_LOCATION OF A HOUSE--SOIL AND SURROUNDINGS_
In attempting to develop a system of rural hygiene, by means of which
the full value of the advantages of pure air and sunlight, of healthful
exercise and sound sleep, may be realized, the first step should be a
proper location of the house. For, while it is possible to have good
health in houses not advantageously located, and while the influence of
unsanitary surroundings is not as great as was formerly supposed, yet
there can be no question but that some influences, whether they be great
or small, must result directly from the situation of a dwelling. For
example, it has been noticed that a house whose cellar was damp was an
unhealthy house to live in, and early text-books on hygiene quote
statistics at length to prove this fact.
The early theories connecting ill-health with conditions in and around
the house have been handed down, and to-day some are accepted as true,
although by the modern science of bacteriology most of the early notions
have been upset. For example, it was considered dangerous to breathe
night air in the vicinity of swamps, and in one of the Rollo Books, so
much read by the children of the last generation, Uncle George requires
Rollo, on a night journey through the Italian marshes, to stay inside
the coach with the windows closed in order not to breathe the night air
and so contract malarial fever. We know to-day that malarial fever comes
only from mosquitoes, that night air has nothing to do with disease, and
we hear the general advice of doctors that, except where it means the
admission of mosquitoes, we should always sleep with our windows open in
order to breathe as much night air as possible, because the night air is
purer than any other air. These early traditions have not only concerned
themselves with damp cellars and night air, but they have insisted that
even the vicinity of a swamp or pond might lead to disease, and the
State Department of Health of New York is in constant receipt of
complaints because of alleged danger to health on account of some pond
or swamp in the vicinity of houses.
Again, one tradition says that a house should not be located in the
midst of a dense growth of trees, because the shade of the trees,
however welcome in summer, will generate and maintain a condition of
dampness in the house and, therefore, be injurious to the health of the
inmates.
Another tradition is that a house ought not to be located in a valley,
but that a hilltop, or at least a sidehill elevation, is preferable, the
possible dampness of the valley being alleged again as the reason.
To-day, so far as is known, there is no direct evidence of dampness
being primarily responsible for any disease, although, heretofore, such
diseases as typhoid fever, yellow fever, bilious fever, malarial fever,
cholera, and dysentery have all been attributed to miasms springing
from damp soil. To-day we are assured by experts that none of these
diseases are induced by dampness alone. One could spend his days
immersed in water up to his chin and never contract any sickness of the
types mentioned merely through that act. Later on, we shall show how the
presence of swamps in the vicinity of a house is objectionable because
of their providing breeding places for insects, but the dampness itself
never has and never will cause disease. As a concrete example, it may be
noted that the country of Holland, in large part lying below the level
of the sea, with drainage canals and ditches everywhere in evidence, is,
in spite of such manifest possibilities of dampness, one of the most
healthy countries in the world, as already pointed out in Chapter I.
This fact not only emphasizes the small effect of surface waters and
damp soils in promoting disease, but also magnifies the value of
cleanliness for which the Dutch people are so famous.
_Damp soils._
Why is it, then, that damp soils and damp cellars are objected to?
Chiefly, because of the inconvenience and discomfort they occasion. A
damp cellar means conditions favorable to the development of mildew and
rot; prevents vegetables from keeping a normal length of time; accounts
for moldy, decaying odors throughout the house, and is generally
disagreeable. One is tempted to say that such a condition is also
unhealthy, and it is quite possible that a person living over a damp
cellar which contains accumulations of decaying vegetables, and
breathing air loaded with organic compounds, may gradually lose his
normal vitality, and become thereby more readily susceptible to specific
diseases, but the diseases themselves will not come from the dampness
alone.
[Illustration: FIG. 2--Bad conditions about a dwelling.]
The discomfort and inconvenience, however, are quite sufficient reasons
to make it eminently desirable to have the house and the cellar dry.
