The Sun.
London, England, 1862-02-26 00:00:00

SEWER VENTILATION:

An experiment, costing about £l,OOO, has re,
cently been made by Dr. Letheby, the medical
officer of health, and Mr. William Haywood, the
engineer to the Commissioners of Sewers, with the
view of testing the effects of the application of
charcoal to the ventilating openings of the sewers
in the City of London. It proceeded on the theory,
maintained by eminent French and English cby-
mists, that charcoal has the power of absorbing
and oxydizing the miasma of organic decomposition
when they are passed over it, with atmospheric air.
A district was selected for the experiment in the
eastern part of the city, comprising a space of about
59 acres, with about 1,700 houses, and 14,000 inha-
bitants, bounded by Bishopsgate-street on the west,
from Cornhill to Widegate-street ; by Middlesex-
street and Somerset-street on the east. to the city
boundary; and by the Minories and Leaden hall-
street to Corn hill on the South; the whole of these
main thoroughfares being included in the arca.
This district was selected because the sewers there
have but a slight fall, and the currents in them
are sluggish; because the area is densely populated,
and has more than an average proportion of resi-
dent poor; and because the thoroughfares are mostly
narrow, and are therefore disagreeably affected by
the sewer gases which issue from the ventilators.
The total length of sewers in the district is 25,587
feet, of which 2,018 feet are pipes, and the remainder
are constructed of brick, varying from 3ft. high by
2ft. wide to sft. high by 3ft. wide, internal dimen-
sions. Upon this length of sewer there are 104 air-
shafts, 265 gullies, 15 flashing shafts, 4 tanks, and
26 side entrances. The whole of the sewers were
isolated as far as possible, so as to prevent air cur-
rents passing through thorn either from or to the
adjacent sewers. Theywere, therefore, dependent
upon their own conditions for ventilation. Two
mechanical arrangements were adopted for apply-
ing the charcoal—one being a large sieve with
compartments, the other a series of trays for holding
the charcoal. Wood charcoal was used, broken

nto pieces the size of a filbert. The experi-
ment was commenced on the 14th of July, 1860,
and has been continued more than eighteen
months. During the summer and autumn of
1860 the temperature of the air was low and
the rainfall great. As these had an influence
in checking putrefaction and in scouring the sewers,
Messrs. Letheby and Haywood were unable in
that year to form an opinion of the efficacy of the
filters; but in 1861, when the conditions of the
atmosphere were more favourable for observation,
they were able to gather sufficient facts for a report.
They state they have satisfactorily proved the com-
plete deodorising power of the charcoal. Not only
have there been no complaints from the public of
stenches from the ventilating gratings, but they
have proved by actual observation that the odour
of the sewer gases is not perceptible when they have
traversed the charcoal. Charcoal from the venti-
lators has been submitted to chemical exami-
nation after having been in action from
nine to twenty months, yielding a variety of
compounds of an exceedingly offensive odour.
They state that if the ventilators could be so
arranged as to keep the charcoal dry, it would
not require renewal more frequently than once
a year, but at present many of them have to be
ehanged about once a month. They suggest that
charcoal might be enclosed in the lower compart-
ments of the lamp posts, or the ventilators placed
against the sides of the houses. They next advert
to the effect of the application of charcoal upon the
general ventilation of the sewers themselves--a
point of the highest importance. It is essential,
they say, while lessening the escape of effluvium
into the streets, that the dilution of the gases gene-
rated in the sewers should not be so lessened by the
diminished supply of air as to render the atmos-
phere of the sewers dangerous to the men who work
in them, and that the stench should not find its way
more freely or in a more concentrated state into
the interior of houses by the house drains and other-
wise than it already does. The inferences deduced
from experiments on those points are that the
currents of air in the sewers were somewhat inter-
fered with, and that the ventilation of the sewers
other cases, but the differ-
was not so perfect as in
ences in repict of temperature were extremely
slight. On the other hand, there appeared to have
been no appreciab'e effect on the condition of the

air within the sewers, an far as the experience

and observations of workmen have gone.

