. A textbook on mechanical and electrical engineering . Fig. 53 Construction.—In Fig. 56, letB D, the long diameter, or majoraxis, which is 3V long, and A C, the short diameter, orminor axis, which is sy long, intersect at right anglesto each other in the center O, so that D O = OB and A O= O C. With 6> as a center, and (9 C as a radius, describea circle; with the same center, and O D as a. radius, describeanother circle. Divide both circles into the same number ofequal parts, as 1-2, 2-3, etc. This is best done by firstdividing the larger circle into the required number of parts, beginning
. A textbook on mechanical and electrical engineering . Fig. 53 Construction.—In Fig. 56, letB D, the long diameter, or majoraxis, which is 3V long, and A C, the short diameter, orminor axis, which is sy long, intersect at right anglesto each other in the center O, so that D O = OB and A O= O C. With 6> as a center, and (9 C as a radius, describea circle; with the same center, and O D as a. radius, describeanother circle. Divide both circles into the same number ofequal parts, as 1-2, 2-3, etc. This is best done by firstdividing the larger circle into the required number of parts, beginning at the center lineA C, and then drawing radiallines through the points ofdivision on this circle, to thecenter O of the circles, asj^ shown in the upper right-handquarter of the figure. Theradial lines will divide thesmaller circle into the samenumber of parts that the largerone has been divided the points of divisionon the smaller circle, draw horizontal lines, and, throughthe points of division on the larger circle, draw vertical. Pig, 56 44 GEOMETRICAL DRAWING §13 lines; the points of intersection of these lines are points onthe ellipse. Thus, the horizontal line Sc and the verticalline 3 c intersecting at c give the point c of the a curve through the points thus found by placing anirregular curve on the drawing in such a manner that oneof its bounding lines will pass through three or more points,judging with the eye whether the curve so traced bulgesout too much or is too flat. Then adjust the curve again,so that its bounding line will pass through several morepoints, and so on, until the curve is completed. Careshould be taken to make all changes in curvature as gradualas possible, and all curves drawn in this manner should bedrawn in pencil before being inked in. It requires con-siderable practice to be able to draw a good curved line inthis manner by means of an irregular curve, and the generalappearance of a curve thus drawn depends a grea
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmechani, bookyear1902
