380 



SCIENCE OF GARDENING. 



Part II. 



ations ; the removal and disposal of the earth, the formation of the bed and margin, and 

 the formation of the dam or head and sluice. 



1 946. In the removal and disposal of the earth, regard should be had to preserve the 

 best soil for what is to be future surface ; and, in poor lands, it may often be advisable 

 to dig or pare off the surface of the spots to be covered by the excavated earth, and 

 preserve them for the same purpose. Where the new soil is to be thinly scattered over 

 the old, fallowing, trenching, or digging may effect the proper mixture. When large 

 masses of new earth are to be laid down, that of worse quality must be farthest removed 

 from the probable reach of the roots of future trees ; or, if the roots of trees will pene- 

 trate the whole mass, then the whole soil should be mixed. Gravelly materials should 

 be kept at such a distance from the margin of the water, as not to act as a drain 

 from it ; and, in forming the mass of earth requisite at most dams or heads, the less 

 gravel or porous matter used alone, the more compact and retentive will be the head. 

 In every mode in which excavated earth is disposed of, care is requisite to blend its out- 

 lines with those already existing, so as to avoid all appearance of patches laid on, bumps, 

 warts, or excrescences, than which nothing is more disagreeable in surfaces. 



1947. In the formation of the bed, where the excavation has been made in a level sur- 

 face, no farther attention is requisite than attending to the depths indicated in the design, 

 which will generally be greatest towards the middle, and diminishing to the sides, as 

 in nature. Few pieces of water require to be deeper in the middle than ten feet, which 

 will generally deter cattle from wading across them, and prove unfavorable for the 

 growth of most aquatic plants. Where water is formed by damming up, or throwing a 

 head across a hollow, of which, perhaps, the most notable instance on record is that of 

 Blenheim, the bottom does not require any attention, excepting adjoining the head ; the 

 mass of materials forming which should form an inclined plane under the body of water 

 for the sake of securing the head ; and to prevent the water from penetrating into this 

 mass of materials, its surface should be regularly clayed or puddled over, as well as a 

 part of the firm ground on all sides, and even in the bottom of the excavation. For 

 if this firm ground is of a sandy or gravelly nature, the water may, by entering it, find 

 its way to the mass of new and not yet consolidated earthy matters, and by softening 

 them, speedily ruin the whole mound or head. A safe mode is to leave the head to 

 consolidate for a year or more before filling with water. This was Brown's practice 

 at Blenheim, Harewood Hall, and other places. 



1948. When water is formed on the side of a hill, the lower part of the excavation must 

 be raised and clayed with equal care, as in the case of the head or dam, and for the same 

 reasons. It is almost needless to mention, that claying must never be omitted where 

 the bottom or sides are either newly formed, or not naturally retentive of water. Where 

 clay cannot be had, loamy, or calcareous, and even somewhat sandy earth, by abundant 

 working, becomes retentive of water. This the celebrated engineer Brindley first dis- 

 covered and practised. 



1949. The margin of all water, where nature is imitated, ought, as much as possible, 

 to be formed of stony or gravelly materials, as most likely to give a dry appearance quite 

 to the edge of the water, to admit of walking there, of cattle drinking without poaching 

 and bemiring themselves, and to prevent the growth of such grasses and aquatics as 

 communicate a morassy or marshy appearance ; and finally as being more natural and 

 picturesque than banks of mud. For this purpose, during the excavation, all or a suitable 

 quantity of such gravelly or stony materials as occur, should be reserved for depositing 

 along the margin, for at least one yard beyond the edge of the water, and two yards down 

 the slope of the bed. If suitable materials 

 are not to be had from the excavation, they 

 should be procured ; for without them 

 there can be but little beauty in the mar- 

 gins at least of stagnated water. The 

 margins of rivers may be left in a great 

 degree to nature, watching every proper 

 opportunity after floods or winds, to 

 heighten indications of picturesque effects, 

 not materially inconsistent with local cha- 

 racter and utility. 



1950. In the formation of the head, or 

 dam {fig- 370. d), the points requiring 

 particular attention are the claying, and 

 the forming the sluice or valve for empty- 

 ing the pond. Claying should either be 

 performed over the whole of the inner 

 surface of the head, or by a perpendicular 

 stratum of clay in the middle of the bank. 