With this in mind, the selection of the house site should be carefully
made. Instinctively, and with reason, the immediate neighborhood of low,
swampy, marshy ground, of stagnant ponds, or of sluggish streams should
be avoided. It should not be necessary to warn prospective builders that
low land, subject to inundation, even though this may happen only
occasionally, is not a wise choice of a building site. Figure 2 shows an
inundation in a small village of New York State in 1889. Floods are
expected each spring and counted on as a part of the year's experience.
The resulting exposure and the inevitable effluvia following the
receding waters are both objectionable factors in hygienic living.
Similarly, the vicinity of a stream carrying organic matter, such as
sewage from a town above, should undoubtedly be avoided on account of
possible odors in summer. Not long ago, the writer was told by the owner
of a productive farm, situated below a small city in New York State,
that in the summer time the windows of his house had all to be kept
tightly shut at night, because of the effluvia from a stream a thousand
feet distant, which carried the sewage from the city above.
_Location of house._
A deep and narrow valley should be avoided, not so much because of the
possible dampness in the valley, but because of the noticeably lessened
amount of sunlight which such a location involves. For such a house, the
morning sun comes up much later, and the afternoon sun disappears much
earlier, and, since sunlight is the best foe to disease, the more
sunlight enters a house, the healthier are those who live in it. On the
other hand, the top of a hill exposes a house to strong and cold winds,
not desirable on any account, and involving a large expense for heating
in winter. Sloping ground, therefore, facing the south if possible, or
better, some knoll which rises above the general surface of a southern
slope, affords an ideal location. If the slope is toward the south,
north winds are kept off, and every ray of the life-giving winter's sun
is captured. If the house itself faces due south, the windows on the
north have no sunlight. If, on the other hand, the house faces southeast
or southwest, then all sides of the house will receive direct sunlight
at some time of the day.
_Objections to trees._
The vicinity of trees is not to be regarded as altogether evil, since
they provide both shade in summer and a screen against winds in the
winter. No disease comes from dampness because of their presence, and
the worst thing which may be charged against a thick growth is that it
keeps out the sun. Practically two points may, however, be urged against
trees growing too close to a house. If near enough for leaves to drop on
the roof, rain troughs and leaders become stopped up and cause trouble.
A thick growth directly over a shingle roof allows organic matter to
accumulate on the shingles, so that vegetation develops and the roof
decays more rapidly than if exposed to sun and wind. Again, and it is no
trivial matter, a house whose roof is easily accessible from trees is
apt to become infested with squirrels, who get into the attic, run
through the walls, and become a great nuisance. For these reasons, then,
trees should be far enough away from the house to allow the sun to enter
the windows freely and to keep away from the roof objectionable animals,
large and small.
_Space between houses._
It is a law or custom as ancient as the Romans that requires a
proprietor to build his house so that the eaves should not overhang on
the land of his neighbor. Our grandfathers, with the same idea, used to
say that a man should be able to drive his team around his house on his
own land. In our day it is highly desirable that a house should be built
so as to leave as much land under control between the buildings and the
lot line as possible. This, of course, does not apply to houses built on
a farm of a hundred acres or more, but rather to the house in a small
village where a few hundred people live closely together, under rural
conditions. In such a village the water-supply usually comes from wells,
and the wastes of the household are discharged into privies and
cesspools. There is no law, unfortunately, which restricts the location
of either of these two essential structures, and it is quite possible
for a well, built within a few feet of a property line, to be ruined in
quality by a cesspool, built later, on the other side of the line. It
seems very unjust that, after the trouble and expense of building a
well, a neighbor may render it worthless by the location of his
cesspool, and yet, unless one can prove a direct underground connection
between well and cesspool, no law is applicable to prevent the
construction of the latter.
Besides such a menace to health, there are other objections to the
immediate vicinity of neighbors which can be avoided by a judicious
interposition of space. For example, the writer listened through a long
evening, recently, to a hearing before a City Commissioner of Health,
where one householder and a crowd of witnesses complained of the noise
made by a kicking horse in an adjacent stable. The one witness who was
not disturbed by the noise, and who lived in the vicinity, was
unexpectedly found to be deaf.
