CATECHISM 31 



tionate cost of about 2 cents per acre per year. The Forest Service 

 also cooperates with the State in protecting public and private lands 

 outside the national-forest boundaries where natural conditions 

 make it advisable to coordinate the work of protection. 



4. Does the Federal Government aid the State in its fire-prevention 

 and forestry work? 



The Clarke-McNary law of June 7, 1924, authorizes an annual 

 appropriation to States for the prevention and suppression of forest 

 fires, distribution of planting stock to owners of farms, and for 

 assistance to farmers in managing their forest lands. Within the 

 limits of the annual Federal appropriations the Government is 

 authorized to contribute an amount equal to that appropriated by 

 the State for these purposes. The Federal allotment to California 

 under this law. for the fiscal year 1931, was $147,000. 



5. What are the main causes of forest fires? 



The fire record for California, based on a 10-year average, from 

 1920 to 1929, inclusive, shows the following causes of fires : 



Number Per cent 



Lightning 610 21. 1 



Smokers 728 25. 2 



Incendiaries 299 10. 3 



Campers 291 10. 1 



Debris burners 288 9.9 



Railroads 135 4. 6 



Lumbering operations 94 3.3 



Miscellaneous 291 10. 1 



Unknown 156 5 .4 



Total 2,892 100.0 



Man-caused fires, 78.9 per cent of total. 



6. Why are man-caused fires usually more destructive than light- 

 ning fires? 



Lightning usually strikes on the tops of ridges and starts a small 

 fire which spreads slowly, especially if the lightning storm is accom- 

 panied by rain. 



Man-caused fires most frequently start along roads, trails, and 

 streams, in canyons, or on the lower slopes of the hills, spread 

 rapidly uphill and often become conflagrations. Fires intentionally 

 set (incendiary fires) nearly always occur during periods of high- 

 fire hazard and in more or less remote localities. 



7. Do fires ever start from bottles, glass, or other freak causes? 

 Under exactly the right combination of factors, fires ma}' originate 



from freak causes, but authentic cases are so very infrequent that such 

 causes may be excluded as practical agencies of fire. 



8. Will burning cigars and cigarettes thrown from airplanes in 

 flight start fires? 



Yes. Tests made by the Forest Service have proved that fires 

 may be started in this manner. 



9. What are the natural factors that determine the rate of spread 

 of fires? 



