Archimedes Texts

94
more than it did at the level AF, it would rise yet more above
the said level A F; although that the self same quantity of water
runneth all the while. By the above-named solid Principle I
resolve extravagant Problems in my Treatise, and assign the Rea
sons of admirable effects of Running Waters: But as for what
concerneth our purpose of the Pontine Fenns, we have the Cau
ses very plain and clear; for which, by the trampling of Cattle
which pass thorow the Draining River, the waters abate so nota
bly, that it is as it were a miracle for those Reeds, Flags, and
Weeds that spring up, encrease, and spread all over the River,
stop and impede that velocity of the waters which they would
have by means of their declivity. But that passage of those Beasts,
treading down those Weeds unto the bottom of the River, in such
sort, as that they no longer hinder the Current of the Water;
and the same Waters increasing in their course, they do dimi
nish in measure and height; and by this meanes the Ditches of the
Plains empty into the same successfully, and leave them free
from Waters, and Drained. But these Weeds in a short
time sprouting up anew, and raising their stalkes thorow the
body of the Waters, they reduce things to the same evil
state, as before, retarding the velocity of the Water, ma
king it to increase in height, and perhaps do occasion grea
ter mischiefs; seeing that those many knots which each plant
shoots forth, begets a greater multitude of Stalks, which much
more incumbering the Water of the River, are a greater impe
diment unto its velocity, and consequently make the height
of the waters to encrease so much the more, and do more mischief
than before.

Another head to which these harms may be reduced, but pro
ceeding from the same Root, which hath a great part in this
disorder, is the impediment of those Wears in the River which
are made by heightning the bed of the same, for placing of fish
ing-nets; of which Piscaries I reckoned above ten, when I made
a voyage thorow those waters to Sandolo. And these Fishing
Wears are such impediments, that some one of them makes the
water of the River in the upper part to rise half a Palm, and
sometimes a whole Palm, and more; so that when they are all
gathered together, these impediments amount to more than seven,
or possibly than eight Palms.

There concurreth for a third most Potent Cause of the waters
continuing high in the evacuating, or Draining Chanel, and con
sequently on the Plains; The great abundance of water that issu
eth from Fiume Sisto, the waters of which do not keep within its
Banks when they are abundant; but encreasing above its Chanel,
they unite with those of the Evacuator, and dispersing thorow