Hackney carriage a 1662 Act of Parliament establishing the Commissioners of Scotland Yard to regulate them. Licences applied literally to horse-drawn carriages, later modernised as hansom cabs (1834), that operated as vehicles for hire. The 1662 act limited the licences to 400; when it expired in 1679, extra licences were created until a 1694 act imposed a limit of 700, which was increased by later acts and abolished in 1832. There was a distinction between a general hackney carriage and a hackney coach, a hireable vehicle with specifically four wheels, two horses and six seats, and driven by a "Jarvey" (also spelled
Horse-drawn vehicle by a pair (or by a team of several pairs) have a "pole" which attaches between the wheel pair. Other arrangements are also possible, for example, three or more abreast (a "troika"), a wheel pair with a single lead animal (a "unicorn"), or a wheel pair with three lead animals abreast (a "pickaxe"). Very heavy loads sometimes had an additional team behind to slow the vehicle down steep hills. Sometimes at a steep hill with frequent traffic, such a team would be hired to passing wagons to help them up or down the hill. Horse-drawn carriages have been in use