Not just a highchair, but a piece of furniture which would also weigh and exercise a child.
Parents worrying about their children’s weight and how much exercise they get is nothing new, although in the past the concern was mainly that children didn’t weigh or grow enough. Even in wealthier families nutrition was poor and not well understood. Typical food for children was bland, overcooked and stodgy, and didn’t contain enough protein or fibre.
Edward Emmons invented this design in the USA in 1856 to help parents with the problem. A contemporary advertisement states that Wilson, Newton & Co of High Holborn, London later took out a UK patent for it. It can be used as an ordinary high chair, but has two extra features. The seat is mounted on a spring, and a child sitting in it could grasp a handle on each side and get lots of healthy exercise by bouncing up and down. There was also originally a mechanism which made the seat work like bathroom scales: as soon as children sat in the chair, it showed their weight. The chair was also marketed as having play value, since it could be used to keep a child amused, particularly in conjunction with songs, stories or clapping rhymes.