220 



Commercial Gardening 



In the diagram it will be noticed that the dotted line hi represents 

 the level, and it may be seen that there is just enough ground above this 

 line to fill up the hollows beneath it and thus make the surface perfectly 

 level. If it is desired to lay out ground on an inclined plane, instead of 

 perfectly level, a rod is placed at each end, and one in the middle, as 

 shown at A, G, and D, respectively. The line ip will represent the inclined- 

 plane surface, and the point at D being in the middle will remain in the 

 same position on the surface. From the diagram it is obvious that it 

 would not be necessary to move as much soil to fill up the hollows below 

 the line ip as it would to fill up beneath Id. The levels between A D and 

 D G should be taken in the way already described, making A and D 

 extremities in one case, and D G extremities in the other. In this way 

 a good deal of labour in shifting soil afterwards would be saved, as the 

 hollow places would be indicated by the section in the field book. 



In connection with ordinary land surveying for horticultural and 

 agricultural purposes one need not consider such problems as the curva- 

 ture of the Earth's surface, nor is there any great need for the use of 

 the theodolite and trigonometry, or logarithmic tables. 



LAYING OUT LAND AND PLANTING 



It often happens that ground is to be laid out in squares, rectangles, 

 &c., of different dimensions, and it may be well to give a few instructions 

 and illustrations. 



The Square. If an acre of land is to be laid out in the form of a 

 square, each side must measure 316^ links of Gunter's chain = 208 T ^\j- ft. 

 = ^Ttfu yd. A popular method of marking out a square acre is to step 

 out 70 paces each way. 



The following tables may be useful to show the dimensions of an acre 

 in perches and feet, and also in yards: 



TABLE SHOWING BREADTHS AND LENGTHS or A STATUTE ACRE 

 IN PERCHES AND FEET 



