LEVELLING GROUND FOR SLOPES. 



71 



Levelling.— Obtaininq Unifoem Slope. 

 (See text.) 



turf laid or seeds sown. Bowling greens can be made slightly rounding by levelling 

 with soil up to the top of the pegs, in a straight line through the centre, allowing a 

 slight fall at the next row of pegs, or, say, from 1 inch to 2 inches, doubling that 



at the next row of pegs. 



Foi levelling slopes (page 59) 

 the depth at which the pegs are to 

 be sunk can best be arrived at 

 by means 0^ borning-rods. Three 

 of these are required, one placed 

 on the pegs [a) at the highest, 

 and the other at the lowest, point 

 of the slope to be levelled (see 

 Fig. 37), determining the intermediate heights by sighting across the space. In long 

 lengths the borning-rods can also be used for levelling between the pegs, previously 

 fixed at the proper height. Irregular slopes require a certain amount of judgment 

 expended on their levelling, or much labour may be wasted. A reference to Fig. 38 

 (from " The Gardener's Assistant ") should be helpful in showing how to avoid costly 

 mistakes. First find the mean levels of the upper and lower halves of a slope to be 

 levelled, as a h and c d, and the difference of their heights, a d (4 feet). Half the 

 difference marks the position of h I, or the mean level of the whole depth. Measure 

 up 4 feet from I to p, and down from h to /. The line / p will correspond with a 

 slope requiring the least amount of labour to reduce the irregular surface, shown by 

 the curving line, to a gentle uni- 

 form slope. The rising ground, 

 a, has only to be turned into the 

 hollow at h, and that at c into 

 the sunken space at d. If a 

 steeper slope is desired, more soil 

 will have to be moved from the 

 lower projection to the highest 

 point, reversing these conditions 

 in the event of a more gentle fall than that shown in the diagram being preferred. 



It is not merely where perfect levels and well-graduated slopes must be formed 

 that levelling instruments should bo used, but they are required for all parts of a 



Fig. 38. Obtaining Level (A /) and Slope (i p). 

 The curved line indicates the original irregular surface. 



