substances in suspension in a fluid, even at the water companies’
prices, may be rendered thirty and even more than forty times as cheap
as collection by hand labour and removal by cartage. In the metropolis,
where the persons who water the roads may obtain water gratuitously from
pumps, the water supplied by stand-pipes by some of the water companies
at 1_l._ per 100 tons, is found to be twice as cheap as the mere labour
of pumping the water into the cart. By proper hydraulic arrangements
heavy solid substances may be swept away through the iron pipes.
These means which science gives of cheapening the cost of the conveyance
of refuse from houses, will be available also in extending and
completing the cleansing of the towns, of removing the filth which
oppresses the poorer districts, and rendering the whole of it available,
in the best form, for future use as manure.
The expense of cleansing the streets of the _township_ of Manchester is
5,000_l._ per annum. For this sum the first class of streets, namely,
the most opulent and the large thoroughfares, are cleansed once a-week,
the second class once a-fortnight, and the third class once a-month. But
this provision leaves untouched, or leaves in the condition described in
Dr. Baron Howard’s report, the courts, alleys, and places where the
poorest classes live, and where the cleansing should be daily. There are
abundance of recommendations to the effect, “Let it be ordered that the
streets be properly cleansed;” but in this instance the cost of
cleansing the whole of what is properly the same town, Salford, and the
out-townships, would be 8,000_l._ or 10,000_l._ per annum; and such a
recommendation, under the existing modes of management, is equivalent to
saying, let 20,000_l._ or 30,000_l._ of additional rates be expended,
and 40,000 or 60,000 additional loads of refuse be removed. In other
large towns, the service and the expense is on a similar scale. At the
rate of expense of one large parish, the present cost of cleansing in
the metropolis may be estimated at about 40,000_l._ per annum. This
expense, however, is generally repaid by the sale of the coal-ashes,
which are used in the manufacture of bricks.
Though the refuse of the poorer districts is often taken and sold, the
immediate objection to the extension of the services of the scavenger to
them is the increase of the immediate expense, which it is practically
necessary to consider in detail, although if there were no compensation
by the sale of any coal-ashes or house refuse, and if the occupants were
required to pay for the cleansing at the rate of one of the opulent
parishes in the metropolis, that is at the rate of 4_s._ per house per
annum, which would be less than a penny per tenement for the weekly
street cleansing; or in the poorer districts, where there are mostly two
families to a tenement, a charge of less than one halfpenny per week for
cleansing, would be found to be good economy, as one means of
diminishing the existing heavy charge of sickness, not to speak of the
wear and tear of clothes.
Two-thirds of the usual expense of street cleansing is the expense of
cartage, which, with a proper adaptation of the sewers, is wholly
unnecessary. The exclusive use of hand-labour in street-sweeping is
pronounced by competent judges to be a mere barbarism, and several
machines have been invented which demonstrate that by mechanical power,
moved by horses, the cleansing may be effected in a far shorter time.
Some of these scrape the mud in ridges to the sides, where it remains
until it can be lifted and carted away. But this is objected to as
inconvenient by the shopkeepers, and the scavengers object that it is no
convenience to them, inasmuch as raking it in heaps prevents the
evaporation of the liquid, and increases the cartage; and, moreover,
that the process of sweeping by hand is as quick as the carts can return
for its removal. A machine has been used at Manchester which rapidly and
cleanly sweeps the level surfaces of the streets into a cart; but there
is still the encumberance of the labour, and cost and delay of carting
the refuse to a place of deposit, which may be several miles distant,
and returning to reload. The value of a process of street-cleansing is
proportioned to the rapidity with which it is performed, but at present
it is usually delayed until the sun or the air has done a large portion
of the work by the evaporation of the moisture, commonly however to the
deterioration of the air of the town and the health, and also to the
deterioration of the value of the refuse.
