MECHANISM OF THE SPINE 29 



the step, which is formed of large solid pieces of 

 oak timber laid across the keelson. The keelson 

 is an inner keel resting upon the floor-timbers of 

 the ship and directly over the proper keel. These 

 are contrivances for enlarging the base on which 

 the mast rests as a column : for as, in proportion 

 to the height and weight of a column, its base 

 must be enlarged, or it would sink into the 

 earth ; so, if the mast were to bear upon a point, 

 it would break through the bottom of the ship. 



The mast is supported upright by the shrouds 

 and stays. The shrouds secure it against the 

 lateral or rolling motion, and the stays and back- 

 stays against the pitching of the ship. These 

 form what is termed the standing rigging. The 

 mast does not bear upon the deck or on the beams 

 of the ship ; indeed, there is a space covered with 

 canvas betwixt the deck and the mast. 



We often hear of a new ship going to sea to 

 stretch her rigging ; that is, to permit the shrouds 

 and stays to be stretched by the motion of the 

 ship, after which they are again braced tight : 

 for if she were overtaken by a storm before this 

 operation, and when the stays and shrouds were 

 relaxed, the mast would lean against the upper 

 deck, by which it would be sprung or carried 

 away. Indeed, the greater proportion of masts 

 that are lost are lost in this manner. There are 

 no boats which keep the sea in such storms as 



