Portraits present sitters as they wish to be perceived. Dressed for success, the up-and-coming Cox (1736-1806), a master mechanic, strikes the nonchalant pose of a gentleman. A dazzling white stock (scarf) wound tightly below his chin sets off his superbly painted visage. One languid hand drapes easily below a crisp white ruffled cuff; the other is thrust into his waistcoat in a gesture recommended by etiquette books to express “Decency and genteel Behaviour.” The year Cox sat for this portrait, he designed a yarn-processing machine, reducing American dependence on English fabrics amid growing resentment of British taxation on imported goods. Although Cox took the side of the patriots in 1770, he seems to have altered his political views by 1775, when he was briefly imprisoned on suspicion of spying for the British. He left the country shortly thereafter. On his return, Cox’s engineering skills as a bridge designer eventually brought him fame, if not fortune. In 1785–1786, Cox supervised construction of the first bridge to span the River Charles at Boston, Massachusetts. He designed another bridge in Waterford, Ireland, in 1793. Colloquially called Timbertoes, it was as solid as its confidently posed designer, remaining in use into the early 20th century.