Hatfield, Robert Griffith, 1815-1879. [from old catalog] · New York & London, Wiley and Putnam · leaf 38
to a b ; join c and b ; bisect c 6 at d—which will be the centre of the circle. If a circle be not too large for the purpose, its centre may veryreadily be ascertained by the help of a carpenters-square, thus :app^ y the corner of the square to any point in the circumference,as at a ; by the edges… … blg. 41. 82.—At a given point in a circle^ to draw a tangent thereto.Let a, {Fig. 41,) be the given point, and b the centre of the cir-cle. Join a and b ; through the point, a, and at right angles toa b, draw c d ; c dis the tangent required.
Carpentry · Architecture
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![An illustration from Cosmographia Francisci Mavrolyci Messanensis Sicvli : in tres dialogos distincta, in quibus de forma, situ numerʹoq[ue] tam coelorum q[uam] elementorum, alijsq[ue] rebus ad astronomica rudimenta spectantibus satis disseritur (1543)](https://img.insideoutlibrary.com/img/200/ia-cosmographiafran00maur-162-0.webp)
