I20 



POPULAR GARDENING. 



March, 



fectly even so that the level might be 

 freely turned upon It. This frame was sup- 

 ported by light stakes vrith shoulders at the 

 top upon which the frame rested, being se- 

 cured thereto by nailing. The frame work 

 having been set on the ground at I (see also 

 Fig. 3) the stakes were made to enter the 

 earth by careful driving, for firmly steadying 



surface, yet at ten feet further back the 

 height to the datum-line was but 3 ft. 6 in. 

 A still higher point on the bank was at D, 

 where the measure from the soil to the line 

 was but 3 ft. 11% in., as seen by the table. 



The Fall and Depth of Drains. As the 

 creek's level is amply low to give any de- 

 .sired fall to the drains, it was determined to 



Levelling the Bottom and Laying the 

 Tile. After having located the ditch bot- 

 tom at its outlet as previously described, it 

 next followed to secure the uniform rise of 

 X inch to the rod decided upon throughout. 

 This was done with the greatest ease by the 

 use of the inexpensive level of Fig. 6, con- 

 structed by our carpenter. It was made of 



Fig. 3. Determining the Datum-Line at various Pmnts oiicr Hie Place with Measuring Bod, and Sighting over the Level at T. 



it, and then as a finishing touch to have its 

 upper surface come exactly level, as shown 

 by the carpenter's level which was turned 

 in all directions on it as the stake-driving 

 progressed. 



The D.\tum-Line. Now the object of thus 

 locating a level at / (Figs. 1 and 3) was to 

 establish what is termed a datum-line or 

 level over the area to be drained, from which 

 to calculate the comparative height of the 

 surface throughout, as well as the depth of 

 the drains. The datum-line at I being rep- 

 resented by the upper surface of the carpen- 

 ter's level, it is evident that inasmuch as the 

 top of the frame (Fig. 3) was perfectly level 

 the entire range, embraced by sighting 

 over the level's top as it was turned in all 

 directions would represent an exact level, 

 hence the desired datum-line, throughout. 

 In all such cases there is nothing arbitrary 

 as to the height of the datum-line, so long as 

 It is convenient. 



To make the datum-line available for use, 

 it was needful to locate its height above the 

 siirface at numerous points over the place. 

 The points chosen were along the main 

 drain and at the outskirts of the part to be 

 drained, as indicated by letters yl to If in 

 Fig. 1. In Fig. 3 is shown how the levelling 

 was done. It is seen that one man did the 

 sighting over the level at /, while an attend- 



Fig. 3. The Level set up; Sighting over it. 



ant held a measuring pole successively at 

 the various 'points, and marked on a map 

 the height of the datum-line, as determined 

 by the sighting, above the surface. A per- 

 manent stake was also driven at each point, 

 the top to be even with the datum-line. In 

 this engraving the attendant is shown at 

 the point C (see also Fig. 1), and as having 

 moved to F and H respectively. The record 

 of the datum-line measurements from the 

 surface upwards at the different points is 

 given in the first horizontal line of the table 

 presented on this page. It may be said that 

 while the measuring pole held at A (at a 

 point partly down the creek bank) showed 

 the datum-line to be 6 ft. 2 in. above the 



start these with a depth of ditch of 3 ft. 6 in. 

 at H, the point farthest from the outlet (A), 

 and then to secure a uniform fall of Jf inch 

 to the rod throughout. The proper place of 

 beginning the work being at the outlet, it 

 was easy to compute the level for the ditch 

 bottom at this point as follows: 



It is to be observed by the table annexed 

 that the datum-line at H was .5 ft. 3 in. 

 above the surface of the soil. Now as the 

 tiles are to be 3 ft. 6 in. in the ground here, 

 it is clear that the drain bottom here must 

 be 3 ft. (! in. plus .5 feet 3 inches (7 ft. 9 in.) 

 below the datum-line. And as the distance 

 in rods from H along the course of the 

 drain to the desired outlet A was found to 

 be 70 and the fall to be }-.2 inch per rod, so 

 the ditch bottom at A must be 35 inches 

 lower here than at H, or 10 ft. 8 in. below 

 the datum-line. The surface at A where 

 the measuring pole was held is seen by 

 the table to have been 6 ft. 3 in. below 

 the datura-line, so that to start the drain 

 rightly on the above computation it is seen 

 that the ditch bottom was to be exactly 4 ft. 

 6 inch below the soil's top,and so it was made. 



