94 Farm Roads on Strong Soils. 



No. 6. With sifted gravel (one-third) on a paving of oolitic 

 or lias rock (two-thirds). 



£. s. d. 



Formation (as (lei&iled) 16 



Foimdation, 6 inches deep, 11 yards, at Is. Ad. per yard ; 



quarrying measured on the road 14 8 



Filling, at 1^:^., and carting 1^ miles, at Is. Id. per cuhic 



yard per mile .. .. 019 3 



Laying pavement, &c., f'Z. per square yard 4 I3 



Hammering surface regular, |cZ. per square yard .. .. 2 9 



Covering, 3 inches deep, 5^ yards, at lO^tZ. per yard .. 4 10 



Filling, carting, and spreading 9 7i 



Finishing, 2(^. per yard 1 4i 



Total cost p«r chain 3 12 7^ 



No. 7. With sifted gravel from a distance on a foundation of 

 burnt clay ballast. 



£. s. d. 



i^ormaiion (as detailed) 16 



Foundation 2i?,\TL'Ro. ^ 1 1 3^ 



Covering, 8J yards of imported gravel, say at 5s. per 

 yard, delivered at canal wharf, within I5 mile of road 2 13 



Filling, carting, and spreading, as in No. 1 12 O5 



Finishing, at 2(Z. per yard 1 4^ 



Total cost per chain 4 11 Hi 



No. 8. The foundation of roads of much traffic may be advan- 

 tageously made of concrete — of lias lime and gravel — as adopted 

 by the Romans in their military ways through France. 



The proportion of gravel to lime should be as 4 of gravel to 1 

 of lime. The concrete should be made on the bed of the road, 

 after it is prepared for the metalling. Great care should be taken 

 when the water is added that every particle of the lime is pro- 

 perly slaked and saturated. 



The layer of concrete need not be deeper than four inches, with 

 a covering of gravel of the same depth ; but the latter should be 

 put on, if possible, in two courses, the first before the concrete is 

 set hard, in order that the gravel may penetrate it. The concrete 

 then forms a matrix, from which the gravel cannot be shifted. 

 Acceptable concrete may be made with well-burnt clay ballast in 

 lieu of gravel. 



The cost of the concrete will necessarily vary with the price of 

 lime and gravel. About 5^ bushels of good lias lime will suffice 

 for three cubic yards of gravel. Assuming that the lime delivered 

 costs Id. per bushel, and the gravel 2^. 6cZ. per yard, the cost of 

 four yards will be IO5. 85c/. ; thus — 



