UTILIZATION" OF DOGWOOD AND PERSIMMON 
27 
contents in board feet pay from 35 to 75 cents a board foot, again in 
accordance with size. 
The average board foot contents of shuttle blocks from 12y 2 to 
I6V2 inches in length, carried in stock by one manufacturer, was 
three-tenths of a board foot, and of shuttle blocks from I7y 2 to 30 
inches, 1^4 board feet. Two-fifths of a board foot is the figure 
generally used in computing. This represents an average block 
slightly smaller than 2 by 2 by 16 inches. 
The actual process of making shuttles starts with the selection of 
blocks which have been carefully kiln-dried to a moisture content^ of 
5 to 8 per cent. The rough blocks, which have been somewhat dis- 
torted in shrinking, are surfaced on all sides. The surfaced blocks 
Fig. 18. — Stages in the manufacture of a shuttle (15 inches in length). Nos. 1 to, 4, 
persimmon ; No. 5, dog-wood 
then go through a number of boring, turning, and trimming proc- 
esses before the necessary metal parts are inserted. (Fig. 18.) Be- 
fore final finishing they are dipped to make them somewhat moisture- 
resistant, usually either for a short period in hot linseed oil, or over 
night in cold linseed oil. 
Most manufacturers have encountered at some time or other during 
the process of manufacturing shuttles a tendency of the wood to 
check, owing to a change in atmospheric conditions, loss of moisture 
within the block, and consequent shrinkage. Linseed oil, often used 
in such emergency cases, is partially successful in reducing the 
rapidity of moisture loss. It must be stated, however, that for perma- 
nently preventing the loss or gain of moisture by the shuttle, linseed 
