not sufficiently practical. In the case of the Geological Survey it has been said that the people needed practical results to assist them in their material development, and that abstract studies should be left to the universities and technical schools. The critics fail to recognize the fact that scientific or technical knowledge is necessary to the solution of any geologic problem, and that, if it is not already in existence, investigations must be made in order to obtain it for the purpose. Geology is essentially a science of exploitation; and the geologist must have at his command the best instruments and most reliable information that can be obtained to aid him in observing, in recording the results of observation, in classifying and assimilating such results, and in correctly interpreting them. He must also have a knowledge of the principles and laws that govern the phenomena under investigation, and if it is only by experimentation and special research that he can obtain such knowledge, then the time and energy must be expended to secure it. In view of these facts there is no necessity for apology for the existence of chemical, lithological, physical, and paleontological laboratories in connection with the Geological Survey, nor for special studies in the glacial formations, the physics of the earth's crust, etc. They are all essential to its scientific and practical work, and to the securing of results that will command the confidence of all who may have occasion to use or refer to them. The survey will keep in view the fact that it receives its support from the people, and endeavor to give in return practical results, and at the same time to furnish information that will advance the higher education, and especially the science of geology, in America.
Co-operation.—The recommendation of the National Academy of Science, that "all mensuration surveys be consolidated under one organization," was not adopted; nor could it have been fully successful as outlined in the plan submitted to Congress. If the topographic surveys were governed by any other condition than that of being made principally for the geologist, in the territory where his work demands the maps, they would be more likely to prove a hindrance than an assistance to him. An illustration may explain this. During the past field season it became desirable to make a geologic survey of the western Maryland coal field. The old topographic map of that area being found inadequate to supply the data required, a topographic party was sent with the geologists; but as the season advanced it became apparent that the one topographic party could not keep pace with the geologists, and a second and third topographic party were sent to their assistance. Jointly they completed both the topography and geology of that area before the close of the season; and the maps will be published within a year of the sur-