The Sun.
London, England, 1850-04-09 00:00:00

THE SUN,

raise soap. If our readers in London observe their
habits in washing, they will perceive that the princi-
pal geantity of the water is used by them not as a
cleanser, but merely for the purposes of rinsing off
the very sparing amount employed for detergent pur-
poses. In London we do not wash ourselves in but
out of the basin. A small quantity of water is
taken on the hands and saturated with soap so as to
form a lather ; the ablution is now made with
this quantity, and the water in the basin is only used
to rinse it off. The process of washing with soft
water is entirely different, the whole quantity being
applied as a detergent. To illustrate this difference
an experiment may be made by washing the hands
alternately in rain and then in hard water,
such as that supplied to London ; and the value
of the soft water for the purposes of wash-
ing ssill be at once recognised. Even with-
out soap, the soft water moistens the hand, while
hard water flows off, just as if the skin had been
smeared with oil. Now, although the soap may be
economized in personal ablution by the uncomforta-
ble method here described, it is impossible to obtain
this economy in the washing of linen. In this case,
the whole of the water must be saturated
with soap before it is available. Soda is, to a
certain extent, substituted with a view to economy,
as much as 30,0001. worth of soda being
annually used in the metropolis to compensate for the
hard quality of the water ; and, perhaps, as an ap-
proximative calculation, 200,0001. worth of soap is
annually wasted without being useful as a detergent.
This enormous tax on the community results from the
hardness both of the well and river water ; the for-
mer being generally much harder than the latter.
But this expense, large as it may seem, is not the
only consequence of a bad water supply. The labour
required to wash with hard water is very much greater
than that necessary when it is soft, this labour being
represented in the excessive charges for washing. In
fact, extraordinary as it may appear, it has recently
been shown in evidence before the General Board of
Health that the washerwoman's interest in the com-
munity is actually greater than that of the cotton-
spinner, with all his enormous capital. An instance of
this will suffice to show our meaning : a gentleman
buys one dozen shirts at a cost of 4/., three of
these are washed every week, the charge being four-
pence each, making an annual account of 21. 12s.
The set of shirts, with careful management, lasts for
three years, and has cost in washing 71. 16s. The
cotton-spinner's interest in the shirts and that of the
shirt-maker's combined, did not exceed 41., while the
washerwoman's interest is nearly double. A consider-
able portion of this amount is unavoidable; but a
very large part is due to the excessive charges
for washing rendered necessary by the waste of soap
and increased labour required for cleansing. A
family in London, with au annual income of 600/.,
spends about one-twelfth of the amount, or 50/,
in the expenses of the laundry. On an average,
every person in London, rich and poor, spends
one shilling per week, or fifty-two shillings
a year for washing. Hence at least five million two
hundred thousand pounds is the annual amount
expended in the metropolis alone for this purpose.
Yet, large as this amount is—and it matters not
whether it be represented in the labours of house-
hold
washing or that of the professed laundress—
it is obvious that the greatest part of it is
expended in actual labour, for the washerwoman
is rarely a rich or even a thriving person. Hence
it follows that this labour, barely remunerative as
it is, must be made excessive from some extrane-
ous cause ; for it is found by experience that one-
half the charge is ample compensation in a country
district supplied with soft water. The tear and
wear of clothes by the system necessary for washing
in hard water, is very important in the economical
consideration of the question. The difference in this
respect, between hard and soft water, is very striking.
It has been calculated that the extra cost to ladies in
London in the one article of collars, by the unne-
cessary tear and wear, as compared with country
districts, is not less than, but probably much exceeds,
20,000/.

We now proceed to draw attention to the inconve-
nience of hard water in cooking. It is well known
that greens, peas, French beans, and other green
vegetables, lose much of their delicate colour by
being boiled in hard water. They not only
become yellow, but assume a shrivelled and disa-
greeable appearance, losing much of their delicacy to
the taste. For making tea the evil is still more ob-
vious. It is extremely difficult to obtain a good in-
fusion of tea with hard water, however much may be
wasted in the attempt. We endeavour to overcome
the difficulty by the addition of soda, but the tea thus
made is always inferior. One reason of this is, that
it is difficult to adjust the quantity of the soda. Tea
contains nearly 16 per cent, of cheese or casein, and
this dissolves in water rendered alkaline by soda ; and
although the nutritous qualities are increased by this
solution, the delicacy of the flavour is impaired. The
water commonly used in London requires, at the very
least, one-fifth more tea to produce an infusion of the
same strength as that obtained by soft water. This,
calculated un the whole amount of tea consumed in
London, resolves itself into a pecuniary consideration
of great magnitude.
The effect of hard water upon the health of the
lower animals is also very obvious.—The Ladies' Com-
panion.

