Sesquitertium
Sesquitertium refers to the improper rational fraction
- <math> {4 \over 3} = 1 + {1 \over 3}. <math>
It is a superparticular number.
The sesquitertium in musical harmony is the ratio corresponding to the interval diatessaron.
In visual harmony, the sesquitertium can be the ratio between the length and the width of a rectangle. For example, a 16 inch CRT monitor whose length is 13 inches and whose width is 9.5 inches has a length-to-width ratio of 1.368 which is close to a sesquitertium, 1.333, with an error of +2%.
See also: sesquialterum, sesquiquartum, sesquiquintum.
