The Coeur d'Alene press. (Coeur d'Alene, Idaho) 1906-1907, 1906-10-08
HAS THE BIGGEST
BEARTRAP DAM
Post Falls Boasts Of This Dis
tinCtiOn

from the original beartrap to the de-
sign recognized as having unusual
merit, that of being readily proper
toned to all heights Of backwater.
Passing over some unimportant and
grotesque notifications we come to
Girard's French patent, in which the
lower leaf was hinged near the mid
die.
''This was new idea Of genuine
merit, but the French engineers fail
ed to appreciate its merits and 1t re-
manned for Thomas Parker Of Menom-
iuee, Wis, to improve upon Girard's
patent by revising the gate, pulling
the folding leaf up stream, and pro.
tecting the gate against destruction
by an upstream leaf. We're IL not for
this leaf debris would sooner or later
jam between the upper leaves and
wreck the gate. Next we note Lang's
improved gate, In which one of the
leaves of the Parker gate Is replaced
by tie and the upstream protecting
leaf shortened. Several dams Of the
Parker and Lang types Of beartrap
have been constructed la the middle
west, all OF which are giving satisfac.
tion. They find particular favor with
lumbermen in the Improvement of
streams for driving logs, and this fact
has extended their use. Next we
come to the reversed Parker, form
proposed and patented by CAPTAIN A.
.. Powell and Archibald johnson in
1906, both these gentlemen being at
that time engineers In the United
States engineer office, st. Paul. Sew
eral are in successful operation. IT
Is particularly sensitive to difference
In elevation Of head and tail water,
that installed at Lake Winnibigos-
hish dam In northern Minnesota rls
ing with head OF but two inches.
THE beartrap at Post Falls is OF
the revised Parker type, The entire
controlling works at the north chan
mel, including the beartrap, was de-
signed by the patentee of the revised
Parker beartrap. Il was completed
! just before high water this spring,
bat because Of freshly placed concrete
in the foundation no attempt was
made to operate the gate until the
foods had partly subsidized. II was
then found that the gate would not
rise, owing to the excessive weight
upon the idler or downstream leaf.
This leaf was accoroingly removed,
the location of this gate being such
that the ldler was not essential, and
since that time tho beartrap has
worked In a satisfactory manner, re-
spending perfectly TO the operation
Of the controlling valves.
Though there are several larger,
the beartFap at Post Falls Is one
of the large beartraps, and probably
the largest ever constructed Of its
type II closes an opening 10 feet
wide and In common with the work
ing Of all dams of tho beartrap type,
il opearted with ease by one person.
This Is one of the features Of this
class of gates--the ease and simpli-
city Of operation, The beartrap In
the Chicago Drainage canal spans an
opening 100 feet wide; one was built
ON the Monongahela river 100 feet
wide, and there are doubtless others
closing passes In excess Of 100 feet.
The object of the beartrap at Post
Falls Is to provide an easily oontroll-
ed opening for the passage of an inn
mense volume Of water laden with de.
bris and drift.
BY its intallator, provision has
been made TO pass without raising the
river in the least above its natural
level, all the water and more, that
ever came In the highest known wat.
J er. In other words, the beartraF
type OF movable dam, in conjunction