596 

 369] 



PRACTICE OF AGRICULTURE. 



Pai^tiIJ. 



548 



Telford, in filling broken stones, and also in scattering them on the road, makes 

 use of a pronged shovel, fourteen inches square, 

 which may be universally recommended for this 

 purpose (jig. 548. d). His large hammer (o), 

 small one (6), and gauge for the size of the broken 

 stone (c), are in very general use, as w^ell as 

 the pronged shovel. Hammers may be made 

 of cast iron, where the stones to be broken are 

 about their own weight ; the best shape is a 

 narrow oval : the advantage of using cast iron 

 is its cheapness. {Farm. Mag. xxii. 159.) 



3692. Telford's level, for adjusting the de- 

 clivity of roads from the middle to the sides 

 {Jig. 549.), is also a very complete implement 

 of the kind. 



3693. T'he mode of depositiiig materials by Paterson is as follows : " Bottom 

 metals should be broken on the road. When they are thus broken, they are, by the 

 force of the hammer, finnly bedded into the bottom, and are so closely and compactly 

 beaten together, that they become like pavement. In this state they are not only 

 less liable to sink, but they form a much better bed for the top metals than when they 

 are thrown loosely on. And besides this, when they are put on in a loose manner, 

 as is frequently done, the mud more readily works up through the metals in time 

 of rains, and makes a disagreeable road : the top metals also are easily beaten down, 

 by the horses' feet and the carriages, through the bottom stones, when loose and 

 open ; so that the small metals frequently get undermost, and the large ones make 

 their appearance at the surface, very much to the injury of the road. Taking all these 

 circumstances, therefore, into consideration, it is of the greatest importance that the 

 bottom metals should not only be much larger in size, but that they also be broken on 

 the road." This may be considered as at variance with several parts of Paterson's second 

 publication. Letters, <^c. The road being drained and prepared for the materials, he 

 then directs (p. 80.) to put them on in the following manner: " M' Adam's mode of 

 putting them on, in coats of three or four inches, though good in particular instances, 

 will not do as a universal rule. If the bottom is wet, and the weather rainy, the earth 

 will poach and work up through the materials, in spite of all the attention and care that 

 can be bestowed. I would, therefore, recommend in such cases to put on the first 

 course from five to six inches thick. But then to leave these materials to consolidate, 

 or rather to move and shift about by the wheels ; and then to be levelled by the rakes, 

 alternately, according to M' Adam's plan, wears away the corners of the stones, by which 

 means they do not unite together and make such a firm road. There were upwards of 

 two miles of road made under my directions lately, on which I caused a course of about 

 six inches to be put. But before opening it to the public, I got a heavy stone roller to 

 ply upon it for four days. This beat and firmed the materials so much, that the wheels 

 of the carriages made little impression upon it. Of course the materials retained their 

 angular points more than in rolling and shifting by every carriage- wheel that passed ; 

 and there was less labour in raking and levelling the road. This plan, which carries reason 

 on the face of it, I would strongly recommend. As to M' Adam's plan of putting on the 

 materials in shovelfuls, it is certainly good. I used to prohibit putting them on with 

 carts (as in that case you never have the small and the great properly mixed together), 

 and generally put them on vnth wheelbarrows : but even this does not mix them quite 

 so well as scattering them with the shovel ; and as it is of considerable importance to 

 nave them well mixed, I would by all means recommend the mode best calculated for 

 that purpose." 



3694. Rolling newly laid on metals is generally approved of. The roller used should 

 not be less than four or five feet in diameter ; a smaller size, especially in the use of 

 gravel, being apt to drag and force the loose materials before it. Some have attempted 

 to keep roads in order by occasionally harrowing and then rolling them ; but the best 



