The American house carpenter: a treatise upon architecture, cornices and mouldings, framing, doors, windows and stairs. Together with the most important principles of practical geometry (1852)
Hatfield, R. G. (Robert Griffith), 1815-1879 · New York, J. Wiley · leaf 60
fg and g f show the position of the string when the pencil arrives at g. This method, when performed correctly, is perfectly accurate;but the string is liable to stretch, and is, therefore, not so good touse as the trammel. In making an ellipse by a string or twine,that kind should be used which… … 116.— The axes being given, to describe an ellipsis mith atrammel. Let a b and c d, {Fig. 81,) be the given axes. Placethe trammel so that a line passing tlirongh the centre of thegrooves, would coincide with the axes ; make the distance fromthe pencil, e, to the nut,/, equal to half c d ; also,…
Carpentry · Architecture
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