The circles of proportion and the horizontal instrument The former shewing the maner how to work proportions both simple and compound: and the ready and easy resolving of quæstions both in arithmetic, geometrie, & astronomie: and is newly increased with an additament for navigation. All which rules may also be wrought with the penne by arithmetic, and the canon of triangles. The later teaching how to work most quæstions, which may be performed by the globe: and to delineat dialls upon any kind of plaine. Invented, and written in latine by W.O. Translated into English, and set out for the public benefit, by William Forster.

Abstract

W.O. = William Oughtred. Another issue, with cancel letterpress title page, of STC 18899: The circle of proportion, and the horizontall instrument. Translated by William Forster from the original Latin. The "additament" also published separately as STC 18899c: An addition unto the use of the circles of proportion. Reproduction of the original in the Bodleian Library.