538 PRACTICE OF AGRICULTURE. Part III, 



be rejected which are now used j but the additional expense would be very well 

 bestowed. 



3451. In laying doivn the stones, each stone, according to Edgeworth, should bear broadly 

 and firmly on its base ; and the whole should be rammed repeatedly, to make the joints 

 close ; the upper and lower sides of the stones should be as near each other as possible, but 

 they should not touch each other laterally, except near the top and bottom, leaving a 

 hollow in the middle of their depth, to receive gravel, which will serve to hold them 

 together. This method of paving may be easily executed by common workmen, who 

 may throw iu gravel between the stones as they are laid down. It may be easily con- 

 ceived, that if a grain of gravel inserts into holes that are in stones opposite to each other, 

 they will dowel them together. It will be useful to cover a newly-made pavement with 

 gravel, which will preserve the fresh pavement for some time, from the irregular pressure 

 of wheels, till the whole is consolidated. It should be observed, that the stones should 

 be of equal hardness, or the soft ones will be worn down into hollows. In every 

 species of paving no stones should be left higher or lower than the rest ; for a wheel de- 

 scending from a higher stone will, by repeated blows, sink or break the lower stone upon 

 which it falls. 



3452. I'he requisites for laying down the stones and forming a good pavement are, 

 according to Walker, to have the stones properly squared and shaped, not as wedges, 

 but merely as rectangular prisms ; to sort them into classes according to their sizes, so as 

 to prevent unequal sinking, which is always the effect of stones, or rows of stones, of 

 unequal sizes being mixed together ; to have a foundation properly consolidated before 

 the road is begun to be paved ; to have the stones laid witli a close joint, the courses 

 being kept at right angles from the direction of the sides, and in perfectly straight lines ; 

 the joints carefully broken, that is, so that the joint between two stones in any one 

 course shall not be in a line with or opposite to a joint in any of the two courses adjoin- 

 ing. After the stones are laid they are to be well rammed, and such of the stones as 

 appear to ram loose, should be taken out and replaced by others ; after this the joints 

 are to be filled with fine gravel, and if it can be done conveniently, the stability of the 

 work will be increased by well watering at night the part that has been done during the 

 day, and ramming it over again next morning. The surface of the pavement is then to 

 be covered with an inch or so of tine gravel, that the joints may be always kept full, and 

 that the wheels may not come in contact with the stones while they are at all loose in their 

 places. Attention to these points will very much increase both the smoothness and the 

 durability of the paving. He has found great advantage from tilling up, or, as it is 

 called, grouting the joints with lime-water, which finds its way into the gravel between 

 and under the stones, and forms the whole into a solid concreted mass. The purpose 

 served by the lime might also be effectually answered by mixing a little of the borings or 

 chippings of iron or small scraps of iron hoop, with the gravel used in filling up the 

 joints of the paving. The water would very soon create an oxide of iron, and form the 

 gravel into a species of rock. He has seen a piece of rusty hoop taken from under water, 

 to which the gravel had so connected itself, for four or five inches round the hoop, as 

 not to be separated without a smart blow of a hammer ; and the cast-iron pipes which 

 are laid in moist gravel soon exhibit the same tendency. 



3453. ^s substitutes for paving stones, plates of cast iron moulded into the form of the 

 surface of a pavement of difierent sizes, (fg. 442 c, d, e), have been tried ; but on the 

 whole they are not considered as likely to succeed. They are very hot in summer and more 

 slippery than stone in winter ; but what is most against them is, that the water finds its 

 way beneath them and softens the substratum. This, at any time of the year, tends 

 directly to produce holes by the leverage of the wheels and feet of animals (3325.) ; but 

 after a severe frost the effects are ruinous. At ail events this description of pavement 

 does not appear so well adapted for the sides or middle of public roads as that of granite 

 stones prepared in Telford's manner (3450.). 



3454. Various improvements in laying pavements have recently been devised, such as 

 laying the stones dry on clay, vising square stones, or stones equally wide at bottom as 

 at top, using stones alternately wider at bottom and top, 440 



and joining them with cement {fg. 440.), paving on plates 

 of iron, wood or stone, or on a mass of masonry, &c. If 

 pavements m towns did not require to be frequently lifted 

 on account of sewers, and water and gas pipes, paving in 

 this manner on a solid foundation would certainly be the 

 best mode ; but as things are, and even probably if pavements did not require to be fre- 

 quently lifted, M' Adam's roads are found greatly preferable for all broad streets, and 

 where attention is had to keep them clean and in complete repair. In Britain at least, 

 they will probably soon supersede all common pavements, and all other description of 

 A.onunon roads. 



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