Rogers' drawing and design; an educational treatise relating to linear drawing; machine design; working drawings; transmission methods; steam, electrical and metal working machines and parts; lathes; boiler and parts; instruments and their use; tables, etc (1913)
Hawkins, N. (Nehemiah), 1833- · New York, T. Audel · leaf 25
Fig. 42. Straight line is called the Directrix, and the fixedpoint is called the Focus of the parabola ; a straightline drawn at right angles to the directrix, and pass-ing through the focus, is called the Axis. … A Hyperbola is a curve from any point of which,if two straight lines be drawn to two fixed points,their difference shall always be the same. SeeFig- 43- ^ Fig. 44. An Mllipse is a curve, described by a point, mov-ing so, that the sum of its distances from two fixedpoints is always constant; the two…
Mechanical drawing · Machine design
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