On examining these obstructions to the cleanliness and salubrity of our
towns, it became apparent that the expensive and slow process of the
removal of the surface refuse of the streets by cartage might be
dispensed with, and the whole at once carried away by the mode which is
proved, in the case of the refuse of houses, to be the most rapid,
cheap, and convenient, namely, by sweeping it at once into the sewers,
and discharging it by water.
The sewerage of the metropolis, though it is a frequent subject of boast
to those who have not examined its operations or effects, will be found
to be a vast monument of defective administration, of lavish
expenditure, and extremely defective execution. The general defect of
these works is, that they are so constructed as to accumulate deposits
within them; that the accumulations remain for years, and are at last
only removed at a great expense, and in an offensive manner, by
hand-labour and cartage. The effect is to generate and retain in large
quantities before the houses the gases which it is the object of
cleansing to remove. In the course of the present inquiry instances have
been frequently presented of fevers and deaths occasioned by the escapes
of gas from the sewers into the streets and houses. In the evidence
given before the Committee of the House of Commons, which received
evidence on the subject in 1834, one medical witness stated, that of all
cases of severe typhus that he had seen, eight-tenths were either in
houses of which the drains from the sewers were untrapped, or which,
being trapped, were situated opposite gully-holes; and he mentioned
instances where servants sleeping in the lower rooms of houses were
invariably attacked with fever. It was proposed as a remedy to prevent
the escape of the noxious effluvia by trapping them, but this was
refused on the ground of the danger to the men, who must enter the
sewers to clean them, from the confined gas. In one of the circulars the
reason assigned for allowing the escape of the gas into the streets is
that if it were confined in the sewers it might impede the flow of the
water. It was then proposed to allow the escape of the noxious gases
through chimneys constructed at certain distances. But this was decided
to be an experiment, and the Committee did not feel themselves
authorized to make experiments. Instances were adduced where it had been
found necessary either to trap or to remove gully-holes in the vicinity
of butchers’ shops, to avoid the injurious effects of the effluvium upon
the meat. Similarly mischievous effects of the defective construction
and management of the sewers are commonly displayed in the medical
reports from the provincial towns, and they have been incidentally
noticed in the passages already cited.
It may be mentioned as another instance of the absence of appropriate
knowledge that has governed these structural arrangements, that a large
proportion of the most expensive sewers are constructed with flat
bottoms. In proportion as the water is spread the flow is impeded, and
the deposit of matter it may hold in suspension increased. Mr. Roe, a
civil engineer, who, much to the honour of the Holborn and Finsbury
district of sewers, has been appointed to the care of their sewers, and
is perhaps the only officer having the experience and qualifications of
a civil engineer, states, that as compared with sewers or drains with
bottoms of a semicircular form, those with flat bottoms invariably
occasion a larger amount of deposit; and with the same flow of water,
the difference of construction occasions a difference of more than
one-half in the deposit which is left. By the common and most expensive
form, the drains are apt to be choked up with noxious accumulations; by
being built with flat sides (instead of with curved sides, which give
the strength of an arch) they are apt in clayey and slippery ground to
be forced in. The expense of the improved form is nearly one-fourth less
than those in general use. _Mr. Roe_, whose evidence, which is
corroborated by the evidence of other engineers, is given in the
Appendix, was asked,—
In respect to the levels, how have you found the sewers?—They appear
to have been entirely constructed with reference to the locality, to
drain to the nearest outlet, and not on an extended view for the whole
district, or with any view to sewerage on a large scale. In the
Holborn and Finsbury divisions the Commissioners now adopt a series of
levels suited from the lowest outlets to the surrounding districts.
Have you heard of any alterations made in the surrounding districts on
the same principle?—I have heard of none as adopted generally. The
City have lowered several of their outlets; and the chairman of the
Westminster Commission has had the subject under consideration for
some time.
What are the chief effects of the piecemeal town drainage without
reference to extended levels?—Chiefly that when new lines of houses
are built and require new sewers, either the old sewers must be taken
up and re-constructed at a great expense, to adjust them to a new and
effective sewerage, or the new sewers, if they are adjusted to the old
ones, are deficient in fall, and they have greater deposits.
