under the Interior Department, and has several functions. It determines the geological structure of the country, joining and completing the scattered details of the several State surveys, develops more fully the principles of geologic science; and, from an economic point of view, investigates our mineral resources.
