Articles are occasionally required to be made up in the form of an egg-shaped oval; hence a knowledge of how to describe that figure will be useful to a sheet and plate metal worker. The con-struction, which should not be difficult to follow, is shown in Fig. 123. The long diameter is first marked down and the point O obtained by making A O equal to half the width of the oval. The short diameter, C D, is drawn at right angles to A B passing through the point O. A semicircle is then described upon C D. Join B to D and make E F equal to O C by running round the dotted curve and line, as on the figure. Cut off B P equal to D E, and so fix the point P for the centre of the end curve. Join P to E and bisect the line P E in H. Draw H Q square to E P, thus obtaining the centre, Q, for the side curve. Join Q to P and produce to K. The line Q D will now be used as the radius for the side curve and P B for the end curve, both of these curves meeting in K. The object of putting in the line Q K is, of course, to determine the meeting-point of the side and end curves. If the construction is carefully carried out there should be no difficulty about the curves meeting at the point K.

Hip And Sponge Baths Egg Shaped Oval 138

Fig. 123.