i8 7 9.] 



LESSONS IN DRAWING, ETC. 



33 



of stout sheet-iron, fixed into one leg and passed through an opening 

 in the other, as shown, with a thumb-screw to fix it at any desired 

 radius. The other leg of the compass should 

 be reduced to a point, and shod with iron to 

 keep it from wearing or getting broken. The 

 beam-compass is an article which any gar- 

 dener, with a little assistance from a black- 

 smith, may make for himself. Get two iron 

 rods, 2 feet long and J inch thick — similar 

 to those shown at a b, fig. 60 — pierced with 

 small holes 3 inches apart. The rod a 

 should have a thickish shoulder worked 

 upon it, some 6 or 8 inches from its point, 

 for the double purpose of steadying it in 

 the ground and supporting the lath or beam 

 part of the compass. Eod b should be made 

 with a sharp point for tracing out figures 



on the ground. The lath should be 10 



Fig. 59. 



thick. Mark this off 

 garden measuring- rod, 



or 12 feet long, 2 inches wide, and 1 inch 



into feet and inches after the manner of a 



and get it pierced with holes the same size as the iron rods at every 



inch of its length, so that rod a may be shifted to any desired point. 



These holes will not have to be made in one row along the centre of 



the lath, but in two or three rows, zigzag fashion, as there will be 



T 



T 



Fig. 60. 



less chance of the lath splitting in two. By placing a short piece of 

 stout wire through the hole nearest to the point of rod b, after pass- 

 ing it through the lath, it will prevent the latter from slipping off 

 while the circle is being described by swinging it round by the handle 

 of the rod. A similar piece of wire placed through either of the 

 holes in rod a will serve to support the lath farther from the ground, 

 should anything intervene between the centre of the circle and the 

 circumference to make that necessary. It will of course be under- 

 stood that in marking off the feet and inches on the lath, the measure- 

 ment must start from the first hole, or that through which the rod a 

 is to be placed. 



Both these forms of compasses have a fault — their radii are 

 limited. The simplest of all compasses for ground work, and which 



