I'm in the book, but not on any leaf; I'm in the mouth, but not in lip or teeth; I'm in the atmosphere, but never in the air; I wait on every one, but never on a pair; I am with you wherever you may go; And every thing you do I’m sure to know; Though when you did it I should not be there, Yet when ’twas done, you’d find me in the chair. What am I?
I am a word of three syllables, each of which is a word; my first is an article in common use; my second, an animal of uncommon intelligence; my third, though not an animal, is used in carrying burdens. My whole is a useful art. What am I?