Does the existing form or system of sewerage answer fully and at the
least expense the chief objects of sewerage in house and street
cleansing, and the removal of noxious substances?—No, it does not,
except where the outlets have been lowered, and the sewers continued
at a proper level; great accumulations of deposit are occasioned in
the sewers, and from their containing the refuse that was at one time
deposited in the cesspools, the deposit is more noxious than formerly;
the gas is more considerable, it escapes more extensively into streets
and into the houses, where the drains are not well trapped. My opinion
is that the general health of the men who work and have been
accustomed to the sewers, has become still worse; they are more pale
and thin, and lower in general health than formerly. The effect of the
noxious gases upon men working in these places is to lower the general
health. Since I have had the superintendence of the sewers, the men
have encountered about half a dozen accidents by explosions of gas.
But is the health of these men who work in the sewers to be taken as a
criterion of the health of persons who are not accustomed to such
places?—I have had no means of forming a comparison, though I am of
opinion that gases which they encounter without any immediate injury
would be very injurious to the health of susceptible persons, or of
any persons not habituated to it.
The first prejudicial effect of the defective system, then, is to
occasion these noxious accumulations; how are they removed?—Formerly,
in the Holborn and Finsbury sewers, and at present, I believe, in all
other sewers, the streets were opened at a great expense and
obstruction (they are so now, I believe, elsewhere); men descend,
scoop up the deposit into pails, which are raised by a windlass to the
surface, and laid there until the carts come; it is laid there until
it is carted away, sometimes for several hours, to the public
annoyance and prejudice. The contract price for removal from the old
sewers without man-holes was 11_s._ per cubic yard of slop removed;
where they have man-holes it was 6_s._ 10_d._ per cubic yard. This
practice also involves injury and expense as respects the pavement; a
street may be well paved when it is broken up for the cleansing of the
sewers, but the portions of pavements so disturbed are never so well
put down again; neither can accidents be effectually guarded against.
By what means may these effects be obviated?—In the Holborn and
Finsbury divisions I suggested a plan of flushing the sewers, and of
carrying off all the refuse by water. This plan has been adopted, and
it is now in operation. The breaking up of the streets is avoided by
the formation of side entrances; cast-iron flushing gates are fixed in
the sewers; the ordinary flow of water in the sewers accumulates at
these gates; the gates are opened, and the force of the water is
sufficient to sweep off the deposit; and the system may be further
extended.
What is the comparative difference in the expense of construction?—The
cost of side entrances and flood-gates, as compared with the cost of
man-holes, is from 6_d._ to 1_s._ less per foot lineal of the length
of new sewers.
What other expense is attendant on this improved practice?—The main
expense is the attendance of a man to shut and open the flood-gates.
The structural expense being lower, is the ultimate expense of
cleansing lower also?—Yes; the expense of cleansing the sewers is
about 50 per cent. less than the prevalent mode. Our expense of
cleansing the sewers was about 1,200_l._ per annum; we save 600_l._ of
that, and expect to save more; but to this must be added the saving to
the public of the cleansing of the private drains, formerly choked by
the accumulations in the sewers. This saving, on a moderate
calculation, is found to be upwards of 300_l._ per annum. There is
also the diminution of the escapes of gas from the old and continued
accumulations.
During what intervals are deposits allowed to remain on the old
mode?—The average is in one set of sewers about five years, and in
another about ten years.
During which time the public are subjected to all the escapes of gas
from the decomposing accumulation?—Exactly so. It could not, however
go on so long but for heavy falls of rain or snow, which occasion
partial clearances.
What is the effect of these accumulations upon the private
drainage?—That the drains to the private houses are stopped: the first
intimation of the foul state of the main sewer arises from complaints
of individuals whose drains are affected; the accumulations in the
private drains also occasions an expense to the individuals and much
annoyance. By flushing the sewers this expense might be, and in
Holborn and Finsbury division it is, avoided.