It is wisdom also to have a reasonable space between a house and the
highway, chiefly because the dust of the road is thereby kept from the
house. There are people who find much enjoyment in watching passers-by
on the road, and with them front windows would be as close to the road
as possible, but it is wiser to have a front yard of at least fifty feet
depth when possible.
Finally, the location on a sidehill, even when otherwise advantageous,
is to be regarded with suspicion if the subsoil strata are horizontal
and neighbors up the slope have cesspools in use. The writer knows of
several cesspools, built in rock, which, so far as their owners were
concerned, have worked successfully for many years, but the water
leeching away through the rock was finally discovered to be the cause of
continual dampness in neighboring cellars, on lower ground, to the
manifest discomfort of those occupying the houses.
_Composition of soils._
Having thus discussed the location of the house with reference to its
surroundings, let us now more carefully examine the character of the
soil or earth foundation on which the house shall be built. All soil is
made up of varying proportions of mineral and vegetable matter in the
interstices of which there are usually to be found more or less air,
water, and watery vapor. The mineral substances of soil include almost
all of the known minerals, although many of them are found in
exceedingly small quantities. The most common and the most important
mineral elements of the soil of New York State are carbon, silicon,
aluminum, and calcium, which combine in various ways to make either
sand, sandstone, clay, shale, limestone, or other rock. The particular
form which these mineral elements assume is of interest in choosing a
location for a house, for two reasons:--
In the first place, it has been asserted that the mineral constituents
of a soil directly affect the health of persons living on that material.
For instance, the earlier writers on hygiene gravely pointed out that
very hard granite rocks, when weathered and disintegrated, became
permeated by a fungus and caused malaria. We are, however, now so sure
of the cause of malaria that we only laugh at a theory upheld by
scientists of only twenty years ago.
Some constitutional diseases, including goiter and cancer, have been
supposed to flourish in localities where an excess of calcium exists in
the soil, and it is true that these diseases do have an unusual
prevalence in certain limited districts; but no modern scientist
ventures to say whether the boundaries of those districts are determined
by the character of the soil constituents or by some other predisposing
factor. The truth is that, in matters not absolutely determined by
science, many theories usually have to be evolved and proved worthless
before the real cause is found.
In the matter of appendicitis, for instance, it was formerly asserted
that the seed of grapes was responsible for the local inflammation, and
that one could never have appendicitis if such seeds were not swallowed.
This theory is to-day almost forgotten, and one eminent surgeon has
asserted that the prevalence of this disease in a district depends on
the calcium in the soil, since it is to that mineral that hard water is
due, although this has not been substantiated. No information is to-day
available by which the fitness of a soil for securing sanitary
conditions of building can be determined.
_Cancer and soil conditions._
In the case of cancer, however, while no final conclusions can be drawn,
there is some definite indication that the soil conditions have
connection with the occurrence and continued appearance of cancer. It is
known that this dread disease is abnormally prevalent in certain
districts of the world where topography and climate are fairly alike.
For example, the entire region between the Danube and the Alps from
Vienna westward and between the Jura and Alps to Geneva furnishes the
highest mortality from cancer in all Europe. The subsoil is clay with a
thin covering of surface soil, the hillsides draining on to level
valleys with meandering watercourses that frequently inundate and
supersaturate the already moist soil.
This condition seems to prevail wherever cancer is abnormally prevalent.
In England, in northwestern France, and in Spain the topography
described in every case accompanies a high death-rate from cancer. It is
of great interest to find that in New York State the two districts that
are conspicuously affected by this disease have the same topography. The
Unadilla Valley and some parts of the Allegheny Valley are noted for
their cancer houses, and in both localities we find the same kinds of
hillsides and water-soaked valleys as in Germany and France. It has also
been noted that the older geological formations are free from the
disease and that an occasional inundation does not seem to be a factor.
