FLUMES AND FLUMING. 3 



TYPES OF FLUMES. 



There are only two types of flumes in general use in the United 

 States at the present 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 flume. 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. 



