 | 1837 - 1032 páginas
...bottom of the drains, loose gravel or broken stones must be laid in to within a foot of the surface, so that the plough shall not reach them. The water will...absolutely level ; the first thing therefore to be ascertained is the greatest inclination and its direction. For this purpose there is an instrument... | |
 | 1838 - 530 páginas
...bottom of the drains, loose gravel or broken stones must be laid in to within a foot of the surface, so that the plough shall not reach them. The water will...absolutely level ; the first thing therefore to be ascertained is the greatest inclination and its direction. For this purpose there is an instrument... | |
 | Daniel Pereira Gardner - 1846 - 898 páginas
...bottom of the drains, loose gravel or broken stones must be laid to within a foot of the surface, so that the plough shall not reach them. The water will...the advantage of draining more immediately apparent. The average depth is 30 inches. " It is very seldom that a field is absolutely level ; the first thing,... | |
 | Daniel Pereira Gardner - 1846 - 898 páginas
...In no case is the advantage of draining more immediately apparent. The average depth is 30 inches. " It is very seldom that a field is absolutely level ; the first thing, therefore, to be ascertained is the greatest inclination and its direction. For this purpose, there is an instrument... | |
 | Charles Knight - 1851 - 1070 páginas
...within a foot of the surfet*, so hat the plough shall not reach them. The У59 DRAINING. DRAINING. 762 water will gradually sink into these drains, and be...off, and the loose wet soil will become firm and dry. The slope of the field and the fall which can be obtained for the drains, their size and depth below... | |
 | 1853 - 1032 páginas
...bottom of the drains loose gravel or broken stones must be laid to within a foot of the surface, so that the plough shall not reach them. The water will...these drains, and be carried off, and the loose wet toil will become iirni and dry. The slope of the field and the fall which can be obtained for the drains,... | |
 | Daniel Pereira Gardner - 1854 - 890 páginas
...bottom of the drains, loose gravel or broken stones must be laid to within a foot of the surface, so that the plough shall not reach them. The water will...become firm and dry. In no case is the advantage of j draining more immediately apparent The average depth is 30 inches. " It is very seldom that a field... | |
 | William Lewis Rham - 1855 - 522 páginas
...bottom of the drains loose gravel or broken stones must be laid to within a foot of the surface, so that the plough shall not reach them. The water will...absolutely level ; the first thing therefore to be ascertained is the greatest inclination and its direction. For this purpose there is an instrument... | |
 | National cyclopaedia - 1879 - 722 páginas
...bottom of the drains loose gravel or broken stones must be laid to within a foot of the surface, so that the plough shall not reach them. The water will...off, and the loose wet soil will become firm and dry. The slope of the field and the fall which can be obUined for the drains, their sue and depth below... | |
 | 1882 - 406 páginas
...the necessity of filling them with porous substances, through which the surface water can penetrate. It is very seldom that a field is absolutely level ; the first thing, therefore, to be ascertained is, the greatest inclination and its direction. For this purpose there is an instrument... | |
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... filled with water, like a sponge, and no healthy vegetation can take place. In this case numerous drains must be made in the subsoil, and over the draining tiles or bushes which may be laid at the bottom of the drains loose gravel or broken stones... 