HISTORY. 
99 
by a wrapping of twisted wire like that recently used by certain 
engineers. 
This first patent was afterwards several times modified. Brett 
had proposed the use of what he termed a “ vertebrated iron 
tubular cable ” (Fig. 36), intended to protect the telegraph 
Fig. 36. Fig, 37 
wire near the shores from damage by anchors and similar 
accidents. This cable would bear a great strain, and could be 
considerably bent without injury or derangement. Fig. 37 
represents one of these cables strengthened by chain links for 
places where a still greater protection is needed. 
