Gould, Lucius D., b. 1814. [from old catalog] · New York, A.J. Bicknell & co. · leaf 52
e found by setting off each way from B, half the width of therail, from the point N, set off each way half the length of 6 5, Fig.4; then 4 5 and 6 7 are the points from which to draw the curves. Thepoints for the pins are found by taking in the compasses C 5 as radius, fromthe point 6 as centre,… … Plate 12 Exhibits the ground plan and elevation of the platform, for an acute angledstaircase; the wreath in one piece; the plank sawed square to a parallelwidth. To find the length of the major axis of the elliptic curve for the centreof the mould, draw lines from the points A and J, Fig. 1,…
Stair building
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