Babbit, Arthur B · New York, H. Holt and company · leaf 201
To draw a tangent to anarc at a point on the arc,when the center is notknown—With the givenpoint A as a center, drawarcs 1 and 2, cutting thearc at B and C. Drawthe chord B C. Throughthe point A draw a lineparallel to B C. (Prob-lem 7.) This Hne will betangent to the arc at thepoint A. PROBLEM 20To…
Mechanical drawing
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from Nicolai Copernici Torinensis De reuolutionibus orbium coelestium, libri VI : Habes in hoc opere iam recens nato, & aedito, studiose lector, motus stellarum, tam fixarum, quàm erraticarum, cum ex ueteribus, tum etiam ex recentibus obseruationibus restitutos: & nouis insuper ac admirabilibus hypothesibus ornatos. Habes etiam tabulas expeditissimas, ex quibus eosdem ad quoduis tempus quàm facillime caculare poteris. Igitur eme, lege, fruere. [Line in Greek] (1543)](https://img.insideoutlibrary.com/img/200/ia-nicolaicopernici00cope-390-270.webp)
