AMERICAN INSTITUTE. 627 



ter between tliem; but in course of time these stones become 

 rounded like cobble stones, which form the worst of pavements. 

 Iron seems to be the only material which can be used to secure 

 all the requisites alluded to. Several kinds of iron pavements 

 have been invented, but none introduced as yet seem to fulfil all 

 the required conditions. I believe a perfect kind of pavement has 

 been made of iron, and I hope to demonstrate its practicability in 

 this city within a few months." 



Mr. Fisher was requested to give his views on roadways, and 

 he explained fully the effect of travel on various roads, from those 

 of earth only to plates of iron. He showed that small square 

 blocks, however hard as flint, (like our Belgian pavement,) soon 

 become by wear as round on their upper side as our cobble stones 

 are naturally. That the more smooth the surface the less is the 

 traction power required; that a horse or a wheel, by their gravity 

 adhere to level and smooth surface with a power usually of about 

 33 per cent of their weight. 



That when railroads were first proposed the objection was very 

 generally made that the wheels of iron would slip on iron rails, 

 and could not ascend even a moderate grade-, but would require 

 some contrivance to aid the ascent. Iron legs were proposed to 

 take the ground and propel the engine upwards and stay its des- 

 cent. Practice has long since demonstrated the error of that 

 idea. Smooth wheels ascend considerably high grades with heavy 

 trains easily. But if there should be a difficulty for the horse's 

 foot on perfectly smooth plates, then it is perfectly easy to cast 

 the plates with such crevices for the horse's corks as are wanted, 

 and moreover there is no difficulty in laying smooth plates for the 

 wheel tracks while the horse path is creviced. But the time is 

 not far distant when the horse will not be wanted in our city for 

 passengers use — machinery far better will be applied. And with 

 iron pavement we shall be relieved from the dirt, dust and mud, 

 because the abrasion of iron makes neither, while that of the 

 stones makes much — more by far than is apparent at first view. 



Mr. Tillman was not satisfied with this iron pavement. 



Mr. Sibley had observed the great difficulty of traction by 

 horses on plates of iron at large iron works in Wales; that often 

 the horse could scarcely stand on his feet. He was utterly 

 opposed to such roads. 



Mr. Meigs adverted to the ancient condition of our roads. In 

 1805, he left Courtland street in a special coach and four horses 

 at 9 o'clock a. m., for Philadelphia, detained by stormy weather 

 an hour and an half at the ferry — six inside passengers. The 



