Journal of Agriculture , Victoria. 



[lo Feb., i9ir. 



spaced 15 feet apart, are sufficient as outlets for irrigating lucerne, and 

 when watering orchards, one for every row of trees in fairly stiff soils ; 

 the irrigator will soon find the size and spacing best adapted to his par 

 ticular circumstances. 



of Bonk b C 



51. LONGITUDINAL SECTION OF HEAD DITCH WITH FALL. 



Where it happens that a head ditch has to follow the fall of the 

 country, it should be constructed like a series of steps with long treads 

 and short rises, or in this case " falls," as in No. 51, a suitable check being 

 fixed at the points a, b, c, &c. There is no need to excavate the ditch to this 

 staircase section. So long as the checks are properly fixed, the water will 

 usually scour the bed to a normal condition. The greater the surface fall 



52. CHECK IN HEAD DITCH SHOW'ING POSITION OF SAPLING. 



the greater the number of checks and, with a slight inclination, the converse 

 is the case. If the ditch simply conveys water for the supply of some 

 subsidiary ditch, the checks should be made deep, and consequently few, 

 but if acting as a head ditch solely, the steps should be successively from 

 4 inches to 6 inches lower, but much depends on the nature of. the ground 

 and the purpose for which it is used. 



SAPLING AND BAG CHECK 

 OR REGULATOR. 



54- 



SAPLING REGULATOR IN 

 POSITION. 



The simplest and cheapest form of check is made of a sapling and 

 bags ; substitutes will readily suggest themselves. The sapling should be 

 about 2 inches in diameter and long enough to reach well across the banks 

 and. preferably, should be slightly curved in the centre (No. 52). The bags 

 should be sewn together, and one edge of the cloth thus made nailed to the 

 sapling and wound once or twice around it (No. 53). The ends of the sap- 

 ling are bedded in the banks of the ditch to such depth as may conveniently 

 deal wdth the water ; and the cloth is stretched along the upstream bed of 

 the ditch and kept in position with a few shovels of earth thrown in on top 

 along its edges, to prevent any escape of water beneath (No. 54). Such 

 checks will be found very effective in practice, and are readilv removable 

 from place to place as desired ; but it must be understood that where the 

 fall of the ditch is so considerable as to set up excessive scour some per- 



