Sentence:  I looked again, and though I was sensible it must be a delusion brought on by the stroke of his powerful rod, yet I did see the appearance of a glorious fleet of ships coming bounding along the surface of the firmament of air, while every mainsail was <WSD>bosomed</WSD> out like the side of a Highland mountain. 
Meaning of the word marked with <WSD> tags:  To belly; to cause to billow, swell or bulge.