[85]. See article by J. R. Gow, Journal New England Waterworks Ass’n, Sept., 1920, also Public Works, Vol. 50, p. 98.
[86]. Diameter of diaphragm.
[87]. Gallons per minute.
[88]. Eng. News, Vol. 75, 1916 p. 1050.
[89]. Mun. Engineering, Vol. 53, p. 6.
[90]. For types of drill bits see article by T. H. Proske, Mining and Scientific Press, March 5, 1910.
[91]. These intermediate holes are seldom more than 3 feet apart.
[92]. Earth Pressures, Old Theories and New Test Results, Eng. News-Record, Vol. 85, 1920, p. 632.
[93]. Trans. Am. Society Civil Eng’rs, Vol. 60, 1908.
[94]. Adopted by the Am. Ry. and Maintenance of Way Ass’n in 1907.