FLUMES AND FLUMING. 6 
TYPES OF FLUMES. 
There are only two types of flumes in general use in the United 
States at the presert time — 
(1) The box or square upright-sided flume. 
(2) The V-shaped flume. 
The square flume is usually constructed along the general lines of 
the well-known mill flume or artificial conduit used to convey water 
from the mill pond to the mill for water power or other purposes, but 
with this difference, that the uprights on the sides of the square or 
box timber flume are rarely braced across the top of the flume, but 
instead the top of the flume is left open to afford free passage for logs, 
wood, or lumber, and the sides are. held in place by uprights fastened 
on the sills or crosspieces on which the bottom of the flume rests, and 
braced from the outside. (See fig. 1.) 
This is the oldest type of wooden flume in use, and is employed to 
some extent at the present time where economy in the use of water is 
not of any particular importance. However, the square flume requires 
more water to operate successfully with the same class of material, 
and, generally speaking, requires more lumber for construction than 
does the V-shaped flame. Furthermore, the material being handled 
is more apt to "jam" (especially the short material) in the square- 
box type. Owing to the form of its construction there are more 
joints in this type that are liable to open up and cause "leakage," in 
case the flume is allowed to stand without water running in it for any 
length of time, and except where it is desired to combine in one flume 
the two objects of carrying a large amount of water to be used for 
some purpose other than fluming below and at the same time to use 
the flume for the transportation of lumber or timber, it is generally 
more advisable to use the type of flume which requires the least 
amount of water and the least average amount of repair. Up to the 
present that is the V-shaped wooden flume, but it is perhaps not a 
flight of fancy to predict that it is only a question of time when 
strong and light " sectional" metal flumes, semicircular in form, that 
can be quickly taken apart and transported from one point to another 
and put together and set up again, will be in common use. Metal 
semicircular conduits, made in sections and easily put together, have 
already been used in hydroelectric and irrigation projects. 
There is a conduit of this character in operation on the Sierra Na- 
tional Forest in California, and the writer sees no reason why a similar 
type of metal conduit, lighter in construction and somewhat modified 
in form, could not be developed for log or lumber flumes. The initial 
cost of construction would, of course, be considerably greater than for 
a wooden flume, but the metal one would have much greater dura- 
bility and length of service. 
