From Introduction: "The lack of comparable and accurate statistics of coal-mine accidents in the united States as a whole led the Bureau of Mines in 1911 to undertake the collection of such data. The mining departments of the leading foreign coal-producing countries have long taken cognizance of the importance of statistics. The bureau feels that in presenting the tables embodied in this report it is offering the and comparable statistics of coal-min accidents for the country as a whole that have ever been published."

From Introduction: "Although the purpose of this paper is to describe gold dredging in Montana, a brief mention of some early appliances used in New Zealand, Australia, and California may serve as a world-connecting link in our consideration of the development of gold dredging."