New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1891-06-26
p,yoYNc orr HOW HOT IT rs.

,oh ,,ootbnr 10 has prevailed over most OF
the country recently, it is not so simple ni"',ei
os one might suppose to ascertain the eAacO III
tensitv of the heat from which people are sui'er-
inc Owing 70 slight inequalities in the size oil
tho mercurial thread in different parts OF q ther-
mometer-tube, two instruments may read alike 40
an or 70 and vet be two or three degrees apart
nm in the nineties. In fact, very cheap Their
mometer will sometimes vary from the stanu'iu
even more than this at some part Oh the scaie'
Other discrepancies in the record may arise
from defective methods of exposure. Two lnsuu-
ments whose accuracy has been carefully tested
and proven may yield dissmilar results at the
same identical moment If hung without special
care Most people consider that all is done that
is necessary if only the direct sunlight Is Kept
from falling on the quicksilver. This precauuon
"a NOT enough. Extra heat may be conveyed TO
the instrument by the material against which IL
rests; O post, wall, windOw-casing or other DacK-
ing. some adjacent portion Of which Is warmeu
by the sunshine. Or on the other hand, heaVy
masonry well shaded as on the north slde Oh
room. may be so slow in acquiring warmth from
the atmosphere as to retard the proper rise Oh the
mercury in thermometer hanging against IT,
Another influence Of which due account Is noU
usuollv taken is the reflection Of heat upon
shaded thermometer from glass, curtains fronts
90 huildings or other surfaces near by. pave
ment will often in this manner add senslbly TO
the heat few feet above It's level, while rod
or two higher up it would not affect the temperac
ture at ALL A steam-boiler under the sidewalk,
air escaping through gratings from an engine
room. and the warmth radiated from the bodies
of peoplc standing close to Il thermometer are
also liable TO increase the readings, the tempera-
ture boom in such cases being in the strictest
,lorn hCor m
Iect data to be used in comparing one season or
nlace with another, the thermometer is generally
suspeuded in an Enclosure with Slated Sides
which exclude both direct and reflected heat
ravs and preclude the conducting Of heat by any
substance except the air. This is allowed to flow
in and out and to circulate around the instru-
ment freely And the observer makes his reading
rapdly and with bated breath For popular in
formation, however, less scientifically exposed
instrument, If only trustworthy, is probably the
more satisfactory one 1t reveals more faithfully
thnn thermometer better sheltered the conditions
under which sweltering humanity percgriDates.
Again. there is this complication to be consid-
cred Part of the time the pedestrian is in the
shade, like the thermometer, and part of the time
In the sunshine, where it is hotter OF course
no such differences of temperature would ordi-
narily exist as between the shade and "sun"
thermometers of an observatory, which is often
40 or so degrees; for the latter instrument has q
backened bulb and is inclosed in vacuum. Out
In the open air of the street, however, it may
easily be . or 90 degrees hotter in the sunshine
than in the shade. But, further, under the direct
rays. the amount OF caloric affecting the bodily
comfort of any individual will vary somewhat
with the texture and color Of his hat and clothing.
Black absorbs heat more readily than white;
duh surface better than polished one; and there
are countless gradations in peoples apparel be-
tween these extremes, while the glistening Their
mometer-tube remains of one material and APP
pearance With all these facts in view, and even
without reference to the humidity of the air. one
cannot avoid the conviction that facilities for
finding ont how hot it is, these days, are not all
that could be desired