Year: 1871

HOW 1T CONCERNS THE FARMER.


Prof Tyndal, in recent lecture on radia-
tion said: "a cobweb spread over blossom
Is sufficient to protect it from nightly chill"
In this rather fanciful expression we have a
hint OF great fact in natural science. The
pest OF 1t Is in the practical bearing it has up
on the common things of every day farm
life.


Let US explain some of Professor Tyndaps
applied science as it concerns agriculture.
Radiation refers to heat. Without lgoing in
to an examination Of the quality and general
properties of heat, let us look at its tmost re-
markable property-radiation. II we hea. a
brick in the fire and then place it on the
ground its heat begins to radiate in every di-
rection. By holding the hand beside it we
perceive the escaping heat. By placing the
hand over it we notice an increased radiation.
II we remove the brick and examine the
ground we find 1t also has been heated,
though in less degree. Had we placed the
brick upon block OF ice radiation would
have gone on as before, and at a much great
er speed.


From those common things farm life has to





proceeds necessarily. When we consider that
every plant or animal that lives must main-
tain certain fixed temperature or die, the
practical meaning OF the applied science of ra-
diation becomes plain. The turnip will not
thrive in temperature of less than 40 de-
grees; no flower will bloom IL the air stands
below 55 degrees; no COW or horse can live in
health unless its blood can stand at blood
heat, and every child that lives must be pro-
toI h., skoII olo
thatlts animal heat may not tall beow the
happy 0S degrees


To return to our experimental brick. There
is nothing like experiment Experiments
show us the working of natural laws. Ap.
piled science is nothing more than carrying
the results OF pure experiment into real life.


Heat the lick and this time place it on the
hearth in the warm kitchen. Radiation
takes place as before, but at a slower rate.
If it is chilled in half an honr outside, here it
| will be perhaps au hour cooling, and even
| then will not become so cool; that is, if it
cools to 40 degrees out of doors, here it may
not fall below 45 degrees.


Notice this little fact and stow it away in


your mind. Presently you shall see IFS ap-
plication to your cows in your barn. There
are dollars and cents in the latter matter


Now heat three bricks and ask the house,
keeper for piece of woolen cloth, a muslin
handkerchief and All old newspaper Now
lift ore brick from the stove with the tong5
and roll it up in the woollen. Twine the
handkerchief round another brick, and wrap
up the other tightly in the paper.


Meanwhile let ms examine another matter.
Heat brick and drop it into pail Of water.


Take it out at once, aud notice how quickly
it has cooled.


To return TO our packed bricks. We find
the woolen covered one at perhaps one hun
dred and fifty degrees, and the muslin-cover-
ed one at sixty degrees. TO look at the prac-
teal side of this we see that radiation pro-


ceeds at different rates through different SUBJ
stances. Suppose the brick child. His an-
| imal heat Iwould have raaiated through the
| muslin quickly and been almost entlely saw
ed by the woollen. @
AS another experiment wrap the woolen
round a hot brick in such way that one face
of the brick is exposed to the air. Lay it


down exposed side up. Tear off a bit OF the


newspaper slightly larger than the brick, and
lay it upon hot brick. Roll up more paper
and make a cap or tent over mother hot


brick We find that the woollen-covered one


is the coolest this time. The one with the
paper shade over it less cool, and The with the
paper hood warmest of all. Wherefore? Sim
ply beeanse radiation into the air, when it is
free to move upward, is most rapid. The


wooiien about the sides is nearly useless


while the top is exposed. The bit of paper,
though it only covers tb1 top, does better, as
the upward movement of the air about it is in
measure prevented. The paper hood being
airtieht locks in a cone-shaped mass OF air,
The air, unable to escape with its heat
stores it up, and reradiates it again, and so
checks the cooling Of the brick.


To save plant from early frost protect 1t
from the top. Radiation Is most active up
ward. A paper screen over the top will ac-
csmplsh mole than woollen wrap round
the Sides paper hood would be best of all.
Make your barn tight, especially about the
top, xpd your cattle will eat less, be in a bet
ter condition, and bring a larger return in
| milk or meat. Radiation from their bodies
| being reduced, health, comfort and happiness
| will return TO theD, and money to you. A
| barn full Of cracks is an offence against sci


ence and your pocket.


A small blanket on the top of horses


back will do more good thaH a large one bad
| ly fastened on.


hadlatlon takes place more rapidly through
water than air. Radiation through aoneo1s
yap0r is slow. Keep aii the feet on Won,
place dry, be thty sh0d with iron or leather
10 save your green house coal keep the air
inside damp. Radiation is slow in damn at
nOsphere; quick in dry one. To save YOUR
vineyard from an early frost build fires of
green wood among the vines at night. The
| aqueous Vapor causal by the smouIdering
| wood will It as blanket and perhaps save
| the crop. A fire OF dry wood, warm II ever SO
iercely, will.not do halt so much good.
| Apply these few facts to your every day
life on the farm and you will find money in