1012] on Thp Road: Past. Prpmit and Fufuro. ?,39 



to R!iy Tiinch about the foundation of the road. Telford insisted on 

 a foundation of large stones packed together. Macadam did not 

 consider this to be necessary, and he proved to be right. In the 

 past the road surveyor has recognized what the lower part of the 

 road which is to carry the crust should be, and it need not detain us. 

 But the question " What shall be the weight-bearing crust ? " is one 

 of vast importance, and this is engaging the attention of the advisers 

 to the Road Board. I do not intend to dogmatize on the subject, 

 but only to show you what steps of progress are being made — what 

 has already been consummated in the production of roads which are 

 to the old water-bound macadam what the genuine macadam was to 

 the old track of foot deep mud and bulky stones, which before 

 Macadam's day led to much strong language, of which I have given 

 you some specimens, also to the untimely destruction of many a 

 horse and vehicle, and enormous commercial waste of time and 

 material. One thing is now universally recognized, that the road 

 of the future shall be a truly bound road, in which, whatever kind 

 of stone is used — a matter into which there is not time to enter — 

 that stone shall be held together by some pitchy or bituminous 

 material, so that it shall be indeed a crust and not something which 

 has no real cohesion, and into which Macadam's enemy, the water, 

 can make its way whenever water falls. That this result has been 

 attained in a practical way is manifest from the pieces of road crust 

 cut out after they have been under traffic for long periods, and which 

 I now show you. (Specimens exhibited). You will see, if you care 

 to examine them afterwards, that the stones are in their places as 

 they were laid down with their plastic binding, that no water has 

 penetrated and that no stones have been picked out or forced out by 

 the traffic, and that the stones have been held so that they have kept 

 their angularity, and therefore do not tend to come out of the road. 

 Experience tends to show that such a road will remain sound, and 

 that for even twice the period that is possible in the case of a mud- 

 water bound road. That you may see how cohesive such a road is 

 Colonel Crompton, our engineer, has prepared for me these speci- 

 mens of road, showing how they will hang as a solid piece even with 

 weight attached, which of course would be impossible with water- 

 bound material. It could not be held up at all, but would fall to 

 pieces in the very act of taking it out of the road. (Specimens shown.) 



Roads formed as regards the crust in this way are now common. 

 Many can be seen in Kent and other counties near London, and 

 stretches are being laid throughout the kingdom. Great success 

 was attained by many surveyors, and notably at an early date by 

 Mr. Hooley, of Nottingham, in putting together road crusts with the 

 aid of tarry components substituted for mud binding. But there is 

 reason for thinking that possibly it is unnecessary, and indeed disad- 

 vantageous, to use any stones of size — even of Macadam's 1^-inch — in 

 making the] crust. Experiment is tending to show that suitable 



Vol. XX. (No. 106) 2 a 



