INSTRUMENTS FOB LEVELING. 



197 



along such work as irrigating canals and embankments it 

 may be placed upon a three cornered plate of iron, or a 

 trivet, standing upon three pins, by which it may be firm- 



Fig. 84. GURLEY S LEVEL. 



ly set upon a piece of wood, earth, or a stone. A tripod 

 and the trivet is furnished with the level by the makers, 

 for the very reasonable price of $35. A leveling rod with 

 target is $5 extra. 



An instrument much used by French irrigators is thus 

 made : Two pieces of 

 wood, r| 2 inch wide 

 by 1 inch thick and 10 

 feet long, are pinned 

 together at one end, 

 forming an angle, the 

 base of which spreads j 

 exactly 16 1 1 2 feet. This 



Fig. 85. HOME-MADE LEVEL. 



gives a hight of the apex or joint from the ground 

 of about 5 1 | a feet. The arms are fixed in their proper 

 position by a cross-piece at about 3 l \ z feet from the base, 

 and fixed exactly parallel to it. The end of each arm is 



