North Iowa times. [volume] (McGregor, Iowa) 1867-current, 1867-11-13
WHOLE No. 578.
Correspondence.

Messrs. Editors Some time ago in
serted in the Prairie du Chen Courier ar
article on Barmometers, as an instrument
for foretelling the weather, and strongly
recommending them to every farmer-be
ing almost as useful an appendage to him
as any other implement. e -.t
now beg through the TINES to make Q
few observations on another instrumen,
for giving fore-knowledge of the wealth
er; though perhaps not quite so good as
the Barometer, yet sufficiently for the pur.
pose, and much cheaper, as every man can
make them. mean the Hygrometer
| This instrument is contrivance by which
we are enabled to measure the degrees OF
dryness or moisture of the atmosphere.
1t is nesessary to associate with it the
Thermometer and Barometer, in order to
be enabled to unravel the complication ol
different causes which influence the varia.
tions of the atmosphere; and it is only by
long series of observations, made by
these instruments, together with all the
indications deduced from the state of the
heavens, that we can obtain such data as
will enable us to prognosticate the tempo.
rary changes ard to arrive at plausible
theory upon this interesting subject.
There are various sorts of hygrometers
for whatever body either swells or shrinks
by moisture or dryness may be formed in
to hygrometer; such as most kinds OF
wood, particularly white wood, as poplar,
birch, pine, &c. And on this principle it
it that wedges of we'll dried wood are en-
ployed for cleaving or raising rocks, for,
in proportion as the moisture of dew, rain
or water applied to them they swell and
overcome an inconceivable resistance.
Ropes or strings made of hemp, flax, OF
any other vegetable substance, become
also hygrometers. .. 49,. notice.
Stretch cord or fddle-string, fastened
at one end over pulley, and to the other
end tie weight; this will rise or fall as
the air becomes dry or moist, and conse-
quently be a hygrometer. na1'gn
| Animal substances, as cat-gut, whale.
bone, &C., twisted and dried, answer the
same purpose, as performers on stringed
instruments often find to their cost. 1
A very simple hygrometer may be form
ed by means Of a faxen line, or say well
manufactured whip-cord, FIVE feet long
and having a graduated scale fixed to an
index moving on fulcrum. The length
of the index, from the fulcrum to the point
should be ten inches: that of the lever
from the fulcrum to the middle of the eye
to which the cord is fixed-two and 6
half. The air becoming moist, the cord
imbibes its moisture; the line in conse.
quence is shortened and the index rises
On the contrary--the air becoming dry
the cord discharges its moisture, lengthens
and the index falls. An hygrometer o.
this kind may be constructed to be very
useful to farmers as most valuable ora
Gle. By placing it on fallow ground, il
may be actuated by the perspiration of thu
earth; among vegetables, by vegetable
perspiration. #aa .sss.
Another simple Hygrometer may be
made as follows: Take well-dried whip
cord and fix a plummer to the end of it
and the whole be hung against wainscot
draw line under it exactly where thu
plummer reaches. In very moderate O,
even rainy weather it will be found to rist
above such line, and to sink below it when
the weather is likely to become fair.
A great misfortune, however, which at
tends the use Of all these substantials is
that by use they become sensibly less and
less accurate, SO as at length not to under.
90 any visible alteration from the diferen,
states of the air, in regard to dryness o,
moisture. On this account, sponge may
be prepared, as being less liable to be SC
changed. To prepare the sponge, first
wash it in water, and when dry, wash i,
again in water wherein sal ,ammoniac, OF
salt water has been dissolved let it dry
again. lsow, if the air becomes moist, the
sponge will grow heavier; and if dry, i,
will become lighter. .....-
If, however, the observer be desirous OF
instituting very accurate experiments, il
will be advisable to procure the whalebone
hygrometer, originally invented by NJ. dc
Luce, q Frenchman, which is esteemed
enc Of the best now in use.
a5 THos. s. Shaw.
Eoekr,or No. 1Cc- ..t.....