S h .
i n l a n d n a v i g a t i o n . 489
pines, rife in the mid it o f the itream, forming- finall ftraits, c h -a p .
down which the water daihes with increafingimpetuofity.
From the firft opening o f the fall to the part where the
river again becomes navigable is about two miles ; but it doe's
not rdll. through the whole of this fpace in one uniform iheet
of water, or with equal rage and violence. It is divided into
four principal cataradts, each whereof is feparatetl by whirlpools
and eddies, .forming,- during the whole Way, the moft
awful fcenes, ever varying, and too fublime to be accurately
defcribed. The perpendicular height o f all the falls, confi-
dered as one, is about 100 feet.
From this defcription the reader will readily conceive the
extreme difficulty o f rendering^ theie cataradts navigable ;
and yet.it was even through the midft o f them that the daring
projector attempted to form a canal, by the following
works, which are marked in the annexed plan.
Juft above .the firft cataradt, called PraiiénkeTdet Fall, federal
dams were conftrudted, which turned the ftream, and
left the main bed o f the river quite dry. In this part fome
rocky lflands were cut through, or blown up ; the bed was
rendered level, and the cataradt nearly turned into itill water.
To continue the navigation, an iiland o f red granite, called
Malg, which rifes in the midft o f the great cataradt, was
divided, and a canal formed throùgh it o f 340 feet in length
incl uding a 11 nice o f 3 0 : the depth o f the fall, and, o f courfe[
the depth o f the perforated rock, is g £ g j feet; the breadth
18. This is called Ekerbrad fluice, and was defigned to
confift o f two -locks. At a fmall diftance another cabal was
formed on the fide of the fécond great cataradt, through a
kind of promontory which projedts into thé ftream ;• the
folid granite was hollowed 860 feet in length, 56- in depth
and 18 in breadth. This fluice, called Polheim’s fluice, wal
V o l. II. JR r r t0