The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1871-08-06


into which the storm will pass, ana occasionally
even give premoni,on OF ITS breaking up INTO twu
portions eacn drawn in different directions
The more violent wiuds generally follow In the
rear ana the south side OF the advancing area OF
lowest pressure those That precede the progress
ina area may Olten be more dangerous, hOWeve e
because OF tho accompanying ram, fog, &c. yhe
latter winds are preceded by the cirrus ana threat
cnlng storm clouds; the ram that accompanies or
follows these generally abatcs ana thus gives waru-
Ing OF the strong cleariny-un Winds.
rne rapdity OF progression oc the area Of cloud
and ram varies from fifteen TO sixty miles In an
hour, the actual We octy varying with the influence
oil moisture, as explained In previous section.
fhe average velocity or the currcnts winch deter
mine tue general direction OF tue progress OF the
nucleus Of the storm, varies from twenty to forty
miles hourly ana rarely reaches The higher limit.
Ihe changes that are now tnrice daily reported
rom Mount washington frequently afford inoica
Iil ar currents, and hence afford sure Fremont
tlons OF g change IN the general character OF the
weather, and WITH great frequency foreshadoW the
storms that pass directly over that region.
IL IS by increasing the mountain stations and by
AIDING such balloon Observations as can be made
ana specially by the study OF the forms, changes
motions, height and velocity OF the clouds ana Of
the optical phenomena OF the atmosphere that we
hope eventually arrive al a full kno Wedge OF the
upper regions OF the air. Wnero the severe storms
are propagated.
INSTRUMENTAL INDIcArioHs
IL should always be remembered that CHANGES in
weather generally give SeuS OF their cOming tor the
inslruments are affected before the wird actually
peEins 10 olow or the ram 10 fall: thus they may he
said to enable us to feel the pulse Of the atuus.
phere 1t must not be forgotten that the length Of
L!iuc Wnicu passes between the first apDeara
change OF weather and its actual setting in are
not the same. IL Is much greater wnen south
west wind is gong 20 suceecda northeast Wind
IMAM when Inc opposite change f. abOus To take
place. II the barometer rises steadily apOvc IFS
mean height While The weather gels coider and
northeasterly winds, or less wilma, less ram or
snow may generally he expected TN the
trary, II tne barometer Tails while the weather
gets warmer ana The air becomes damper, WIND
and rain may be looked Tor from the southeast,
south or southwest
Ma
I changes OF weather.
Z II the weather gets warmer while the barome.
/ ter is nigh and tue wind northeasteriy, we may
look for shut OF glnd 10 the soIti On tae
other hand, the weather sometimes becomes
i colder wnile tue WIND is southwcster1y and the
/ barometer low, ana then we may look Tor
sudden squat, OF perhaps storm from the north
west. Tho most striking exceptions 10 tie
| rules are those noticed By Admiral, FiTZrOy.
They occnr with northeast WINDS, which
ally during gales. although the barometer may
be high ana rising ON the other hand, when
the wind IL northeastern and LIGHT and the
la barometer begins 10 ia, rain may ser IN d aore
the wind changes 10 east or easl-souihcast.
Besides these rules Tor the Instruments there
is a rule ahout The way In which tae wind
changes which Is very important II Is well
known TO every sailor, and Is contained IN the
When the wind shirts against the sun.
Trust It not for back will run.
the wind usually shifts with the SUM- e
from lett To right IN the northern hemisphere.
I 4 change In tins direction Is called vecriny
L Thus an east wind shifts to west thrOupn
4 southeast, south and southwest, snd west
/ WIND shifts TO cast through northwest. north
j3 and northeast. II the wud shifts the CppoSue
way, VIZ, IRON west TO southwest, soutn and
I southeast, the changes called backing. ana it
seldom occurs unless when the weather Is I'M
Settled.
such are some OF the principal laws which
having been tested IN the severe crIciDIe Of
4 thirty years acute and precise observation are
unanimously accepted by nlcieor0iogsts all
over the world.
! TO fedfed, Reid, Ferret, Colin. Espy Fiig
! row. Blocgel, Buchan, Buys, BALLOT ana many
IL others oequa merit IN meteoroogy Il tue world
| chiefly H. deOted for TINS knowledge.
l The laDors Of the Chef signal Officer and hts
assistants found Ut their commencement THIS
knowledge scattered aud discounted.
IL cannot reasonably be expected that. IN the
I, short space OF nJBe since our Weather Bureau
was organized under General Myer, exact lntci-
le lgence unlallng correctness OF lore casts can
~ be furnished. NeteOrOOgy t. yet but n science
OF ''prOhaDilesn not OF ccrisinties IL ~ vet
III its infancy, and lt cainot DC severely judged
as the oder sciences, in which everything can
be Instantly and easily tested in tue laboratory
ly manual experiment.
Although the signal Onlce IL not chargeable
10y law with doing anything more than an.
\, noancing the approach Of the most dangerous
storms It's bulletins OF the general weather are
universally sought altet ana respected. and ITS
sphere oil influence ana usefulness IL every day
widening It's prospects OK increasing certainty
IN It's processes OF investigation and It's pun
lished storm warnings arc continually imrrov.
ing. There seems To have been no haste 10
carve out or act upon crude ana iacllul theories
O the atmosphere. II its chez has mad tn move
forward in Tue dark be appears 10 have felt hi4
way very carefully. lie has evidently Pnulaied
the wisdom when led to the selection of the IA
nous lines Of Torres Vedras, IN the Old Pennsu.
lar campalgn-a position from winch Inc occu-
pant cannot be forced 10 retreat and which gives
him every facility for an advance.