His Majesty* s Ships of JVar, 297 
composed, so that a ship, let her construction be what it may, 
either loose or firm, is not in any case elastic. It follows then, 
that every action and reaction of the sea operating upon dif- 
ferent parts of the fabric at different times, occasions, for the 
want of unity of the whole of the parts, a constant and in- 
creasing weakness, which by some may have been taken for 
elasticity. 
When a sea strikes a ship forward, the bow will rise with 
the sea ; which passing aft, lifts the midships in succession, 
leaving at this time, in a great measure, the fore and aft parts 
of the ship with comparatively little, or no support. Such 
shocks, acting upon a body whose parts are not firmly con- 
nected, produce a bending and rebending of the fabric, so that 
the several planks of the sides play over each other, and the 
fastenings are strained and loosened by a repetition of this 
action and reaction. On the contrary, when a body is con- 
structed with such general unity and fixedness of all its parts, 
as that if one is moved the whole must move with it, then it 
may be said that all the parts of the structure bear their por- 
tion of the strain. 
The decks come next under consideration, the beams of 
which are disposed in the new system nearly as usual, except 
that in midships, where a ship necessarily requires the greatest 
security, two additional beams have been introduced. 
The beams of the several decks are attached to the ship's 
side in the following manner. 
1st. Ey shelf pieces or internal hoops, distinguished by the 
letter E, figure 2. These shelf pieces are composed of several 
lengths of timber scarphed or joined together by coaks, or 
circular dowels, so as to form a kind of internal hoop, extending 
