86 ALL AFLOAT 



over the junctions of the deck beams with the 

 ship's sides, to both of which they are securely 

 fastened. 



The keelson was an old invention and shelf- 

 pieces and waterways were soon in vogue. 

 But fillings and trusses, both expensive im- 

 provements, were not much favoured in any 

 mercantile marine. The truss is even older 

 than the keelson, having been used by the 

 ancient Egyptians at least thirty-five centuries 

 ago, and probably earlier. Four to eight 

 pillars rose in crutches from the bottom amid- 

 ships to about six feet above the gunwale. 

 The Egyptians ran a rope over the crutches and 

 round the mast, and then used its ends to brace 

 up the stem and stern. The moderns discarded 

 the rope, took the strains on connecting 

 timbers, and modified the truss, sometimes out 

 of recognition. But many Canadian and 

 American river steamers of the twentieth 

 century A.D. employ the same principle for 

 the same object as the Egyptians of the seven- 

 teenth century B.C. Fillings came from the 

 French, like shelf-pieces and waterways. 

 Seppings put them between the ribs, in the 

 form of thick timbers. The whole frame thus 

 became almost solid against any tendency of 

 the ribs to close together, and quite strong 



