Buy. U.S. B. F., 1917-18. PLATE XXXVII. 
Fic. 1.—Tubular saws of different sizes, saw and spun fitted into the chuck, and shell from which 
blanks have been cut. (See p. 71.) 
Fic. 2.—Blanks of various sizes and thicknesses as cut from the shell and before submission to the 
“backing’’ process. (See p.74.) 
Fic. 3.—Finished buttons of several sizes and patterns. (See p. 76.) 