Altogether there seems to be some ground for assuming a connection
between cancer and soil conditions, at any rate until scientists have
determined the real cause of the disease in those localities where it is
now so markedly prevalent.
_Topography._
The soil, however, with its mineral characteristics, does indirectly
affect the health of the householder because different kinds of rock
form themselves naturally into different surface formations, some
healthy and some unhealthy. For example, localities where granite rock
abounds and comes near the surface are usually healthy because the
surface slope is great enough to carry off all drainage water rapidly.
The air therefore is dry and not influenced by the immediate vicinity of
swamps. The drinking water is soft, and malarial breeding places are
usually absent.
Limestone rock, on the other hand, is commonly laid down in horizontal
strata, and while a succession of strata may frequently give rapid
slopes, marshes are very common, existing even on the tops of the hills.
The drinking water is always to be suspected as to quality because, in
the first place, it is hard from absorption of lime, and in the next
place, cavities and seams in the rock allow polluting material to travel
for long distances.
Sandstone, being porous, may be considered a healthy foundation, and
sands and gravels of all sorts are usually free from marshy land.
Gravel has always been assumed to be the healthiest soil on which a
house could be built, provided the ground water reaches its highest
stage three or four feet below the cellar bottom.
Sand is equally desirable except in the cases where vegetable matter has
been mixed with the sand, rendering decay imminent. Water drawn from
such sands in the form of springs will contain large quantities of
nitrates which may lead to excessive development of vegetable life and
may have on the human system the same laxative effect as comes from
drinking swamp water.
Clays and heavy alluvial soils are not usually considered desirable
soils on which to build. Water does not run from such soils; they hold
moisture, and hence are always damp, and marshes are very apt to exist
in the vicinity.
_Effects of cultivation._
It was formerly thought that extensive cultivation was objectionable
from the standpoint of health, that manured fields in the vicinity of a
house were undesirable, and that the turning up of a well-manured field
with a plow in the spring was a very likely source of fever. It is a
very common belief to-day that when water pipes are to be laid in city
streets, thereby disturbing the soil and bringing fresh earth to the
surface, typhoid or other fevers may be expected. There is, however, no
ground for this belief, and the fact that laborers and their families
live healthily in the midst of the thousands of acres of
sewage-irrigated fields near Berlin, where the heavily manured fields
are constantly being plowed, is a sure proof of this. The earlier
text-books on hygiene all assert, however, the contrary; Parkes, for
instance, says that irrigated lands, especially rice fields, which give
a great surface for evaporation and also exhale organic matter into the
air, are hurtful, and in northern Italy the rice grounds are required to
be three quarters of a mile from the small towns to protect the village
inhabitants against fevers. There is no ground, however, for such a
requirement.
No evidence can be found that men who work in sewers and who breathe
sewer air all the time are especially unhealthy. Statistics show that
the laborers on the sewage fields of Paris and Berlin are actually
healthier than the average person living within those cities.
No reason can be assigned, based on our present knowledge of
bacteriology, why upturned earth or manured fields should be unhealthy
except as the breeding of insects may be encouraged thereby. The two
essentials, however, which should be considered are: first, the
topography or the formation of the soil in order that the surface water
may run off freely, and second, the character of the soil so that ground
water may not remain too near the surface. Whether the soil is rock or
gravel makes very little difference.
_Made ground._
One kind of soil, however, is distinctly objectionable, although,
fortunately, in the country such a soil is unusual: That is, a soil made
up of refuse, whether it be garbage, street sweepings from a near-by
city, or factory refuse.
The writer has in mind one enterprising landowner and farmer who offered
a near-by city the free privilege of dumping the city garbage on his
land. This was done for several years, and the low-lying districts of
his farm were all filled to a more advantageous level. This garbage was
then covered with about a foot of dirt and the land sold in building
lots to enterprising laborers determined to own their own homes.
