6 td el a 
STATE GEOLOGIST. 203 
cinder foundation will be five (5) inches thick, the concrete five (5) inches | 
thick, and the top surface two (2 inches thick. 
Repairing. —In repairing, such portions of the existing artificial pavement 
as ordered by the Engineer shall be removed and new work substituted, 
laid in precisely the same manner as herein specified under “Paving”’. 
Sidewalk Gutters or Cross Drains, —Only upon special permission by the 
Engineer will sidewalk gutters or cross drains be allowed. 
When surface drains are permitted they will be formed in the artificial 
stone pavement of such width, depth, and shape as the Engineer specially 
directs. 
Where cross-drains are permitted below the surface they will be laid 
with vitrified stoneware socket pipe, of such bore as the Dee directs, with 
joints cemented with mortar before specified. 
All openings in the curbing for outlets into the gutter for cross-drains 
will be skillfully made by a competent stone cutter, under the direction of the 
Engineer, and any curbstone defaced or broken in this operation will be 
replaced. 
CEMENT. 
Portland Cement must satisfy the following requirements: 
1. The cement shall stand a minimum tensile strain of 400 pounds to 
cne square inch section (neat briquettes 1 day in air and 6 days in water.) 
2. The cement shall stand a minimum tensile strain of 125 lbs. to one 
square inch section, 3 parts sand to 1 cement, (1 day in air 6 days in water.> 
Natural Cements must stand the following tests: 
Neat briquettes must develop after seven days a tensile strain of 100 
Ibs. per sq. in., 4 weeks 150 lbs. Briquettes made of one part cement and one 
part sand must stand at the end of seven days a tensile strain of 50 lbs. per 
sq. in., at the end of 4 weeks 80 lbs. per sq.in. 
