Quake-buttock

See what theſe times are grown to, before twenty / I ruſh'd into the world, which is indeed / Much like the Art of ſwiming, he that will attain to't / Muſt fall plump, and duck himſelf at firſt, / And that will make him hardy and advent'rous, / And not ſtand putting in one foot, and ſhiver, / And then draw t'other after, like a quake-buttock; [...]