GREENWICH WEATHER-WISDOM.

IN England everybody notices the weather,
and talks about the weather, and suffers by
the weather, yet very few of us know
anything about it. The changes of our climate
have given us a constant and an insatiable
national disease—consumption; the density
of our winter fog has gained an European
celebrity; whilst the general haziness of the
atmosphere induces an Italian or an American
to doubt whether we are ever indulged with a
real blue sky. ' Good day ' has become the
national salutation; umbrellas, water-proof
clothes and cough mixtures are almost
necessities of English life; yet, despite these
daily and hourly proofs of the importance
of the weather to each and all of us, it is
only within the last ten years that any
effectual steps have been taken in England
to watch the weather and the proximate
elements which regulate its course and
variations.

Yet, in those ten years positive wonders
have been done, and good hope established
that a continuance of patient enquiry will
be rewarded by still further discoveries. To
take a single result it may be mentioned,
that a careful study of the thermometer
has shown that a descent of the temperature
of London from forty-five to thirty-two
degrees, generally kills about 300 persons.
They may not all die in the very week when
the loss of warmth takes place, but the
number of deaths is found to increase to
that extent over the previous average within
a short period after the change. The fall
of temperature, in truth, kills them as
certainly as a well aimed cannon-shot. Our changing
climate or deficient food and shelter has
weathered them for the final stroke, but they
actually die at last of the weather.

Before 1838 several European states less
apt than ourselves to talk about the weather,
had taken it up as a study, and had made
various contributions to the general knowledge
of the subject; but in that year England
began to act. The officials who now and then
emerge from the Admiralty under the title of
the 'Board of Visitors,' to see what is in
progress at the Greenwich Observatory, were
reminded by Mr. Airy, the astronomer royal,
that much good might be done by pursuing a
course of magnetic and meteorological
observations. The officials ' listened and believed.'

The following year saw a wooden fence
pushed out behind the Observatory walls in the
direction of Blackheath, and soon afterwards
a few low-roofed, unpointed, wooden buildings
were dotted over the enclosure. These
structures are small enough and humble enough to
outward view, yet they contain some most
beautifully constructed instruments, and have
been the scene of a series of observations and
discoveries of the greatest interest and value.
The stray holiday visitor to Greenwich Park,
who feels tempted to look over the wooden
paling sees only a series of deal sheds, upon a
rough grass-plat; a mast some 80 feet high,
steadied by ropes, and having a lanthorn at
the top, and a windlass below; and if he looks
closer he perceives a small inner enclosure
surrounded by a dwarf fence, an upright stand
with a moveable top sheltering a collection of
thermometers, and here and there a pile of
planks and unused partitioning that helps to
give the place an appearance of temporary
expediency—an aspect something between
a collection of emigrant's cottages and the
yard of a dealer in second-hand building
materials. But,—as was said when speaking of
the Astronomical Observatory,—Greenwich is
a practical place, and not one prepared for show.
Science, like virtue, does not require a palace
for a dwelling-place. In this collection of
deal houses during the last ten years Nature
has been constantly watched, and interrogated
with the zeal and patience which alone can
glean a knowledge of her secrets. And the
results of those watches, kept at all hours,
and in all weathers, are curious in the
extreme: but before we ask what they are, let
us cross the barrier, and see with what tools
the weather-students work.

The main building is built in the form
of a cross, with its chief front to the
magnetic north. It is formed of wood; all iron
and other metals being carefully excluded;
for its purpose is to contain three large
magnets, which have to be isolated from
all influence likely to interfere with their
truthful action. In three arms of the cross
these magnets are suspended by bands of
unwrought, untwisted silk. In the fourth arm
is a sort of double window filled with
apparatus for receiving the electricity collected at
the top of the mast which stands close by.
Thus in this wooden shed we find one portion
devoted to electricity—to the detection and
registry of the stray lightning of the
atmosphere—and the other three to a set of
instruments that feel the influence and register
the variations of the magnetic changes in the
condition of the air. ' True as the needle to
the pole,' is the burden of an old song, which
now shows how little our forefathers knew
about this same needle, which, in truth, has
a much steadier character than it deserves.
Let all who still have faith in the legend go to
the magnet-house, and when they have seen
the vagaries there displayed, they will have
but a poor idea of Mr. Charles Dibdin's sea-
heroes whose constancy is declared to have been
as true as their compasses were to the north.

Upon entering the magnet-house, the first
object that attracts attention are the jars to
which the electricity is brought down. The
fluid is collected, as just stated, by a conductor
running from the top of the mast outside. In
order that not the slightest portion may be
lost in its progress down, a lamp is kept
constantly burning near the top of the pole, the
light of which keeps warm and dry a body of
glass that cuts off all communication between