Hatfield, Robert Griffith, 1815-1879. [from old catalog] · New York & London, Wiley and Putnam · leaf 56
upon e, with e a for radius, describe the semi-circle, a d PRACTICAL GEOMETRY. 41 c; at h, erect h d, at right angles to a c; then b d will be themean proportional between A and B. For an application of this problem, see Art. 105. CONIC SECTIONS. 111.—If a cone, standing upon a base that is at… … €one be cut by a plane in the direction, e/, the section will bean ellipsis ; if in the direction, m, I, the section will be a para-bola ; and if in the direction, r o, an hyperbola. (See Art. 56to 60.) If the cutting planes be at right angles with the plane,a 6 c, then— 112.— To find the axis of…
Carpentry · Architecture
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![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-340-231.webp)