Are there any other defects you have, as an engineer, noticed in the
prevalent mode of constructing the sewers?—Yes, the prevalent practice
is to join sewers at angles, frequently at right angles; this
occasions eddies and deposits of sediment that would otherwise pass
off with the water; it injures the capacity of the main sewers by
obstructing the current of water along them: I ascertained by
experiment that the time occupied in the passage of an equal quantity
of water, along similar lengths of sewer with equal falls, was—
Seconds.
Along a straight line 90
With a true curve 100
With a turn at right angles 140
The Commissioners of the Holborn and Finsbury divisions agreed to
require that the curves in sewers, passing from one street to another,
shall be formed with a radius of not less than 20 feet; it is also
required that the inclination or fall shall be increased at the
junction, in order to preserve an equal capacity for the passage of
water, and of effect in sweeping away the deposit.
When by heavy falls of snow or otherwise the refuse of the streets is
carried into such sewers, is there any difficulty in sweeping it
away?—None whatsoever.
In what number of years would the saving in cleansing sewers by
flushing repay the expense of applying the apparatus to the existing
sewers in the Holborn and Finsbury divisions?—In seven years.
Have you any doubt of the practicability of carrying all the surface
cleansing of the streets into the sewers, and removing it by
conveyance in water, instead of by hand labour and cartage?—I
entertain no doubt whatever that it might be done, where there is a
good sewer and proper gully-holes and shoots; with a good supply of
water these would carry away rapidly all the surface refuse; the
experience of the sewerage in the Holborn and Finsbury divisions prove
it.
How does it prove it?—At every opportunity the street-sweepers sweep
all they can into the gully-holes, and it is swept away without
inconvenience.
One practical witness states that the expense of the cartage alone of
the refuse from a Macadamised street of half a mile, in the winter
time in the metropolis, is 5_l._ weekly. What would be the comparative
expense of carrying it away by the sewers?—It would save the whole
expense of the cartage; it would be less than the present expense of
sweeping and filling into the carts, and if there were a sufficient
supply of water on the surface, the work might be conducted with great
rapidity.
You are aware that one inconvenience of the existing mode of street
cleansing, independently of the great expense, is the length of time
during which the wet refuse remains to the public annoyance on the
surface, until removed by the slow process of sweeping and
cartage?—Yes; and the men would appear to delay for the purpose of the
dirt being removed, by being washed by rain into the sewers.
Do you conceive that all the business of street cleansing and house
draining might be consolidated advantageously to the public?—Yes,
clearly so, and with great economy.
In the evidence of Mr. Oldfield, an experienced builder in the wealthy
districts of the metropolis, will be found exemplifications of the
mischiefs resulting from the defective modes of opening sub-drains or
communications, even from houses of the first class, into the main
drains.[7] The state of sewerage and drainage in the larger towns, as
described in the medical reports, in its effects of frequent disease and
death,—is much worse in the provincial towns. But every step in
improvement is an advance in reduction of existing burdens; drainage,
_per se_, will be found to be a reduction of an existing charge for the
expenses of sickness and mortality; _science_, applied to the
improvement of drainage, not only gives it efficiency, but reduces
greatly the expense.
The streets in the larger towns commonly display, from the want of
science in their construction, similar waste, and equally admit of an
improved and scientific arrangement, which will conduce to economy and
to improved public health.
