164 



Improved System of Irrigation. 



means of the plumb-line 3 ; mark the place of No. 1 ; then 

 advance the level bj putting No. 1 in the place of No. 2, and 

 finding a new place for No. 2 by means of the plumb ; and so 

 proceed until you have made a level line across the meadow, 

 subject, however, to certain variations, which I shall explain as 

 occasion may require. Let some person follow with a spade 

 or something of the sort, and turn up a bit of sod at every alternate 

 move of the level, by which means you will have a bit of sod as 

 a mark, at about every JO feet. Begin say at B, fig. 1, and 

 proceed as directed, and on a flat piece of ground you will pro- 

 bably produce a line thus, B C. The arrows marked on the 

 line show the way the water is to be made to run on in the 

 gutter line ; to obtain which you must deviate from precise 

 levelling, and allow the plumb-line to drop a little before the 

 level mark when you are inclining doivn the meadow, and a little 

 behind it when you are inclining up the meadow. This will 

 have the effect of running the water out of the low places, and 

 upon the high places. Care must be taken in levelling to follow 

 out the indications of the level, however crooked and curved the 

 line might appear ; and by all means to go doim around every 

 elevation, and to avoid every disposition to cut the line straighter, 

 &c., as every straight cut that is made of that sort will have the 

 effect, more or less, of causing a dry spot below the gutter, or a 

 pond above it. 



Having completed that line, return to the side you first began, 

 and by no means level backwards. Return, say to D, which 

 should be about 10 paces down from B ; and by proceeding as 

 in B C, you will very likely produce the line D E. The con- 

 sequence will be, that C and E are too far asunder ; you must 

 therefore begin at F, and produce the line F G. I have sup- 

 posed the middle of the meadow to be lowest, and the meadow 

 itself tp he flat ^ rising on each side of the middl e by two gentle 

 undulations, requiring the lines of gutter to curve very con- 

 siderably. The nature of the ground is supposed to make it 

 necessary now to begin at H, and to produce H I. It will now 

 be perceived that D and I are too far asunder, making it necessary 

 to introduce K L, beginning at K. Then proceed to finish out 

 the higher side in like manner. 



To avoid crowding the figure, I shall draw it anew, with a few 

 alterations introduced for the purpose of showing the next process 

 to advantage. 



Let fig. 3 represent a meadow, with all the lines of fig. 1 

 marked with the level and ploughed, but not " turned out ;" the 

 lines will be sufficiently perceptible to manage the next pro- 

 ceeding. It will be perceived that the curves of the lines form 

 a series of loops, and that the undulations of the meadow are 