By the heavy lines in Fig. 1 is shown the 

 general arrangement of the drains, the dis- 

 tance apart being 40 ft. for the laterals and 

 the depth below the surface from 3 ft. *! in. 

 upwards, as shown by the lower horizontal 

 line of figures in the table. With having 

 the proper level of the ditch at its outlet, or 

 point of starting the digging, it followed that 

 with all tile then having been laid by the 

 rule of a rise of 

 work proceeded 

 inwards a perfect 

 fall was the result, 

 this fact being 

 shown by the free 

 flow of the water Depth of the Ditch 

 from the drains 

 after the season's 

 work was completed. 



Digging the Ditches. Previous to dig- 

 ging, the lines were staked off according to 

 the plan of Fig. 1. The tools used were such 

 as can be had of most implement dealers, 

 and are shown by Fig. 4. The common spade 

 was used for "topping" the ditch, while 

 the narrow one cut the ditch down to its 

 approximate depth, as determined at each 

 stake left for indicating the datum-lines at 

 points marked by letters on Fig. 1. The 

 hoe-like or bottoming scoop formed the bed 

 for the tile; the digger throwing out the 

 dirt as clean as possible with his spade for a 

 space of half a rod or so, then cleaning the 

 bottom with the scoop which he drew to- 

 wards him. These draw scoops come in dif- 

 ferent sizes to fit the tile to be used. Fig. .5 

 shows an iron that fits the sole of the dig- 

 ger's boot against the heel, to protect the foot 

 in driving the spade into the hard under- 

 soil. With such tools the workmen were 

 able, in the somewhat firm soil of this farm, 

 to throw out a ditch 4 feet deep and being 

 not more than a foot wide at the top. 



', inch to the rod as the 



FROM DATCTM-LINE 



A 



ft. in. 



ToSoll 6.2, 



To Bottom of Drain. 10.8, 

 4.6, 



( 



an inch board one rod in length and nine 

 inches wide at one end (b) and a half inch 

 narrower (equal to the fall for one rod) at 

 the other end. At the center (c) a .small 

 spirit level was attached to the top by 

 screws, being protected by a block at each 

 end. To use this device it was only neces- 

 sary to apply it to the ditch bottom with the 

 wide end towards the outlet, and when the 

 bubble indicated that the top ot the board 

 was level, its bottom edge resting evenly on 

 the ditch bottom, it was obvious that the 

 ditch for this rod had the desired one-half 

 inch fall towards the outlet, and so of every 

 part ot the main and the lateral drains sim- 

 ilarly treated. If the level showed insuffic- 

 ient fall the draw scoop 

 brought in play soon 

 shaved the bottom 

 enough to produce it. If 

 shaved too deep a quan- 

 tity of soil returned eas- 

 ily remedied the defect. 

 Another style of level 

 is shown by Fig. 7 directly over the former 

 one, in which a plummet attached to the 

 central upright is used to procure the proper 

 level instead of using a spirit level as in 

 the former one. By marking, for further 

 guidance, the position of the plummet when 

 one end of the level (16} .< feet long) is raised 

 one-half an inch, there is no ditBculty in 

 securing the same results with this level 

 as with the other. 



Following immediately on levelling the 

 bottom the tile were laid, working from the 



Fig. 5. Boot Iron used 

 in IHgging. ■ 



B 



ft. in. 



.5.7, 



10.1, 



4.6, 



C 

 ft. in. 

 4.11, 



9.6, 



4.7, 



D 

 ft. in. 



3.11M, 



E 

 ft. in. 



5.1H, 

 8.2H. 

 3.1, 



F 



ft. in. 



5.6, 



8..5, 



3.U, 



G 



ft. in. 

 5.6, 

 9.3, 



3.7, 



H 

 ft. in. 



5.3, 

 7.9, 

 2.6, 



Table showinn Measurements from the Datum-line, Secured at the 

 various Points indicated in Figure 1, by Letters. 



surface by using a six foot pole having a 

 piece of X inch iron rod, one foot of which 

 was turned at right angles, fastened into 

 the end with which to handle a section of tile, 

 and firmly placing each one in its proper 

 position. This last operation, next to shap- 

 ing the bottom, is the most important point 

 in the laying of drains, and one on which 

 largely rests its permanent value. All the 

 joints were made as close as possible and 

 the junction of the laterals with the mains 

 were protected by placing over them pieces 

 of tile. Where in any case the bottom was 

 so soft that the tile did not lay firmly, a thin 

 layer of straw or similar material was 

 placed beneath them. As fast as the tiles 

 were laid a covering of soil at least a foot 

 deep and well packed was put on to keep 

 them in place, the filling having been com- 

 pleted at our leisure. In our work six inch 

 tile, inside measure, were used for the first 

 half, and four inch tile for the last half of 

 the main, and two inch tile for the laterals 

 throughout. The laterals having the great- 

 est length were 43 rods long. 



