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114

Fig. 1.--A dry soil, (from Dr. Madden's lecture)....

-A wet soil *

-A drained soil"
4.--A map of land with swamps, rocks, springs and trees..
5.--Map with 50-foot squares and contour lines.
6.---Levelling instrument......
-

rod...........
8.-Map with contour lines........
9.-Wells' Clinometer........
10.-Stone pit to connect spring with drain...
11.-Stone pit and tile-basin for same object...
12.-Line of saturation between drains.......
13.-Horse-shoe tile............
14.-Sole-tile...................
15.-Double-sole-tile..

....... ...........................
16.-Round tile (or pipe) and collar.........
17.-
18.- Three profiles of drains with different inclinations..........
19.-
20.--Map with drains and contour lines.........
21.-Profile of Drain C.....
22.-Set of tools, (from Drainage des Terres Arables).....
23.-Outlet secured with masonry and grating, (from the same).

118 24.-Silt-basin, built to the surface......

.....121 25.--Finishing spade...........

123 26. SCOOP............

.......123

...
27.-Bracing the sides of drains in soft land..........
28.-Measuring staff. ........

.124 29.-Boning-Rod.........

.....125 30.-Position of workman, and use of scoop, (from Drainage des Terres Arables).........

.......126 31.-Use of Boning-Rods., .,

.......126 32.- Tile-pick......

131 33.-Lateral drain entering at top

.134 34.-Sectional view of joint..

134 35.-Square, brick silt-basin......

135 36.-Silt-basin of vitrified pipe

134 37.-Tile Silt-basin... .......

136 38.- Maul for ramming..............

.. ..... 39.-Board scraper for filling ditches. 40.-Drain with a furrow at each side

141 41.-Foot-pick ..... 42.-Pug-Mill 43.-Plate of dies. 44.-Cheap wooden machine, (from Drainage des Terres Ara

.181 45.-Mandril for carrying tiles from machine, (from the same).

.182 46.-Clay-kiln, (from Journal Royal Agricultural Society)......

184 47.-Dyke and ditch .....

197 48.-oid system of house drainage, from Report of Board of 236 49.-New

Health, (England).

237

124

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CHAPTER XI.

HOUSE DRAINAGE AND TOWN SEWERAGE IN THEIR RELATIONS TO THE

PUBLIC HEALTH.

Sewerage.-The use of pipes. The new outfall sewers in London.-
The use of steam-pumps to secure outlets.-Utilization of sewage
matters in agriculture.—Effects of imperfect house drainage on health.-
Typhoid fever.—The Westminster fever in London.-Epidemic at the

Maplewood Young Ladies Institute, in Pittsfield, Mass.-Lambeth

Square, London.-Back drainage.-Water supply-General Board of

IIсalth, (England).

CHAPTER I.

LAND TO BE DRAINED AND THE REASONS WHY.

Land which requires draining hangs out a sign of its condition, more or less clear, according to its circumstances, but always unmistakable to the practiced eye. Sometimes it is the broad banner of standing water, or dark, wet streaks. in plowed land, when all should be dry and of even color; . sometimes only a fluttering rag of distress in curling corn, or wide-cracking clay, or feeble, spindling, shivering grain, which has survived a precarious winter, on the ice-stilts that have stretched its crown above a wet soil ; sometimes the quarantine flag of rank growth and dank miasmatic fogs.

To recognize these indications is the first office of the drainer; the second, to remove the causes from which they arise.

If a rule could be adopted which would cover the varied circumstances of different soils, it would be somewhat as follows: All lands, of whatever texture or kind, in which the spaces between the particles of soil are filled with water, (whether from rain or from springs) within less than four feet of the surface of the ground, except during and immediately after heavy rains, require draining. . Of course, the particles of the soil cannot be made dry, nor should they be; but, although they should be moist themselves, they should be surrounded with air, not with water. To illustrate this: suppose that water be poured into a barrel filled with chips of wood until it runs over at the top. The spaces between the chips will be filled with

water, and the chips themselves will absorb enough to become thoroughly wet;—this represents the worst condition of a wet soil. If an opening be made at the bottom of the barrel, the water which fills the spaces between the chips will be drawn off, and its place will be taken by air, while the chips themselves will remain wet from the water which they hold by absorption. A drain at the bottom of a wet field draws away the water from the free spaces between its particles, and its place is taken by air, while the particles hold, by attraction, the moisture necessary to a healthy condition of the soil.

There are vast areas of land in this country which do not need draining. The whole range of sands, gravels, light loams and moulds allow water to pass freely through them, and are sufficiently drained by nature, provided, they are as open at the bottom as throughout the mass. A sieve filled with gravel will drain perfectly; a basin filled with the same gravel will not drain at all. More than this, a sieve filled with the stiffest clay, if not “puddled,"* will drain completely, and so will heavy clay soils on porous and well drained subsoils. Money expended in draining such lands as do not require the operation is, of course, wasted; and when there is doubt as to the requirement,

* Puddling is the kneading or rubbing of clay with water, a process by which it becomes almost impervious, retaining this property until thoroughly dried, when its close union is broken by the shrinking of its parts. Puddled clay remains impervious as long as it is saturated with water, and it does not entirely lose this quality until it has been pulverized in a dry state.

A small proportion of clay is sufficient to injure the porousness of the soil by puddling.-A clay subsoil is puddled by being plowed over when too wet, and the injury is of considerable duration. Rain water collected in hollows of stiff land, by the simple movement given it by the wind, so puddles the surface that it holds the water while the adjacent soil is dry and porous.

The term puddling will often be used in this work, and the reader will understand, from this explanation, the meaning with which it is cmployed.

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