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ON THE PINUS AUSTRIACA. 
or evaporated state. To repel the first, thick walls and roofs formed of 
materials the least conductive of heat 'are necessary; and to guard 
against the ascent of subterranean heat, a floor of thick stone pavement 
should be laid on a substantial foundation of compactly-rammed clay. 
Where there is a natural foundation of rock or clay, common brick 
pavement may suffice. 
Besides ice-houses, there are what are called hovels, which are said 
to keep ice as well as those built with bricks or stone and mortar. 
These hovels have a frame formed of any rough scantling, of the 
required size, and either round or square. The floor should be some¬ 
what higher than the surrounding surface, and its place should be shel¬ 
tered and shady. An old chalk or gravel pit in a wood is an eligible 
place. The walls and roof should be formed of wheat stubble, laid and 
bound on as compactly as possible, and the thicker the better; because 
the thicker this is the better the ice will keep. To prevent rain sink¬ 
ing into the fabric, both the walls and roof should be well and thickly 
thatched in the manner of a corn-rick, forming a cone with a very 
large base. The body of* broken ice within should be piled also in a 
conical form, and the vacant space above the ice should be well filled 
with loose straw, to exclude all air from the interior. 
The entrance should be towards the north, and no larger than it 
absolutely need be for getting in and out the ice: the door being, 
when shut, always covered up with litter. Such hovels are common 
in the United States of America, and are said to answer the purpose 
well. 
The above section, b, is that of a circular ice-house, supposed to be 
formed in the north brow of a hill; or, if built on level ground, to be 
deeply covered by earth, or other thick roofing. It is not necessary 
that it should be circular, as an arched vault of any length might do 
equally well; but the larger the body of ice, the less rapidly will it 
melt, if sufficiently broken and secured from air. 
On the Pinus Austriaca, or Black Fir of Austria. By Mr. 
Charles Lawson, seedsman to the Highland and Agricultural Society 
of Scotland. 
“ Two years ago my attention was directed to the Pinus Austriaca , 
or Black Fir of Austria, from seeing a description of it in a work by 
Francis Hoss, Professor of the Science of Forestry in the Imperial 
School of Forestry at Mariabrun, near Vienna, entitled ‘ Guidance to 
determine the Trees and Shrubs of Austria;’ in which, by a long and 
minute botanical description, he proves this fir to differ essentially from 
all the others described by him, in that it naturally thrives best on 
