Inventor. Born in Arbroath, Chalmers was a weaver who moved to Dundee in 1809, becoming a bookseller, newspaper publisher and printer. He first suggested the adhesive postage stamp in 1834 and submitted his ideas to Parliament in 1839, which made Rowland Hill's Penny Postal Service a practical proposition.
Chalmers was buried in the Howff (Dundee), where the inscription on his gravestone proclaimed "Originator of the adhesive postage stamp, which saved the penny postage scheme of 1840 from collapse". Chalmers' family and friends fought hard to ensure his contribution was recognised, Hill having received the credit, together with a knighthood and substantial honorarium.