122 HIGHWAY CONSTRUCTION 



Quarter-Round, (Fig. 74). Made of any desired radius. Used 

 for forming corners and edges. 



Jointer (Fig. 75). Used for 

 ti-imming and finishing the joints. 



Cutter (Fig. 76). Used for cut- 

 ting the concrete into blocks. 



Gutter Tool (Fig. 77). Used 

 for forming and finishing gutters. 



Imprint Rollers (Figs. 78 and 

 79). Here are shown two designs 

 of rollers for imprinting the surface 

 of artificial stone pavements with 

 grooves, etc. 



SELECTING THE PAVEMENT 



The problem of selecting the best pavement for any particular 

 case is a local one, not only for each city, but also for each of the various 

 parts into which the city is imperceptibly divided; and it involves so 

 many elements that the nicest balancing of the relative values for each 

 kind of pavement is required, to arrive at a correct conclusion. 



In some localities, the proximity of one or more paving materials 

 determines the character of the pavement ; 

 while in other cases a careful investigation 

 may be required in order to select the 

 most suitable material. Local conditions 



i ! i ! , 'iii . Fi S- 77 - Gutter Tool. 



should always be considered; hence it is 



not possible to lay down any fixed rule as to what material makes the 



best pavement. 



The qualities essential to a good pavement may be stated as 

 follows : 



(1) It should be impervious. 



(2) It should afford good foothold for horses. 



(3) It should be hard and durable, so as to resist wear and dis- 

 integration. 



(4) It should be adapted to every grade. 



(5) It should suit every class of traffic. 



(6) It should offer the minimum resistance to traction. 



(7) It should be noiseless. 



(8) It should yield neither dust nor mud. 



