Mensuration, also known as mensural notation (possibly from the Latin musica mensurata, "measured music"), is a system of rhythmic relationships created by European composers in the 13th century. From the system of mensuration came what we now know as the time signature and use of bars in modern music.<br><br>Mensural notation very much resembles the modern rhythmic notation. The mensural brevis is the predecessor to the modern double whole note (breve); likewise, the semibrevis corresponds to the whole note (semibreve), the minima to the half note (minim), the semiminima to the quarter note (crotchet), and the fusa to the eighth note (quaver). Mensural notation also used smaller subdivisions, such as the semifusa which corresponds to the sixteenth note or semiquaver. On the other hand, there were also two larger values, the longa (quadruple whole note or long) and the maxima (or duplex longa, called a large in Britain), which are no longer in regular use today.<br>