VITRIFIED BRICK AS MATERIAL FOR COUNTRY ROADS. 27 
method its melting point shall be not less than 90° C. and not greater 
than 110° C. The penetration at 0° C. of a No. 2 needle acting one 
minute under a weight of 200 grams shall be not less than 2 milli- 
meters. The penetration at 46° C. of a No. 2 needle acting five sec- 
onds under a weight of 50 grams shall not exceed 10 millimeters. 1 
When grouting, care shall be exercised to prevent the grout from 
covering and setting up over this cushion. 
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 infrequeutly 
sharp angles in the alignment or abrupt changes in the grade, which 
might be easily and inexpensively remedied by an experienced 
engineer, are ]eft 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 
expensive 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. 
1 Instead of making a poured joint,, as above described, the cushion may be constructed of some of the 
specially prepared expansion-joint materials. These consist of thin, flexible boards, built up by successive 
layers of felt and a soft bituminous material. They can be obtained with a width approximately the 
depth of a brick, and a sufficient number of them to make the proper thickness of cushion are set on edge 
along the curb when the brick are laid. 
