e arc a d b. On d, withD A or D B as radius, describe the arc a e b.Then the intersection e will be the centre,and E A or E b, the radius of the circle whichwill contain a b the number of times requiredfor an octagon. * problem XXVI. To describe a regular nonagon on a givenline. Bisect A B in c.… … the point f will be the centre of the nonagonvery nearly. (To be continued.) To Remove Ink, Oil, and Grease StainsFROM Books, &c.—Oxymuriatic acid removes,perfectly, stains of ink ; and, should the paperrequire bleaching, the operation will answerboth ends at the same time. Nearly all theacids…
Design · Decoration and ornament · Art
Internet Archive · Smithsonian Libraries · 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-397-275.webp)
