32 BULLETIN 373, U. S. DEPARTMENT OF AGRICULTURE. 
course, and the joints between the ends of the brick shall not exceed one-eighth 
(i) inch in width. Joints shall be broken by starting each alternate course 
with a half brick. Nothing but whole brick shall be used, excepting the half 
brick for starting alternate courses and pieces of brick for closures, and no 
piece of brick less than two (2) inches in length shall be used for making a 
closure. The cutting and trimming of brick shall be done by experienced men, 
and proper care shall be taken not to check or fracture the part to be used, and 
the ends of the part used shall be square with its top and sides. 
The brick shall be carried to the bricklayers on pallets or in clamps and not 
wheeled in barrows. The bricklayers laying the brick shall stand on the brick 
already laid and shall not in any manner disturb the bedding. Xo heavy driv- 
ing will be permitted to straighten courses, and in making closures the pieces 
of brick shall be so cut that they may be laid in place without driving. Brick 
shall be laid wirh the best edge up. Batting for closures shall progress with 
the laying. 
After the brick are laid they will be carefully inspected, and all those which 
are soft, cracked, glazed, spalled, overturned, or otherwise imperfect will be 
marked by the inspector. The contractor shall at once remove such brick from 
the pavement wirh fiat-nosed tongs, without disturbing the bedding, and shall 
replace them with approved brick. Kiln-marked and slightly chipped brick, 
if not otherwise defective, may be turned over and, if the reverse edge is 
smooth, may remain in the pavement. 
If more than one kind of brick or the brick from more than one plant is fur- 
nished for the work, each particular kind or make shall be laid in a separate 
section. 
Rotting brick. — After the brick have been laid and after all objectionable 
brick have been removed from the pavement they shall be brought to a true sur- 
face by means of rolling. The rolling shall be done with a motor or steam 
tandem roller weighing not less than three (3) and not more than five (5) 
tons. The pavement shall be rolled in longitudinal and diagonal directions. 
The longitudinal rolling shall begin at the curbs and progress toward the center 
of the pavement. The pavement shall then be thoroughly rolled diagonally at 
an angle of forty-five (45) degrees with the curb. When this rolling has been 
completed the brick will again be inspected, and all that are broken or dam- 
aged shall be removed from the pavement and replaced with approved brick. 
If necessary to secure a uniform surface the brick shall then be again rolled. 
the roller moving diagonally across the pavement at right angles to the first 
diagonal rolling. To prevent the brick from being left careened the roller 
shall in all cases cover exactly the same area in making its backward trip as 
was covered in its forward trip, and shall proceed at a very slow rate of 
speed until the entire pavement has received the first rolling. In no event 
shall the rolling be clone when the bedding is in a condition such that the sand 
or dry mortar will flow up into the joints more than three-eighths (f ) inch. 
Filling the joints. — After the brick have been rolled as above specified the 
joints between them shall be filled with a grout containing equal parts of cement 
and sand. The grout shall be mixed in a mechanical batch mixer or by hand in 
batches containing not more than one sack of cement. Hand mixing shall be 
done in a box about five (5) feet long, thirty (30) inches wide, and fourteen 
(14) inches deep, resting on legs of different lengths, so that the mixture 
will readily flow to the lowest corner of the box. The sand and cement shall 
be thoroughly mixed dry. Sufficient clean water shall then be admixed to 
produce a grout of a consistency about equal to that of ordinary cream for 
the first application and of a slightly thicker consistency for subsequent applica- 
tions. From the time the water is added to the mixture until all of the 
