L E T T E R XIX.
Reflections on the injudicious method laid down in the Spanifh ordinances,
fo r the propagation o f timber, being the fubflance o f a memorial pre-
fented by Don Guillermo Bowles, to his Excellency Don Julian de Arriaga,
Minifter o f State fo r the department o f the Indies and'Marine-
'T 'O judge of the quality o f oak, fit for building',
the four following circumftances are to be confi-
dered ; Firft, the fituation; fecondly, the nature and
depth o f the fo i lth i rd ly , the age of the tree, when it
is felled ; fourthly, the manner of laying i t down to dry-
In mountainous countries, the bell timber is, from
about midway, up to the tops of the mountains.; its
goodnefs rather decreafes, in proportion as it approaches
towards the valley.; In the lower parts, the trees grow
quicker, and are more lightly %. but as the roots mull,
always partake of a greater ihare o f moifture, from their
fituation, which expofes them to the continual flow of
water from the heights, the item is not fo vigorous nor
folid ; thus a tree on the top of the mountain, will not
be fo large nor beautiful at fixty years of age, as .another
in the valley at forty ; but let the builder be cautious
tious how he trulls to outward appearances, otherwife
he will certainly be difappointed,
It appears from various judicious experiments, that-
oaks arrive at their greateft perfection, at the period of
fifty years, when, the foil has above two feet depth, and
at feventy-five years, when the depth exceeds three and
a half; if it is above four feet, they then inereafe in vigour
arid ftrength for upwards of a century. From
whence it is evident, that trees, like animals, have their
period of youth, maturity, and decay. When they ceafe
to grow, they are come to maturity, the conduClory vef-
fels are obftrufted, the tubes turn to folid timber, the
fap ceafing to circulate, becomes all fpine or heart, and
the tree remains in a Hate o f perfection, and reft, for a
term of twenty or thirty years. This is the proper time,
between adolefcence and old age, to fell the tree ; i f it
was attempted: while the fap was yet in circulation, the
timber would be liable to warp in hot weather, be-
fides many other defecfts. We muft not imagine, that
though this operation was performed in the winter, oi
what might be thought a proper feafon, fuch as the
Spaniards call a good moon, according to the opinion
of the antients («), that thefe inconveniencies would be
(a) The ancients had a great regard to the age o f the moon in the felling of their timber.
Pliny orders it to be in the very article of the change, which happening on the laft day o f '
the winter folftice, the timber, fays he, will be immortal.
Z 2 removed.