The figures given above are, of course, based upon counts and
computations of shells from a particular locality and must not be
assumed to have any general application, but the facts and principles
derived do have a universal bearing. If such a size limit as 2 inches
is adopted, the saving to the mussel beds and to the future of all
interested parties is out of all proportion to the immediate loss to
any party; and even the immediate loss is to some extent compensated by
the saving resulting from having to do with a lesser number of shells
that yield a greater number of buttons per ton.
Undeniably some temporary sacrifice is entailed, but unless it be
admitted that temporary sacrifice will be accepted, it is useless to
consider any manner of restriction for ultimate benefit.
There is one point that is brought out in the table on page 14 that
merits attention from the broad standpoint of economy. In all shells
there is a proportion of unavoidable waste, since the entire weight of
the shell can not be transformed into buttons. In very small shells we
may expect an undue waste, on account of the fact that only one or two
blanks can be cut out, leaving a larger bulk of shell in proportion to
the number of blanks gained. On the other hand, in very large shells a
high degree of waste is involved because of excessive thickness, which
must be ground from the blanks, and because of the extra weight of the
discarded portion. Somewhere between these extremes is the size of
shell that yields the largest number of blanks as compared with the
waste or the weight of shell that does not go into buttons. As shown by
the data in the fifth column of the table, the shells a little above 2
inches in size are those (for this species) that make the best yield
per ton for the small lines for which there is the greatest general
demand.