Quadricycles
A Quadricycle is a four-wheeled human-powered vehicle. It is also referred to as a quadracycle, quadcycle, quadrocycle or as a four-wheel bicycle.
The earliest recorded pedal-powered quadricycle was exhibited 1853 at the Exhibition of the Industry of All Nations World's Fair held in New York. This was about the same time that two-wheeled bicycles started to become popular. Quadricycles were one solution to the problem of low-speed stability in early cycles and were typically multi-seat models. Both tandem (in line) and sociable (side-by-side) seating configurations were used.
Historically the most common layout placed the wheels at the corners of a rectangle. An alternative layout had its wheels at the angles of a rhombus (or, more generally, at the angles of a geometric kite). The rhombus layout proved less convenient, because such vehicles were less stable and left three tracks instead of two.
The first experimental steam automobiles were sometimes called steam quadricycles. The Ford Quadricycle was one of the few very early internal combustion cars called motor quadricycles. The terms automobile and car rapidly became universal, supplanting this usage.
Sources of Information
[1] Wikipedia on Quadricycles