According to the old theories of hygiene, the occupants of such houses
should have died like rats, but no particular excess of sickness in the
one hundred houses so located could be observed. One must, however,
believe, as we shall see later, that the repeated breathing of air drawn
from such polluted soil must be unhealthy, even though the mortality
records fail to show it.
It is interesting in this connection to note that the organic matter in
soil gradually disappears, just as a body buried in a grave will finally
decompose. Experiments show that such organic matter as wheat straw or
cloth in small pieces rots and decays in about three years. But this
depends very largely on an excess of air. If the soil is open and the
organic matter loose, oxidation takes place rapidly; but if a large pile
of organic matter is buried in clay soil, it will take decades for it to
disappear. The vegetable matter in soil is usually produced by the decay
of plants which have either grown on the soil or have been washed down
into its voids. A great deal was formerly written on the relation
between this organic matter and the prevalence of malaria, and some
earlier writers believed that the amount of malaria in a district was
dependent upon the amount of vegetable debris in the soil. Since we have
learned that malaria is carried by mosquitoes, we are less interested in
the amount of organic matter in the soil. Its mere presence is not
likely to be injurious.
_Water in the soil._
Only the hardest rocks are entirely solid, the others containing a
certain percentage of voids or interstices. These voids are filled with
air or water, as the case may be, and we may stop for a moment to
inquire the effect of the presence of this air and water. In loose sands
the amount of voids is 40 to 50 per cent of the total volume, in
sandstone about 20 per cent, and in other rock reduced amounts. The
volume of air, therefore, in the soil under a cellar to a depth of four
or five feet, amounts to a good many cubic feet and would not be worth
inquiring into except for the fact that it is continually in a state of
motion. When the ground water, perhaps normally five feet below the
cellar bottom, rises in the spring, this ground air is forced out, and
in a cellar without a concrete foundation it rises into the cellar and
penetrates into the house.
A house artificially warmed by stoves is continually discharging heated
air from the tops of the rooms and colder air is being brought in from
below to take its place. This air comes from the ground below, and in
open soil may come from a great depth. A case has been noted where gas
escaping from a main in a city street twenty feet from a cellar wall
was, by the suction due to heat, drawn into the cellar and thence into
the rooms of the house. It is possible that air from cesspools and
broken drains in the vicinity of a house may, in this same way,
contribute to the atmosphere breathed within the walls of the house.
Gravelly and sandy soils, therefore, in order to maintain the
superiority which they furnish for building construction, should not be
polluted, since any pollution in the vicinity influences the quality of
air which may get into the house. The method of preventing such ingress
is plainly to water-proof the outside walls of the cellar and provide an
air-tight floor over the cellar bottom. Methods of doing this will be
discussed in the next chapter.
_Moisture in soils._
The presence of water in the soil has usually been considered to be
unhealthy because of the impression that it led to certain fevers. The
writer has heard, for instance, of an attack of malaria being caused by
a short visit to a damp vegetable cellar; and it is one of the triumphs
of the century that the malarial parasite has been discovered, and the
old theory of the dangers of moisture been done away with. A damp cellar
has always been considered to be undesirable, but just why nobody
knows. A damp cellar causes molds to form rapidly, thus destroying
vegetables and other material which might naturally be stored there, but
that the presence of moisture in a cellar in itself produces any organic
emanation leading to disease is not true, although dampness is essential
to the growth of certain organisms.
In the latter part of the nineteenth century, Dr. Bowditch, of Boston,
showed that consumption developed most where the surrounding soil was
moist, and generally it is the impression that dry air is the only
proper air for a consumptive person to breathe. This theory, however, is
being rapidly exploded, and patients now remain outdoors in any weather,
and no kind of air is objected to by physicians, provided it is outdoor
air. Some little time ago the writer was called by a Board of Health to
investigate a certain swamp which had some odor, was considered a blot
on the landscape in an unusually picturesque village, and was said to be
responsible for a long list of contagious diseases. A house-to-house
inquiry in the vicinity showed that among some dozen families, only one
illness in the last few years could be remembered, and that was an old
lady who had been on the verge of the grave for forty years.
