The first consideration is to grade the land. Grading is very expensive, especially if performed at a season when the soil is heavy with water. Every effort should be made, therefore, to reduce the grading to a minimum and still secure a pleasing contour. A good time to grade, if one has the time, is in the fall before the heavy rains come, and then allow the surface to settle until spring, when the finish may be made. All filling will settle in time unless thoroughly tamped as it proceeds.
The smaller the area the more pains must be taken with the grading; but in any plat that is one hundred feet or more square, very considerable undulations may be left in the surface with excellent effect. In lawns of this size, or even half this size, it is rarely advisable to have them perfectly flat and level. They should slope gradually away from the house; and when the lawn is seventy-five feet or more in width, it may be slightly crowning with good effect. A lawn should never be hollow,--that is, lower in the center than at the borders,--and broad lawns that are perfectly flat and level often appear to be hollow. A slope of one foot in twenty or thirty is none too much for a pleasant grade in lawns of some extent.
In small places, the grading may be done by the eye, unless there are very particular conditions to meet. In large or difficult areas, it is well to have the place contoured by instruments. This is particularly desirable if the grading is to be done on contract. A basal or datum line is established, above or below which all surfaces are to be shaped at measured distances. Even in small yards, such a datum line is desirable for the best kind of work.