Nystrom, John W. (John William), 1824-1885 · Philadelphia, J.B. Lippincott · leaf 96
47. To construct a Parabola. Given the axis of ordinate P, and vertex A.Take A as a centre and describe a semicirclefrom B which gives the focus of the parabola at/. Draw any ordinate y at right angle to theabscissa A x, take a as radius and the focus/as a centre, then intersect the ordinate y, bya… … To draw an arithmetic spiral.Given the pitch p and angle v, divide theminto an equal number of equal parts say 6.make 01=01, 0 2=02, 0 3=0 3, 0 4=04, 05=0 5,and 0 6=the pitch p; then join the points 1, 2,3, 4, 5, and 6, which will form the spiral re-quired. Circle. CIRCLE. The periphery of a circle…
Mechanical engineering · Engineering
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