It is curious to note the many examples which are cited by the earlier
sanitarians to prove the dangerous effect of damp soil. For example,
Pettenkofer, a very prominent German hygienist, says that in two royal
stables near Munich, with the same arrangements as to stalls, feed, and
attendance, and the same class of horses, fever affected the horses very
unequally. In one stable, fever was continually prevalent; in the
other, no fever was found. Horses sent from the unhealthful to the
healthful stables did not communicate the disease. The difference
between the two places, says Pettenkofer, was that in the healthful
stables the ground water was five to six feet below the surface, while
in the unhealthful ones it was only two and a half feet from the
surface. A system of drainage by which the ground water was brought to
the same level under both stables made them equally healthful. The
writer cannot help but feel that some other factor was involved, and
while he has no doubt that excessive dampness in stables or cellars is
undesirable, he does not believe that such dampness can be directly the
cause of fevers of any sort.
It is not desirable, however, to live over a wet cellar nor to maintain
a house in a constant condition of dampness, partly on account of its
bad effect on the house and partly because such dampness may, by
reducing the vitality of the household, become a predisposing factor in
disease.
_Drainage._
From whatever source dampness may come, it can be guarded against by
giving to the surface of the ground in the vicinity of the house, on all
sides, sufficient slope away from the walls so that there will be no
tendency for water to accumulate against the cellar walls. On the top of
a hill this is very easy to do, and the natural surface grade takes care
of the surface water without difficulty. On a sidehill or in a valley
artificial grading has to be resorted to, except on one side.
[Illustration: FIG. 3.--A grading that turns water away from the house.]
Too much emphasis cannot be laid on the necessity for grading the ground
surface away from the house. In some cases it may be sufficient to dig a
broad shallow trench protected from wash by sods (Fig. 3). In other
cases it may be desirable to pave the ditch with cobble stones or to
build a cement gutter. In constructing such a surface drain, proper
allowance must be made for the accumulation of snow and the resulting
amount of water in the spring, so that the distance in which the ground
slopes away from the house ought to be, if possible, at least ten feet,
so that there can be no standing water to penetrate the house walls. The
slope necessary to carry surface water away need not be great. A fall of
one foot in one hundred will be ample, even on grassy areas, and if the
surface is that of a macadam road or the gutters of a drive, this grade
may be cut in two. A slope of more than one foot in one hundred is
permissible up to a maximum of seven or eight feet per hundred, more
than this being aesthetically objectionable and tending to make the house
appear too high. Whenever gutters are built in driveways or ditches to
intercept water coming down the slopes, a suitable outlet must be
provided to carry the water thus collected either into underground
pipes, by which the water is led to some stream or gulley, or directly
into some well-marked surface depression.
_Ground water._
The soil always contains water at a greater or less depth, and the
elevation of this "ground water," as it is called, varies throughout the
year partly with the rainfall and partly with the elevation of the water
level in the near-by streams.
It is not at all unusual for this ground water to rise and fall six feet
or more within the year, high levels coming usually in the spring and
fall, and low levels in the late summer and winter. It is easily
possible, then, that a house cellar may seem dry at the time of
construction in summer and may develop water to a foot or more in depth
after occupancy. The presence of such an amount of water in a cellar,
whether injurious to health or not, is objectionable, and a subsoil
trench should be provided in order to limit the height to which ground
water may rise.
If a system of drainpipes is led around a house extending outward to
include the surrounding yard, then the ground water will always be
maintained at the level of those pipes, provided the system has a free
outlet. Indeed, the question of an outlet for a drainage system is a
most important factor, and no system of underdrains can be effective
unless a stream or gulley or depression of some kind is available into
which the drains may discharge. It is for this reason, quite as much as
for any other, that the location of a house on a perfectly level bottom
land is objectionable, since the ground there may be normally full of
water with no existing depression into which it may be drained.
