22i3 BOARD OF AGRICIiLTURE. 



point, exceed 1 foot in 30, nor fall below 1 foot in 200. A straight 

 road is frequently the worst, running across bogs and up steep 

 ascents. 



When a hill comes between two points which are to be con- 

 nected by the road, then the question arises, whether the road 

 shouhr^pass around or over the hill. On level ground a deflection 

 of 100 feet from a straight line between two points 600 feet apart 

 adds only 32 feet to the length of the road. With the two points 

 one mile apart a deflection of one-fifth of a mile, or 1056 feet, in- 

 creases'the horizontal distance by only about 400 feet, which is 

 frequeiitlj'- enough for the avoidance of hills or swamps that would 

 greatly augment the cost of building the road and the after cost 

 of keeping it up. It is a fundamental law that directness of route 

 should be sacrificed to diminution of grade — to the extent always 

 of 20 feet of distance to 1 foot of elevation. Eather than climb a 

 hill 100 feet high, for example, it is at all times better to go a 

 horizontal distance of 2000 feet further around ; and it is frequent- 

 ly judicious to go 3000 feet, or 30 feet of horizontal distance to 

 save 1 foot of rise. Thus the longest way round is the shortest 

 way home, as the many experiments of scientific road-builders 

 have demonstrated. 



If, however, a hill cannot bo flanked, but must be ascended, 

 then the road should go over it in a course sufficiently zigzag to 

 keep the grade down to 1 foot in 30. Only for very short dis- 

 tances should the longitudinal slope of a road exceed this figure. 

 The great Holyhead road, running through a very mountainous 

 district in Wales, has 1 in 30 for its maximum slope, except that 

 one section has a slope of 1 in 22, and another, very short, a slope 

 of 1 in 11. Again, the Simplon road, which crosses the Alps, 

 reaching the height of one mile and a quarter above the sea, has 

 an average slope of only 1 in 22 on the Italian side and 1 in 17 on 

 the Swiss side, while there is but a single instance, when the road 

 becomes so steep as 1 in 13. As a rule the grade of a road should 

 never be so steep in any part that a horse cannot easily carry up 

 the exceptional grade the load, which it usually draws on a level. 

 While going up hill there should be no demand /or excessive 

 eflbrt, except for the briefest interval, nor any necessity for hold- 

 ing back while descending. But what a vast deal of time and 

 power is now wasted in the ascent and descent of hills traversed 

 by our country roads ! With a light carriage, the horse should 

 be able to ascend and descend the worst hills in a " round trot," 



