| 摘要 |
The instrument consists of six basic parts: 1. Inclination arm (1) - in order to set the required angle alpha , 2. Inclination arm (2) - in order to secure the angle alpha , 3. Sliding and rotatable rider (3) - in order to provide displaceability and rotatability of the drawing arm (4), 4. Drawing arm (4) - draws the desired ellipse, 5. Rider (5) - which, together with the 6. Support (6), secures the vertical position of the instrument by sliding relative to the drawing surface. If an ellipse is to be drawn in which certain lengths of the two axes of the ellipse are to be observed, the procedure to be adopted is as follows: 1. Insert the inclination arm (1) in the point of intersection of the axes of the ellipse. 2. Set the drawing arm (4) with the drawing point at one of the two end points of the shorter axis of the ellipse. 3. Incline the inclination arm (2) until, after sliding of the drawing arm (4), one of the end points of the longer axis of the ellipse is reached by the drawing point of the arm (4). 4. Slide the rider (5) with the support (6) to the drawing surface and ensure that the instrument remains perpendicular during the working process. The ellipse can then be drawn. <IMAGE>
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