Sentence:  When you have got your junks wormed and laid up, take each two pieces, and stop them together; double the middle pieces, and stop them also, and clap a good stop on, to form the eye: then bring them all together upon some <WSD>dunnage</WSD>, to keep them up from the deck, to enable you to pass your round-about lashings: 
Meaning of the word marked with <WSD> tags:  Scrap material, often wood, used to fill spaces to prevent the shifting of more valuable items during transport, or underneath large or heavy items to raise them slightly above the ground, in order to protect from chafing and wet.