Sullivan, Christine [Gordon]. [from old catalog] · New York, Cincinnati [etc.] American book company · leaf 13
Fig. 4. — Regular Curve. Fig. 5. — Irregular Curve. 5. Surface has length and breadth without thickness. 6. \ plane surface is a flat, even surface. 7. Parallel lines are lines that will not meet, no matter how farproduced. They lie in the same plane.
Mechanical drawing
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