86 BULLETIN OF THE BUREAU OF FISHERIES. 
that in the long run the interest of cutter or manufacturer is promoted by waste or 
antagonism to legitimate improvement. 
PROPORTIONS OF PRODUCT AND WASTE. 
The unavoidable waste in the commercial use of mussel shells is remarkably high, 
assuming the most economical use possible of materials under present conditions. The 
waste involved in the combustion of coal is often cited as an example of unavoidable 
loss, where, under the most efficient methods in use, only a small per cent of the latent 
energy is converted into power. In button manufacture we find that only 5 to 8 per cent 
of the original gross weight of the mussel enters into the button product; but the re- 
mainder in this case is not all lost, since there are waste products which are utilizable 
at a less profit. In the first place, when the mussel is taken from the river, we find 
that about 3 per cent of the dry weight is thrown out as meat.? The losses in the shell 
at different stages of manufacture, as determined by averages from several specific 
tests made by J. B. Southall, are shown in the following table: 
LossES IN SHELLS OF CERTAIN SPECIES DURING MANUFACTURE OF BUTTONS. 
Lake . 
Waste or by-product. Pepin a 
Per cent. 
Diseardeéd dhielf. ct cct SATA PETES. FAN, OT. TSS TT Abs Si awison c ctheily oe add. smn eater eee «8 60. 8 73-6 
Dust in sawing blank «1... 1... 5-2 eee e ee eee ener een eet teen teeter neta e ene ee tees eeteneee ee ee ses 16.9 8.8 
Dust in grinding and finishing button ............-... PMG cincate ROME Se a wtdtate cat URAL WS 12.9 10.8 
Total wasteor By-Products 0)5. cjeicid Soe o Liaewlals me aie kidiciem slablolaleiels vleldslem a WaN Renee b RAT ae sv eth e lctetnls WAM 90. 6 93-2 
Weight of Hitt tons os. oly sseln s aes cians Desai Wee erat ae aera ae ere one ie elas einai ai 9-4 6.8 
Lh» t BEEP e ROE AR cet dtc AGREE” DRECOR SEE SEOs IAneE nema ESEene anne Crnpeeoarrnormcrer code Sande 100. 0 100.0 
Roughly speaking, 7 per cent of the total weight of heavy shells like the niggerhead 
is marketed from the factory in a form worth $2.16 per pound,® while of the remaining 
93 per cent, a portion is entirely thrown away and another portion sold as crushed shell, 
or dust, at a quarter of a cent per pound.° 
The table and data are not of purely academic interest. They point to the signifi- 
cance of the problem of the utilization of the now unavoidably wasted material, and 
they emphasize the importance of putting more of the shell into the high-priced 
product, the buttons. 
It remains to differentiate the instances of waste which are prevented by correct 
practice in cutting and those which arise from the form or character of the shell, and 
which consequently may be obviated only by new discoveries in method or by changing 
demands of the trade. 
WASTE IN CUTTING. 
It may be conceded that there is some waste which it would be possible but 
not desirable to avoid. Given the present economic conditions, it will appear that 
parts of the shell which could be cut are better left uncut, because the cost in labor 
@ The proportion of dry meat to shell varies widely with the different species. It is safe to say, however, that, on the 
average, the meats with all water dried out represent one thirty-fifth of the total dry weight of the mussel. The utilization of 
the meats is discussed in part 2, page 6r on the mussel fishery. 
> Figuring 1,248 buttons to the pound at 25 cents the gross (good quality 16 line). 
¢ Price of crushed shell, $5.50 per ton. Price of dust, $4 per ton. 
