Some cities specify that the brick shall be gaged to thickness: but this is unnecessary, since even fairly good brick are practically uniform. In some cities it is required that each five or six courses of brick shall be driven up from the face by striking with a sledge against a 2" X 4" piece resting against the last course; but this is unnecessary, if each brick when laid is pressed, or rather struck, against the side of the course already in position. In any case the courses should be straight across the street; and if they are not laid so, they should be straightened by driving up each five or six courses from the face. Sometimes the bricks in a row are crowded together endwise by inserting a crow bar at the curb; but this is unnecessary provided each brick as it is laid is bumped against the end of the preceding one.
sand bed so that traffic may not depress some of the brick, which will make the pavement rough and also make it wear needlessly fast.
The pavement should first be rolled longitudinally, beginning at the crown and working toward the gutter, taking care that each return trip of the roller covers exactly the same area as the preced ing trip so that the second passage of the roller may neutralize any careening of the brick due to the first passage. Pavements that have been rolled only once or always in one direction, are. very much rougher and more noisy than when properly rolled. If a spot is skipped on the return passage of the roller, it can be de tected by a casual inspection or by the noise of a passing vehicle. The first passage of the roller shr•ild be made at a slow speed, not faster than a slow walk, to prevent undue canting of the brick. After the pavement has been rolled longitudinally, roll it back and forth transversely, or at least in 13‘ th directions at an angle of 45 degrees from curb to curb.
If the rolling is well done the &bad cushion will be pushed up between the brick I to of an inch.
A comparatively few cities specify that the brick are to be settled into the sand bed by ramming. The weight of the rammer varies from 40 to 90 pounds, usually from 75 to 90 pounds. For the form of rammer ordinarily used, see Fig. 138, page 527. The rammer is used on a 2-inch oak plank laid on the brick parallel to the curb. The proper ramming of a brick pavement is exceedingly hard work, and only a few men are strong enough to do it even fairly well.
Ramming does not tilt the brick; but it costs considerably more, can not give as even a surface, and is not likely to be thor oughly done. A few cities specify that in ramming the surface is to be trued up with a straight edge. An occasional city specifies that the brick shall be first rammed and then rolled with a heavy roller.
In certain places the roller can not be used, as for example next to the curb, or near the edge of a concrete gutter, or around man hole covers, in which cases the pavement must be thoroughly rammed.