THE EXPECTED GREAT COMET.

TO THE EDITOR OF TLIE TIMES.

Sir,—ln my letter addressed to you on the 7th
of March, which appeared in the Times on the
follJwing day, I mentioned the possibility of a con-
siderable delay in the return of the comet of 1264
and 1556, owing to the attraction of the larger
planets, particularly Jupiter and Saturn. I have just
received from M. Bomme, of Middelburg, a very
complete memoir on this subject, which has been re-
cently published by the Royal Institute of Sciences
in the Netherlands. It is the result of a long and
laborious series of calculations, performed on the most
approved methods of modern mathematicians. The
conclusions being of general interest, I may very
briefly state them here, as the paper itself is not likely
to fall under the notice of many English readers.
In order to predict the time of reappearance of a
comet moving in an elliptic orbit, with allowance
for the attractions of the planets, it is necssary that
we should know the precise time of revolution
corresponding to some past epoch (as, for instance,
the previous perihelion passage), or the period
which the comet would require to perform its circuit
round the sun, if all planetary disturbances were to
cease from that moment. The comet in question was
observed in 1264 and 1556, and the interval between
the perihelion passages in those years amounted to
106,567 days, or 2911 years; but this tells us nothing
with respect to the length of period corresponding
to the ellipse described at the instant of perihelion,
either in 1264 and 1556, since it includes the united
effects of planetary perturbations between
those years. Therefore, before we can ascertain the
epoch of the next return, we must calculate the
amount of acceleration or retardation due to the
disturbances between 1264 or 1556, which
being applied to the above period gives us
the exact time of revolution of the comet at
the moment of perihelion passage in the former year,
and hence we ascertain the period in 1556. Having
found this, we can calculate how much it would be
increased or diminished by planetary attraction up to
the present time, and thus determine the date of the
next arrival at perihelion. This is essentially the
method adopted by 111, Bomme,-and he bas performed
a great part of the computations in duplicate—first,
with the elements of Halley, in 1556, found in all our
catalogues of cometary orbits, and, again, with my
final element, published in the " Astronomische
Nachrichteit" of Professor Schumacher, the "Comptes
Rendus" of the French Institute, the "Notices" of
the Royal Astronomical Society, and elsewhere; this
last set only came to M. Bomme's knowledge when
he had nearly completed the first series of cal-
culations, but, as he considered them more
exact, he went through the greater part of
the work again. With these elements, taking into
account the attraction of Jupiter, Saturn, Uranus,
and Neptune between 1264 and the present time, and
of Venus and the Earth in 1556, it is found that
the length of the comet's revolution at the time of
perihelion passage in 1264 was 110,644 days, or
302,922 years, and in 1556, 112,561 days, or 308,169
years ; that the effects of perturbation will diminish this
period 2,166 days, and therefore the present revolu-
tion will occupy 110,395 days, or 3021 years, so that
the comet will return again to its perihelion on the
2d of August, 1858, and will then be moving in an
period.
of the m
'With
comet
Halley'setin
elelements,iPse o
thetruell2 timeßs
1566 was 112,943 days, and the perturbations should
diminish the ensuing period about 1,797 days, whence
we find the next perihelion passage will occur on
August 22, 1860.
Thus M. Bomme concludes that if the true ele-
ments of the orbit in 1556 were within the limits as-
signed by Halley's calculation and my own, the
comet will appear again between 1858 and 1860.
The main cause of this uncertainty is the difference
between the two determinations of the positions of the
.major axis, or line of Apsides, in 1556. Halley
fixes the perihelion in longitude 278 deg. 50 min.,
while I place it in longitude 274 deg. 15 min., de-
viating 4 deg. 35 min. Having expended a good deal
of time and trouble some years ago on the calcula-
tions for my orbit, I believe I may safely state that
the utmost allowance that can be made for error in
the position of the major axis does not exceed
four degrees, so that it is probable the time
fixed for the return of the comet by my elements
(August 2, 1858) must be within two years of the
truth, and therefore we have but little chance of seeing
it within six years from this time. At any rate, the
supposed delay in its re-appearance is fully accounted
for through the zeal and industry of M. Bornme,
whose calculations, as regards extent and intricacy,
may vie with those of Clairault and Rosenberger for
Halley's comet.