262 
ON THERMOMETER STANDS. 
who take an interest in the changes of the weather; and, it is very 
attend to this subject, as it 
them, and, by taking pro¬ 
keep regular weather reg- 
be of the greatest interest 
conferred on the scientific 
Thermometers for com¬ 
at a certain height from the 
face the north (except those 
ister the maximum temp- 
which should face the 
influenced by radiated heat, 
heat, such as is communi- 
hy absorption of heat from 
which the thermometer is 
they should be situated 
sage of air. 
that a thermometer is placed 
certained that an inch occa- 
of a few degrees. Thermo- 
heights do not vary much 
weather; hut, with a cloud- 
very great; as an illustra- 
ample, viz.—March 13, 
thermometer on the grass 
above the grass it stood 15°, 
grass at 18*5°. Here is a 
times as much between the 
and two feet 
tween the grass 
of 14° or four 
With respect to 
mometers, we 
stance which oc- 
same time as the 
desirable that gardeners should 
is an all-important one to 
per precautions, they might 
isters, which would not only 
to themselves, hut a benefit 
world. 
parison should all be placed 
ground; they should all 
which are required to reg- 
erature in the sunshine, 
south); they should not he 
by currents, by reflected 
cated from an opposite wall, 
the wall or wood-work to 
attached; and, in short, 
where there is a free pas- 
With regard to the height 
aboye the ground, it is as- 
sionally makes a difference 
meters placed at various 
from each other in cloudy 
%J 
less sky the difference is 
tion we shall quote an ex- 
1845,* 9h. 10m. p.m., a 
had fallen to 4:’5°, two feet 
and seven feet above the 
difference of 10f°, or three 
temperature of the grass 
above it; and be- 
and seven feet, 
times as much, 
the aspect of ther- 
shall give an in¬ 
curred at the 
last observation. 
A thermometer placed fourteen feet above the ground, with a south-east aspect was 15°, -with a north 
aspect 17°, with a north-east aspect 18°, and with a south-west aspect 19°. 
It cannot be expected that thermometers, placed as they generally are, may be depended upon, 
some facing the north, others the south; some the north-east, others the north-west; some three to five 
feet above the ground, others ten to twenty; some sheltered by a high wall, others by low palings; 
* See “ Treatise on Atmospheric Phenomena;” by E. J. Lowe, Esq., F.R.A.S. Page 350. 
