His own secret device

Walter Kenyon, «  Manuel Training: Its Geometry and Mensuration », The School Journal, New York & Chicago,  vol. 56, n° 7, 12 février 1898, p. 185.

 

The caddis-worm, in the beds of brooks, and ponds, makes himself an overcoat of sticks or pebbles, cemented together by his own secret device. Making comes before drawing, as Col Parker has reiterated from the outset. The savage devises his water jars generations before he bethinks to decorate them.