BEICK EOADS. 25 
of the amounts of wear sustained by given pavements during com- 
paratively long periods of years have not been sufficient to warrant 
any very definite conclusions as to the probable terms of service, 
though they indicate that good paving brick wear very slowly under 
ordinary traffic. It is evident that in order to secure the full benefit 
of this excellent resistance to wear the surface of the pavement must 
not be permitted to become uneven because of the failure of a brick 
here and there. 
CONCLUSION. 
Before concluding this discussion of brick pavements, it would 
seem desirable to emphasize the importance of proper engineering 
supervision. In the past many communities have expended large 
sums in efforts to improve their public highways without first having 
secured the services of some one competent to plan and direct the 
work. The results have usually been very unsatisfactory under such 
circumstances and have frequently served to discourage further 
effort. One of the mistakes most commonly observed consists in 
constructing some expensive type of pavement on a road where the 
location is faulty or the grades are impracticable. Not infrequently 
sharp angles in the alignment or abrupt changes in the grade, 
which might be easily and inexpensively remedied by an experienced 
engineer, are left to impede traffic throughout the life of a costly 
and perhaps durable pavement. 
Even in constructing common earth roads it is doubtful economy 
to dispense with the services of a competent engineer, and if any 
considerable quantity of work is to be done, such services should 
certainly be secured. Since brick pavements are probably more ex- 
pensive to construct than any other type of pavement at present 
used for country roads, it is all the more important that their con- 
struction should be carefully planned and well executed. 
