[4.] “Notes on Explosives, Mine Gases and Dusts,” by Rollin Thomas Chamberlin. Bulletin No. 383, U. S. Geological Survey, 1909.
[5.] “Prevention of Mine Explosions,” by Victor Watteyne, Carl Meissner, and Arthur Desborough. Bulletin No. 369, U. S. Geological Survey.
[6.] With a view to obtaining a dust of uniform purity and inflammability.
[7.] “The Primer of Explosives,” by C. E. Munroe and Clarence Hall. Bulletin No. 423, U. S. Geological Survey, 1909.
[8.] “Tests of Permissible Explosives,” by Clarence Hall, W. O. Snelling, S. P. Howell, and J. J. Rutledge. Bulletin No. * * *, U. S. Geological Survey.
[9.] “Structural Materials Testing Laboratories,” by Richard L. Humphrey, Bulletin No. 329. U. S. Geological Survey, 1908; “Portland Cement Mortars and their Constituent Materials,” by Richard L. Humphrey and William Jordan, Jr., Bulletin No. 331, U. S. Geological Survey, 1908; “Strength of Concrete Beams,” by Richard L. Humphrey, Bulletin No. 344, U. S. Geological Survey, 1908.
[10.] “Fire Resistive Properties of Various Building Materials,” by Richard L. Humphrey, Bulletin No. 370, U. S. Geological Survey, 1909.
[11.] “Purchasing Coal Under Government Specifications,” by J. S. Burrows, Bulletin No. 378, U. S. Geological Survey, 1909.
[12.] “Experimental Work in the Chemical Laboratory,” by N. W. Lord, Bulletin No. 323, U. S. Geological Survey, 1907: “Operations of the Coal Testing Plant, St. Louis, Mo.” Professional Paper No. 48, U. S. Geological Survey, 1906.
[13.] Also Bulletins Nos. 290, 332, 334, 363, 366, 367, 373, 402, 403, and 412, U. S. Geological Survey.