No. 144.] 81 



competent. A political inspector would be out of his latitude 

 upon this work— even though he would be remarkable as such 

 upon cobble-stones. 



The next point is, if possible, more important to be guarded 

 against than the others: it is the watering of the street to allay 

 the rising of the dirt, which neglecting authorities permit to ac- 

 cumulate. 



When it is desirous to wear down or polish an extremely hard 

 stone, water and sand are the most successful materials, and fric- 

 tion the most rapid power. Such is the plan adopted by the cor- 

 poration of any city, when it permits a square block pavement to 

 be watered ; for the revolving wheels will polish it as efficiently 

 in one day as would be accomplished by the same rolling power 

 in one month without the aid of water. It may be stated that 

 rain produces the same efiect — suppose it does 1 — and that effect 

 is a detrimental one : Does that advise an artificial scheme for imi 

 tation? But such is not always the effect of rain ; when it is a 

 gentle rain it is so, for then it resembles the corporation watering 

 pot, which drops just sufficient water upon the surface to com- 

 pose the dirt into a slippery paste, jeopardising thereby the limb 

 if not the life of all who have the courage to slide across its sur- 

 face. With a heavy rain the result is different : the surface of 

 the street being free from holes, the water flows rapidly over the 

 well- studied inclination to the gutters on each side, carrying with 

 it into the culverts, or receiving basins of the sewers, the dirt 

 which by the gentle rain is left to scrub and polish the face of the 

 hard trap pavement ; the rolling power or friction then acts upon 

 the bare and clean surface of the stone, doing, it is true, more 

 damage than would be done if it were dry — but infinitely less 

 than if it were dirty. 



Thus it is clearly shown, that if the best method of construct- 

 ing pavements for the carriageways of cities should be discovered, 

 there is much yet to be done. First, to follow the energetic ex- 

 ample of the ancient Romans, and carry the improvement through 

 all the principal thoroughfares of the city, as fast as the means of 



[Assembly, No. 144.] F 



