General Instructions. 



whole width at one trench. But, if the piece of ground 

 hf large, it will not be worth while to carry the earth of 

 the first trench away. It may be disposed of by throwing 

 it back, over the ground about to be trenched. 



15. Let us suppose a piece of ground containing an 

 acre, and, the rules for trenching such a piece will apply 

 to a piece of any extent. It would, in such a case, even 

 if tlie outsides were all straight lines, be inconvenient to 

 open at once, so long a trench as would reach from one 

 side to the other. The trench might be in length propor- 

 tioned to the number of workmen, allowing about half a 

 rod to each, so as not to crowd them too much. Suppose 

 the piece of ground to be 13 rod, or perch, long, and 12 

 rod wide, which piece will then contain one acre all but 4 ^z- 

 rod. Let us suppose the sides to be straight, and that four 

 men are to trench this piece of ground. 



16. First mark out the piece into lifts ; that is to say, 

 into strips of the width that the men are to trench at a time. 

 They are called lifts, because men are said to carry so much 

 ground, or space, in their works of the field or garden. 

 A mower, who takes a wide swarth, is said to carry more 

 ground than he who takes a narrow one. Any width of 

 ground that is dug, or hoed, at once going along, leaving 

 the rest of the fiehl to be worked on in like manner, is, 

 therefore, called a lift; and it is necessary to bear the 

 word in mind. There must be some word to designate 

 the thing, and this is as good as any other. 



17. The supposed piece of ground is 12 rod wide and 13 

 long. Doing the work longwise there will be 6 lifts each of 

 2 rod wide ; and this piece, marked out into lifts, let us 

 suppose to be represented by the following lines, which are 



