FIR TREE. 
221 
are called masts ; under those dimensions spars , or, 
in England, Norway masts ; because Norway ex- 
ports no trees more than eighteen inches in diame- 
ter. The English merchants, who contract with 
government, buy the masts from the burghers of 
Riga; and great skill is required in distinguishing 
those that are sound throughout, from those which 
are in the least internally decayed. They are usually 
from seventy to eighty feet in length.” 
It is not from the Pinus sylvestris alone that 
good masts are obtained, since the Weymouth pine 
( Pinus Sir aims Linn.) is almost as famous for this 
sort of merchandize. Large and extensive woods 
of these trees are to be found in America, between 
the forty-second and forty-fifth degree of northern 
latitude, where some of them are said to grow to the 
height of two hundred feet. They are occasionally 
found of a very large size ; one of them, mentioned 
by Dr. Douglas as growing on the banks of the 
river Merimac in the year 1706, being seven feet 
eight inches in diameter at the lower end. The 
wood of this pine was considered of such utility, that 
a law was made in the ninth year of Queen Anne, 
to preserve the timber, and to encourage the growth 
of the trees in America. 
Among the useful species of this genus may like- 
wise be mentioned the larch, ( Pinus Larix Linn.) 
which is a native of the Alps and Appenine moun- 
tains, but now become very common in this coun- 
try. In Switzerland the inhabitants are said to 
cover the roofs of their houses with shingles made 
O 
