41 



14 



THE BOOK OF GARDENING. 



a similar result simply with the aid of a garden line and 

 a few pegs. 



(i) To trace with the line a straight line perpendicular to 

 another straight line (Fig. 9) : On the line A B two pegs are 

 inserted at E, F, at equal distances from the centre (C) ; nooses, 



. D E 



Dr' 



A 



Jl. 



B 



A 



B 



Fig. 9. — Tracing a Perpen- 

 dicular AND an Equi- 

 lateral Triangle with 

 A Garden Line. 



Fig. 10. — Tracing a Perpendi- 

 cular at the Extremity 

 OF A Straight Line with 

 A Garden Line. 



formed at each extremity of the garden line, are passed over 

 E and F, and in the middle of the line a knot is made. By 

 holding the line at D and tightening it, DC, the perpendicular to 

 AB, is found. A similar result may be obtained by tracing a circle 

 from each extremity of the line AB, with radius EF. The two 

 arcs of the circles will meet in D, from which the perpendicular 

 to AB may be traced to C. This latter method can be used 

 to advantage on a fiat surface, while the former is preferable on 

 uneven ground. 



(2) To trace a perpendicular at the extremity of a straight line 

 (Fig. 10) : In the line AB a peg (C) is inserted anywhere, and 

 the nooses of the garden line are passed over the pegs B, C. 



c 



Fig. II. — Tracing a Triangle. 



Fig. 12. — Tracing a Rectangle. 



This is draw^n tight till the knot made in the middle gives the 

 point D, where another peg is inserted. The noose over the 

 peg B is then taken off, and by putting it in a line w^ith DC 

 the extremity of the garden line will give the point E, the 

 hne from which to B is perpendicular with AB. 



