H.A.EVELETH 



THE details of the fire-patrol system, 

 employed in the National Forests 

 under the supervision of the Department 

 of Forestry, are disclosed in an interest- 

 ing exhibit in the Palace of Agriculture. 

 The paramount feature is a reproduction 

 of one of the fire-lookout structures with 

 the customary equipment of signalling 

 apparatus. These observation towers are 

 located on the higher mountain peaks 

 where an unobstructed view may be had 

 of the surrounding country, one or more 

 of the other towers and if possible the 

 office of the supervisor; the last named 

 being the central station and headquar- 

 ters of the system. The different stations 

 or look-out towers and supervisor's head- 

 quarters are inter-connected by telephone 

 and thus the presence of a fire in the 

 forest may be brought to the attention 

 of the latter in a minimum of time. The 

 essential piece of apparatus on the ob- 

 servation platform is the fire locator, 

 which consists of a map of the sur- 

 rounding country, an alidade and a pro- 

 tractor. The alidade consists of a metal 



bar 'bent so that it forms three sides of 

 a rectangle, the longest side, about twen- 

 ty inches in length, serving as a base for 

 the instrument, while the two shorter 

 sides stand upright from the base and 

 serve as a means for its orientation; 

 the one having a narrow vertical slit 

 and the other a wider vertical slit along 

 the center of which is stretched a verti- 

 cal wire. The base is pivoted, near the 

 end bearing the narrow slit, at the cen- 

 ter of the map. In use, the alidade is 

 oriented until the eye of the observer, 

 the rear slit, the vertical wire and the 

 smoke from the fire are in line. The 

 angle between this position and a pre- 

 determined base line is then read and 

 telephoned to the supervisor. In the 

 meantime a similar process has been 

 going on at one or more of the other 

 look-out stations and the observed angles 

 are telephoned to the supervisor. Here 

 is located a map similar to that used 

 by the lookout men and, knowing the 

 position of the lookout stations and any 

 two of the observed angles, the location 



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