FRESH-WATER MUSSELS AND MUSSEL INDUSTRIES. 75 
be obnoxious and injurious to employees (Pl. XX XIX, fig. 1). Grinders are paid from 
15 to 25 cents per 100 gross, according to size and thickness of blanks, earning from $9 
to $15 per week. 
Finally the blanks are again soaked in water to be softened for the finishing machine. 
In some cases, if too much mixed in quality or size, the blanks may be sorted by hand. 
MAKING THE ButTrons.—Having been classified, tumbled, backed, and soaked, 
the blanks are now ready for the essential processes of button making, which are accom- 
plished by an automatic machine of comparatively recent invention and of very ingenious 
design. The illustration (Pl. XXXVI, fig. 2) will aid in an understanding of the brief 
description of the working of the machine which can be here given. (Seealso Pl. XXXIX, 
fig. 2.) The blanks are fed by hand into depressions in the tops of vertical chucks, which 
are arranged in series constituting an endless chain. As the chucks in endless chain pass 
around the circumference of the machine each blank is automatically operated upon by 
various tools, and each tool is automatically sharpened and prepared for the succeeding 
blank. The processes accomplished in the machine consist in rounding the edges and 
carving out the center in the desired pattern to make the face of the button and in drilling 
two or fourholes according to pattern. After the first hole the drillrises, the button makes 
a turn through a fourth or a half of one revolution (according to whether it is to be a 
four-hole or two-hole button), when the drill again descends to make a new hole. After 
the last hole is drilled the chuck opens automatically to release the button, which is 
sucked into a tube connected with the blower system to be dropped into a bucket 
through a counting tube. 
Some twenty-odd distinct operations are combined in the double automatic machine, 
and it is interesting to record them. Let it be noted that the button travels in an oblong 
orbit, while the carving tools and the drills, respectively, travel in smaller circular orbits 
at opposite ends of the button orbit. 
1. The traveling chuck, which is open after releasing a finished button, closes on the 
new blank placed in the top depression. 
2. The chuck with the blank begins to revolve rapidly on its axis while continuing 
to travel to the right. 
3. The face of the revolving and traveling button is applied to a carving tool of 
proper form to make the desired face. The tool itself is stationary on its axis, but travels 
in orbit with the buttons. 
4. The facing completed, the tool rises. 
5. The rotation of the blank is stopped. 
6. The tool, continuing on its orbit, is sharpened on an emery wheel. 
7. Before meeting another blank the tool is lowered by a small fraction of an inch 
to compensate for the shortening due to the grinding on the emery wheel. 
8. The chuck, with its blank, leaves the orbit of the carving tool at a tangent to 
pass over to the orbit of the drilling tools. 
g. When the blank is in just the right position, one of the drills descends to make 
the first hole in the blank. In this operation the drill revolves, while the blank is station- 
ary on its axis, but both travel together. 
10. The drill rises. 
11. The chuck, with blank, turns through one-fourth of a revolution. 
