AGRTCULTUKAL EKGIl^EERTNG. 



185 



IMPORTANCE OF GOOD ROADS. 



It is estimated that it costs a farmer more to haul a bushel of 

 wheat than it does a railroad to haul a ton ; that our poor roads 

 cost the farmer at least $15.00 a year for every horse, and that 

 good earth roads would save more than half the cost of hauling, 

 and good permanent roads more than three quarters of it. 



(GiLMORB.) 



Force Required to Dratu a Load on Different Kinds of Roads. 



Earth road 



Gravel " 



Macadam road . . . 

 Telford " ... 

 Plank " ... 



Stone trackway.. 



Force 



Required to 



Draw a Gross 



Load of 

 2240 Pounds. 



Pounds 

 200 



65 

 46 



12j 



Steepest 

 Grade (rise 

 per 100 ft.) 



on which 

 Vehicle will 



not Roll 

 Back. 



Feet 

 8.9 

 6.4 

 2.9 



Draught on a Level Com- 

 pared with that on Dif- 

 ferent Grades. Rise in 

 feet per 100 feet. 



15 



2.7 



3-3 

 6.1 

 8.2 

 9.1 

 27.5 



TRACTIVE FORCE REQUIRED I OR CARRIAGES 



of one ton, on a level road. (McConnell.) 



Force of Trac- 

 Description of Road. tion per Ton. 



1. On rails 8 lbs. 



2. Well-made pavement 33 " 



3. Macadamized road 44 to 67 " 



4. Turnpike, hard and dry ... 6S " 



5. " dirty 88" 



6. Hard compact loam iig " 



7. Gravel 150 " 



8. Sandy and gravelly 210 " 



9. Ordinary by-road 237 " 



10. Turnpike, newly-gravelled 320 " 



11. Loose sandy road 457 ** 



A horse produces his greatest mechanical effect in drawing a 

 load 2^ miles per hour with a tractive force of 150 lbs. 