The bad condition of the streets in many of the towns is very generally
ascribable to pavement being commonly regarded as requisite solely for
cart or carriage conveyance, and not as a means of cleanliness. The
pavement has therefore been usually confined to the chief streets in
which the carriage traffic is considerable. Some of the principal
streets even in the metropolis almost justify the description of being
“streams of mud and filth in winter,” and “seas of dust” in summer. But
attention has of late been directed to the cleansing of the road as a
means of removing damp and dirt or dust, which are each found to be
injurious. So far as various experiments have yet proceeded in the
metropolis, they are stated to be highly favourable to the use of wood
as a substance for paving the streets, though perhaps in forms different
from those at present in use, with improvements which further experience
will suggest. Wood, when pinned together and laid on a firm substratum,
appears to be less retentive of wet than most forms of stone pavement,
and to possess very considerable advantages over the Macadamised roads
for crowded thoroughfares. If it be brought into general use it will
have an advantage in removing the granite dust, which medical
authorities believe to be much more prejudicial to health, in exciting
or aggravating lung diseases, than the public have been aware of. Where
there is much dust in the working of close quarries, the effects of it
are almost as destructive to the lungs of the operatives as the
knife-grinding to the operatives of Sheffield who do not guard against
the steel-dust. “It is scarcely conceivable,” Dr. Arnott states, “that
the immense quantities of granite-dust pounded by one or two hundred
thousand pairs of wheels working on Macadamised streets, should not
greatly injure the public health. In houses bordering such streets or
roads, it is found that, notwithstanding the practice of watering, the
furniture is often covered with dust even more than once in the day, so
that writing on it with the finger becomes legible, and the lungs and
air-tubes of the inhabitants, with a moist lining to detain the dust,
are constantly pumping the same atmosphere. The passengers by a
stage-coach in dry weather, when the wind is moving with them so as to
keep them enveloped in the cloud of dust raised by the horses’ feet and
the wheels of the coach, have their clothes soon saturated to whiteness
with the dust, and their lungs of course are charged in a corresponding
degree. A gentleman who rode only 20 miles in this way, had afterwards
to cough and expectorate for 10 days to clear his chest again.” The
imperfection of road cleansing in paved streets at the same time
deteriorates the salubrity of the towns, the value of the refuse for
production, and the streets themselves. The farmers find that the refuse
of the streets, of which horse-dung and other excrementitious substances
form so important a part, is valuable in proportion as it is “fresh.” On
a proposition to sweep the streets of a town district oftener, it was
stated by some farmers that they would, in that case, give more for the
refuse. It is with this description of refuse, as stated with respect to
the night-soil, in proportion as it is allowed to remain in the streets
to dry, it loses the gas which gives it value; and the gas which is lost
frequently gives to streets the offensive smell perceptible to strangers
who have not been familiarised to it, and makes a deleterious addition
to the compounds by which the health of the town population is injured.
The complete and rapid cleansing of the roads has also its effects on
the draught. It is proved experimentally that, “calling the draught on a
broken-stone road 5, that on the same road covered with dust is 8, and
that on the same road wet and muddy is 10.”[8] A road should be cleansed
“from time to time, so as never to have half an inch of mud upon it.
This is particularly necessary to be attended to where the materials are
weak, for if the surface is not kept clean, so as to admit of its
becoming dry in the intervals between showers of rain, it will be
rapidly worn away.” With the even surface obtainable from the use of
wood as a pavement, it is stated that the streets which are now kept wet
and dirty whilst the process of cleansing is slowly carried on by the
hand, may be rapidly and cheaply swept by sweeping-machines drawn by
horses. With the advantage of such a system of sewerage as that
described by Mr. Roe, the surface refuse, which continues exposed during
a whole week, may be removed every morning before the hours of traffic
from all the principal thoroughfares. In the main streets of the towns
of considerable traffic, a smooth and firm surface for the carriage-way
would ensure the advantages of a railroad, in addition to those to the
public health from cleanliness. The experience on several portions of
smooth road shows that single horses with lighter and less expensive
vehicles would suffice where two horses are now required on the common
roads; where strong stone pavements are required to resist the shock of
heavy vehicles, and heavy vehicles propelled with double power to resist
the battering of strong pavements, and the grinding and wear and tear of
heavy and dirty roads.
_Captain Vetch_, the engineer, who is extensively acquainted with the
structural economy of towns, observes in a communication on the subject,
that—