[14] E. H. Knight, American mechanical dictionary, Boston, 1884, vol. 3, p. 2033.

[15] Henry Disston & Sons, Price list, Philadelphia, 1897, p. 28.

[16] Ardrey, op. cit. (footnote 2), p. 166.

[17] Ibid., p. 166.

[18] James M. Swank, History of the manufacture of iron in all ages..., Philadelphia, 1892, pp. 390, 393.

[19] Country Gentleman, 1857, vol. 10, p. 129.

[20] Reports on spark test by E. A. Battison, U. S. National Museum, and on metallurgical investigation by A. H. Valentine, Metallographic Laboratory of the Bethlehem Steel Company's Sparrows Point Plant.

[21] For this information I am indebted to Mr. E. A. Battison of the U. S. National Museum staff.

[22] Abraham Rees, The cyclopaedia; or universal dictionary of arts, sciences, and literature, Philadelphia, 1810-1842, vol. 33, under saw.