GARDEN GEOMETRY 



411 



tained by combining a semicircle with a semi-ellipse, 

 as indicated in the accompanying illustration, (Fig. IV). 



The ellipse is described in the following way: Stretch 

 two cords A B, C D, at right angles to each other, and 

 mark off the lengths O E, O F, each equal to half the 

 length of the required ellipse, and O G, O H, each equal 

 to half the width of the same. From H measure HI 

 and H J, each equal to O E. Drive pegs at I, H, and J, 

 and stretch a cord from I round H to J, having loops at 

 I and J. Remove the peg H and the other cords, and 

 inserting the scriber in the bend of the cord joining I 

 and J, move it round from E to F, via H, keeping the 

 cord taut, when its point will describe one half of the 

 ellipse. Reverse the position of the knife, and work 

 round in the opposite direction, via G, and the ellipse 

 will be completed. 



'Fig. V Fig. VI Fig VII 



The Hexagon. — Describe a circle as above directed, 

 and with the tape mark o£F the points A, B, C, D, E, F 

 on the circumference so that the distance from each 

 point to the next one, in a straight line, is equal to the 

 radius of the circle. See Figure V. 



Right Angle. — When working on a large scale it is 

 not practicable to use a square when setting out a right 

 angle, and the following is the best method: If, in Figure 

 VI, it is required to mark out a line from the point A 

 in the line A B at right angles to A B, measure from A to 

 C a length of three yards, or feet, or any convenient 

 unit. From C as centre describe an arc of radius equal 