In the next chapter the proper method of laying drains close to the
cellar wall, for the purpose of taking away the dampness from those
walls, is described, but another system of drains is desirable, covering
more area and more thoroughly drying the ground, provided the ground
water needs attention at all. These drains should be laid like all
agricultural drainage; and while substitution of broken stone, bundles
of twigs, wooden boxes, or flat stone may be made, the only proper
material to be used is burnt clay in the form of tile. These tiles are
made in a variety of patterns, but the most common in use to-day is one
which is octagonal outside and circular inside. They are about one foot
in length and may be had from two to six inches inside diameter. The
ordinary size for laterals is four-inch diameter, while the mains into
which these laterals discharge are generally of six-inch diameter. These
tiles are laid in trenches about fifteen feet apart, although in porous
soil, such as coarse sand or gravel, this distance may be increased to
twenty feet. If the tiles are laid more than four feet below the
surface, this distance may be increased, and if the tiles are five feet
deep, the distance apart of the several lines may be fifty feet.
The grade of the line must be carefully taken care of, and while it is
possible to lay a line of tile with a carpenter's level and a
sixteen-foot straightedge, it is much safer to have an engineer's or
architect's level and set grade stakes, as in regular sewer work. A fall
of one fourth of an inch to the foot is a proper grade, although a
greater slope is not objectionable. It is sometimes desirable in soft
ground to lay down a board six inches wide in the bottom of a trench on
which to rest the tile, but, unless the ground is very soft, this is not
necessary. Care must be taken, however, if the board is not used, to
have the bottom of the trench very carefully smoothed so that a
perfectly even grade in the tile is maintained. There are three ways of
laying out a line of trench as shown in the following sketches (Fig. 4).
It is usually sufficient to run parallel lines of tile from fifteen to
fifty feet apart over the area which it is desired to drain, and let the
ends of these lines enter a cross line which shall carry off the water
led into it. This cross line should be six inches in diameter as a
general rule, unless there is more than a mile of small drains, in which
case the size of the cross pipe ought to be increased to eight inches.
This cross line then becomes the main outlet, and great care must be
taken to see that it has a perfectly free delivery at all times of the
year. In cities and sometimes in small villages it is possible to
discharge this outlet pipe into a regular public sewer, provided the
sewer is deep enough, and provided the municipal ordinances allow such a
connection. Otherwise, the outfall must be carried to a natural
depression.
[Illustration: FIG. 4.--Modes of laying out drains.]
In level ground, the problem of finding a suitable outlet is a serious
one, and in many cases impossible of solution, so that the householder,
being unable to find an outlet, must put up with the ground water and be
as patient as possible during its prevalence. It does not do to trust
one's eye to find a practicable outlet, since even a trained eye is
easily deceived. An engineer with a level can tell in a few moments
where a proper point of discharge may be found, and it is absurd to
begrudge the small amount which it will cost, in view of the large
expense involved in digging a long trench to no purpose.
Some years ago the writer was able to note the conditions in a house
where the cellar excavation went three feet into limestone rock. The
strata were perfectly level and the cellar floor of natural rock was
apparently all that could be desired, smooth and flat, without involving
any expense for concrete. One wall came where a vertical seam in the
rock existed, and since this natural rock face was smooth and vertical
and just where the cellar wall should go, it seemed unnecessary to dig
it out and lay up masonry in its place. So it was left and the house
built. When the spring rains came, however, the cellar was turned into a
pond, water dripping everywhere from the vertical rock face, and coming
up through the cellar bottom like springs. It cost a great deal more
then to make the changes and improvements necessary in order to secure a
dry cellar than it would have done at the outset. This serves as an
illustration of the need of taking every precaution at the beginning to
insure a dry and well-drained soil around and below the cellar walls.