Canadian Forestry Journal, August, igi6 



677 



Brookfield double petticoat pony in- 

 sulator on 2-inch by 2^-inch oak 

 bracket at every fifth to seventh tie. 

 No. 12 B. W. B. iron wire and No. 



18 siezing strand is used for the 

 ties. In stringing a tree line a max- 

 imum amount of sag is allowed to 

 permit the wire to be borne to the 

 ground by falling trees, instead of 

 breaking. The wire must, however, 

 clear a man on horseback. 



Telephone wall sets are used 

 where the instruments are in houses, 

 while an iron set, is used where no 

 protection is available. Patrolmen 

 and repair men carry a portable set, 

 No. 1375-A developed for the United 

 States Forest Service. 



Three hundred and sixty miles 

 were erected during 1913 at an aver- 

 age cost of sixty dollars per mile; 

 ninety miles in 1914 at one hundrea 

 and twenty-five dollai '-, per mile, and 

 36.2 miles in 1915 at a cost of $26.50 

 per mile. The higher cost per uniu 

 in 1914 is due to the great expense 

 of transporting material for the up- 

 per end of the line from Revelstoke 

 to Big Bend, one hundred and twen- 

 ty-five miles, which had to be done 

 on pack horses, and the expense en- 

 tailed in purchasing and laying four 

 miles of submarine cable in the 

 Heriot Bay line. This cable is sin- 

 gle conductor seven strand No. 19 

 B. & S. copper tinned, 3/32 inch wall 



special submarine rubber tape serv- 

 ing of jute, with No. 10 B. W. G. 

 galvanized steel armo-ar. The cable 

 was required for crossing Okishol- 

 low, Nodales and Cardero channels 

 and Loughborough Inlet, the dis- 

 tances varying front twenty-eight 

 feet to six thousand feet. The shal- 

 lowest channel was four hundred 

 feet deep and the deepest about one 

 thousand feet. The cable was laid 

 from a reel on a scow, towed by one 

 of the government launches. 



The following list of lines, con- 

 structed by the forest branch, is con- 

 stantly being added to : 



Hazelton-Suskwa River, twenty 

 miles ; Terrace-Lakslse Lake, seven- 

 teen miles; Heriot Bay- Loughbor- 

 ough Inlet sixty-four miles ; Prince- 

 ton-Five Mile Creek, twenty miles ; 

 Kelowna-White Mt. Lookout Sta- 

 tion, twelve miles ; Vernon-BX Mt. 

 Lookout Station, eighteen miles ; 

 Grand Forks-North Fork Kettle 

 River, forty-four miles; Erie-Second 

 Relief Mine, fourteen miles; Arrow 

 Park-Mosquito Creek, seven miles; 

 Lardo-Duncan River, forty miles ; 

 Revelstoke-Big Bend, one hundred 

 and twenty miles ; Creston-Goat Mt. 

 Lookout Station, three miles ; Cran- 

 brook-Baker Mt. Lookout Station, 

 seven miles; Canal Flats-Upper 

 Kootenay River, twenty miles, and 

 Natal-Upper Elk River, forty-five 

 miles. 



Prof, 5. B. Green on ''Causes of Fires" 



The following was written by 

 Prof. S. B. Green in "Forestry in 

 Minnesota" and has an interesting 

 relation to the conditions giving rise 

 to Canadian forest fires : 



"Spring fires are very injurious to 

 trees and especially tender seed- 

 lings for trees in the spring of the 

 year are full of sap and can endure 

 but little heat. 



Summer and Autumn fires gen- 

 erally run deep into the ground and 



if the soil is very dry and of a peaty 

 nature burn ofif the roots of the 

 trees. The result of this is that the 

 trees are blown down in great con- 

 fusion and form what are known as 

 "fire falls." Where a thick growth 

 falls, it forms an almost impassable 

 barrier which remains in this state 

 until decay and repeated fires ex- 

 tending over a long series of years 

 finally destroy the trees and perhaps 

 get the land into condition for a new 

 growth. 