The

chymical condition of the internal atmosphere of
the sewers, as proved by analyses, shows a pro-

portion of 79.96 per cent. of nitrogen, 19.51 of

oxygen, and 0.53 of carbonic acid, with traces
of ammonia, marsh gas, and sulphuretted hydro-
gen. They say there is, therefore, abundance

of oxygen to maintain the functions of life, The
cost ,of fitting up the 104 ventilating ,shafts
was nearly £919, or at the rate of about £8
16s. Bd. per ventilator; but, as an experiment is

necessarily more costly than an established systemr

a much less sam maybe taken as a fair average of

the probable expense of extending the process to
the whole city. From the experiments in question

the general conclusions of Dr. Letheby and Mr.
Haywood are, that dry charcoal in the presence of

atmospheric air is a powerful means of destroying
the mephitic gases and vapours of sewers and.

house-drains; that the charcoal filters may be used.
with efficacy in the course of the air channels front

the drains and closets of houses, as well as in the
ventilation of the public sewers ; that in applying

the charcoal contrivances should be used which

offer the least resistance to the free passage of the
air ; and that the situation of the filters is best
when the charcoal is protected from wet and is

easily accessible.

regret to hear
of the well known phil
Cambridge-heath, Hac ney,
DEATH OF Torlf
anthro-
EthitekEdeVa.thD,Ry'esAterdNDayß,EWat IthiEsErDes.rdeWncee,
'e dissenting divine, the Rev. Dr. Andrew Reed. The
El Ede ceased minister had obtained a wide and honourable fame
by his indefatigable efforts in the cause of Christian charity.
The Trieste Gazette, of the 18th, says :—" The
Prince of Wales, who has been at Venice since yesterday,
was immediately after his arrival visited on board the
vessel by the Archdukes Regnier and Joseph, and shortly
after the Prince went to the palace to pay his respects to
the Empress, and remained with her for an hour. The
Prince profits by the opportunity to see all the curiosities
of the city. He sleeps on board."
says the name of the
countries of Europe, are just leaving for Uttcaah in
m,
efrom Den.
A-thousand Mormons, from the three nAmortehern,
by way of Hamburg. The greater pahr
Advertiser
mark, very many of them belonging to t ewell-to-do "nem-
bers of the peasant class.
The ,* taffordshire
of
Staffordshire immediately upon his conduct in
the peace for
Litiheuttheenatitls.ton Savings Bank becoming known
Rev. H. S. Fletcher was: struck out the commission of
ACADEMY OF SCIENCES.—At the last
Sainte-Claire• Devine communical ed a paper on
had discovered for the artificial production of
a mineral of the zeolith family, which abounds in
levyne,aste
nntFti
ehnntßeeghLoi
the island of Skye, also near Glenarm, in Ireland, and Kam-
nitz, in Bohemia. M. Deville's method consists in forming
two solutions, one of silicate of potash, and the other of
aluminate of soda, in such proportions, that the quan-
tities of oxygen contained in the silica and alumina of these
two salts may be to each other in the ratio of two to one.
The solutions, separately introduced into a strong glass
tube, became solid at the common temperature, while the
tube, hermitically closed with the blow-pipe, is being
shaken in order to effect the mixture. On being
heated to 338 deg. Fahr., the substance is formed
into a limpid liquor, which by mere decantation
yields hexagonal crystals, similar to those of
levyne, and having the same chemical composi-
tion.--M. Troost sent in a pa; er on the chemical equivalent
of lithium. The two new metals recently found in the
ores of lithine by spectral analysis might have led to the
belief that the original determination of the _
equi-
valent of lithium might require correction.
and
Troost, therefore, undertook the task of verificateioanra,
ago
has found the equivalent to be 7, as announcedra
cost
by M. Dumas.—M. Leverrier read a note on a
araacei
af a
lar occurrence in astronomy, viz., the disapr,
a star of the 10th magnitude. It had
vbaeeriable. Recently,
nebula discovered by Mr. Hind on the 11thn
retnialrBksed2, near
both the latter and the nebula wdeireg
fact that the nebula
Leverrier and M.
star,
could not find a trace
hAal.ddd'Aisarprepsetaarnedn.ounocendthtehe269.Bi
sed a 12-inch equatorial, and
t's telescopes. At the same
Chacornac both observed
himself ascertained that the
nebula was not
of the nebula, although
date, Mr. Hind Ar oldschmidtG has observed the same
t be found, and ---.
afterwards one of M. FotuhtilYeulu
thing. This "currence promises to overthrow the theory
of 1,1)104 hitherto received.

IMPERIAL PARLIAMENT.

HOUSE OF LORDS--YESTERDAY.

The LORD CHANCELLOR took his seat on the woolsack
at five o'clock.

.......
THE REVISED CODE OF EDUCATION.
Tho Bishop of WINCHESTER presented petitions
against the revised code of education.
PRIVATE BUSINESS.

On the motion of the Earl of COLCHESTER, the following
bills were read a second time :—Caterham Water Works,
Ceylon Railway Company, Great Britain Mutual Life As-
surance, Leeds Water, Deaf and Dumb Poor Asylum, Dun-
dalk and Enniskillen Railway, and Webb and Cray's
Patent.