THE GEOMETRICAL FOOT

In several different places I have discussed the existence and length of what the mathematicians of the sixteenth century *used*, and those of the seventeenth *talked about*, under the name of the *geometrical foot*, of four palms and sixteen digits. (See the *Philosophical Magazine* from December 1841 to May 1842; the *Penny Cyclopædia*, "Weights and Measures," pp. 197, 198; and *Arthmetical Books*, &c, pp. 5-9.) Various works give a figured length of this foot, whole, or in halves, according as the page will permit; usually making it (before the shrinking of the paper is allowed for) a very…