| 摘要 |
Drafting instrument for drawing ellipses using scribe arm and members capable of being pivotally connected at two points along the scribe arm, one of the members being constrained to move along a straight line congruent to the minor axis and the other of the members being constrained to move along a straight line congruent to the major axis, as the members reciprocate along their respective lines, a point of the scribe arm describes an ellipse.
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