Licks, H. E · New York, D. Van Nostrand company · leaf 156
APPENDIX 147 groove and thus the point E moves in the straight line EA. Euclid's postulate that a straight line can be drawn gives no information as to how this may be done. It is usually- supposed to be drawn by means of a ruler, but then the question arises as to how the ruler has been made… … Fi'g.60 CDEF is jointed at the corners, and the radius arm BC is one-half of the distance CA, and A is also a fixed point which is connected with the parallelogram by the rods AD and AF. Thus the circular motion of C causes the right-line motion of E. Since there can be no doubt about the circle,…
Mathematical recreations
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