Bull. U. S. B. F., 1917-18. 



Plate XXXVII. 



Fig. I. — Tubular saws of different sizes, saw and sptm fitted iato the chuck, and shell from which 



blanks have been cut. (See p. 71.) 



Fig. 2. — Blanks of various sizes and thicknesses as cut from the shell and before submission to the 



"backing" process. (Seep. 74) 



Fig. 3. — Finished buttons of several sizes and patterns. (See p. 76.) 



