22 



IOWA DEPARTMENT OF AGRICULTURE. 



lines. This would often take much more of one farm than another, but 

 the inequality of burden could be adjusted by a money payment for the 

 excess. 



'MSAfrS'.UiA; 



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Fig. 1.— The road from Knoxville to the Experiment Station farm formerly went up one 

 steep hill A Y, and. down another, Y Z. The relocated road, A to C, is comparatively 

 level and much shorter. 



In the prairie State of Iowa, for example, where roads are not as 

 steep as in many other states, there is a greater number of roads having 

 steep grades, and on an average the grades are steeper, than are found 

 in the mountainous republic of Switzerland. A great saving could be 

 effected by relocating many of them. 



In Maryland the old stage coach road running from Washington to 

 Baltimore nyakes almost a "bee line," regardless of hills or valleys. The 

 grades in places are as steep as 10 or 12 per cent,*where by skirting the 

 hills the road might have been made almost level, or by running it less 

 abruptly up the hills which had to be ascended the grades might have 

 been reduced to 3 or 4 per cent. 



DISADVANTAGES OF HEAVY GRADE. 



Straight roads are best, other things being equal, but in hilly coun- 

 tries straightness should always be sacrificed to reduce grades. Hilly 

 roads often become covered with ice or slippery soil, making them very 

 difficult to ascend with loaded vehicles, as well as dangerous to descend. 

 Water rushes down them during rainy weather at such a rate as to wash 



♦Per cent of grade means so many feet up, vertically, in 100 feet horizontal. A 10 per 

 cent grade, for instance, means a rise of 10 feet for each 100 feet of horizontal distance 

 traveled. There being 5, 280 feet in a mile a 1 per cent grade means a rise of 52. 8 feet in 

 that distance. A 10 per cent grade means a rise of 528 feet, and a 12 per cent grade means 

 a rise of 634.6 feet to the mile. 



