The inch is a subsidiary unit of length in the British Imperial system, defined as 1/36 yard. The British Imperial system of units was established on June 17, 1824, by the Weights and Measures Act. Strictly speaking, it is not correct to use the term British Imperial for units in use before that date, and they are better described as traditional British. In this system, the standard yard had a length of 0.914398416 m, making the inch equal to 0.025399956 m. (Cardarelli gives a value of 0.91443992 m, but this is in error.) For the detailed history of this yard, see Yard (British Imperial).