The Via graph. 45 



a 30 mile journey on such a road has in effect to climb a hill 

 (over and above any recognised hills on the road), which is 

 greater in height than Slieve Donard, and is made up of ruts 

 alone. A simple calculation shows that if we consider a vehicle 

 weighing with its load one ton, and travelling at 7 miles per 

 hour, the extra power required to take it over these ruts is 

 just over \ horse power ; or, if we take as an example of 

 heavy traffic a weight of 35 cwt., at 3| miles per hour, the extra 

 power required is just under | horse-power. The same 

 calculation, applied to the Liverpool and Prescot road gives 

 about 5' horse-power in each case. A comparison therefore 

 shows that the ruts on the Lisburn road entail either the use 

 of about half as many more horses than are really needed on 

 a good road, or a loss to an equivalent amount in speed or in 

 weight carried. 



The instrument here shown, was constructed to my design, 

 by Mr. Alexander Gass, of College Street South, and is a very 

 creditable example of finely-executed work. The name of the 

 workman chiefly employed on it, Alexander Cook, ought also 

 to be mentioned as having taken great pains in carrying out 

 the details. 



The records of the instrument would be of use to those 

 criticising the state of the roads in any district, also to surveyors 

 wishing to test various methods of road maintenance or to 

 convince their county authorities of the need of improvement 

 or of the advantages already obtained by a given treatment. 

 They would also be valuable to cyclists and others desirous of 

 knowing the condition of the roads in any distant district in 

 which they proposed to travel. 



Having shown that our Irish roads compare so unfavour- 

 ably with those across the Channel, it may be asked 

 why, and how can they be improved. Not being an expert in 

 road management, I feel diffident about saying much on this 

 question. T would point out, however, that Macadam, the 

 father of the modern English road, insisted chiefly on three 

 points — first, thorough drying of the road-bed by underground 



