ICE 
some degree, equalizes the temperature, 
and partly for other reasons. The compa- 
rative intensity of the southern summer and 
winter is not exactly kn6wn ; but in the 
island of New Georgia, the summer is said 
to be extremely cold. 
The northern ice extends about 9° from 
the pole; the southern 18° or 20°; in some 
parts even 30° ; and floating ice has occa- 
sionally been found in both hemispheres as 
far as 40° from the poles, and sometimes, as 
it has been said, even in latitude 41° or 42°. 
Between 5 and 60° south latitude, the 
snow lies oil the ground, at the sea-side, 
throughout the summer. The line of per- 
petual congelation is three miles above the 
surface at the equator, where the mean 
heat is 81°; at Teneriffe, in latitude 28° 
two miles ; in the latitude of London, a lit- 
tle more than a mile ; and in latitude 80° 
north, only 1,200 feet. At the pole, ac- 
cording to the analogy deduced by Mr. 
Kirwan, from a comparison of various ob- 
servations, the mean temperature should be 
31°. In London, the mean temperature is 
50"; at Rome and at Montpelier, a little 
more than 60° ; in the island of Madeira, 
TO” ; and in Jamaica, 80 s . 
Ice house, a building contrived to pre- 
serve ice for the use of a family in the sum- 
mer season. Ice houses are more generally 
used in warm countries, than with us, parti- 
cularly in Italy, where the meanest person 
•who rents a house, has his vault or cellar for 
ice. However, as ice is much more used 
in England than it was formerly, it may 
not be amiss to give some directions for the 
choice of their situation, for the manner of 
building them, and for the management of 
the ice. 
As to the situation, it ought to be placed 
upon a dry spot of ground, because wher- 
ever there is moisture, the ice will melt; 
therefore, in all strong lands which retain 
the wet, too much pains cannot be taken to 
make drains all round them. The place 
should also be elevated, and as much ex. 
posed to the sun and air as possible. 
As to the figure of the building, that may 
be according to the fancy of the owner; 
but a circular form is most proper tor the 
well in which the ice is to be preserved ; 
which should be of a size and depth propor- 
tionable to the quantity to be kept ; for it is 
proper to have it large enough to contain 
ice for two years consumption, so that if a 
mild winter should happen, in which little 
or no ice is to be. had, there may be a stock 
to supply the want. At the bottom of the 
ICE 
well there should be a space of about two 
feet deep left to receive any moisture that 
may drain from the ice ; over this space 
should be placed a strong wooden grate, 
and from thence a small drain should be 
laid under ground, to carry off the wet. 
The sides of the well should be built with 
brick, at least two bricks thick; for the 
thicker it is, the less danger there will be 
of the well being affected by any external 
cause. AVlien the well is brought up within 
three feet of the surface, there should be 
another outer arch or wall begun, which 
should be carried up to the hfeight of the 
top of the intended arch of the well ; and if 
there be a second arch turned over this 
wail, it will add to the goodness of the 
house : the roof must be high enough above 
the inner arch to admit of a door-way to 
get out the ice. If the building is to be co- 
vered with slates or tiles, reeds should be 
laid considerably thick under them, to 
keep out the sun and external air; and if 
these reeds are laid the thickness of six or 
eight inches, and plastered over witli lime 
and hair, there will be no danger of the 
heat getting through them. The external 
wall may be built in what form the pro- 
prietor pleases; and as these ice-houses are 
placed in gardens, they are sometimes so 
contrived as to have an liandsome alcove 
seat in front, with a small door behind it, 
through which a person might enter to 
take out the ice ; and a large door on the 
other side, fronting the north, with a porch 
wide enough for a small cart to back in, in 
order to shoot down the ice near the mouth 
of the well, which need not be more than 
two feet in diameter, and a stone so con- 
trived as to shut it up in the exactest man- 
ner: all the vacant space above and be- 
tween this and the large door should be 
filled up with straw. Tiie building thus 
finished should have time to dry before the 
ice is put into it. 
It is to be observed, that upon the wood- 
en grate, at the bottom of the well, there 
should be laid some small faggots, and if 
upon these a layer of reeds is placed smooth 
for the ice to lie upon, it will be better 
than straw, which is commonly used. As 
to the choice of the ice, the thinner it is, 
the easier it may be broken to powder; for 
the smaller it is broken, the better it will 
unite when put into the well. In putting it 
in, care must be taken to ram it as close as 
possible ; and also to allow a vacancy of 
about two inches, all round, next the side of 
the well, to give passage to any moisture 
