STATE GEOLOGIST. 201 
The specifications in use in Columbus, Ohio, are as follows: 
SPECIFICATIONS FOR IMPROVING SIDEWALKS WITH ARTIFICIAL STONE, IN THE 
CITY, OF COLUMBUS, OHIO. 
1. By “artificial stone’ herein specified is meant a composition of Port- 
land cement, sand, and tragments of natural stone. 
2. By “sub-grade”’ is meant the ground surface upon which the pavement 
foundation is laid. 
3. By “sub-drainage” is meant a line of three (8) inch diameter, round, 
butt-jointed, hard-burned drain tile, laid in a trench one foot wide and one 
foot deep below sub-grade, parallel to the direction of the sidewalk, and true 
for line and grade, the trench to be filled to the sub-grade with broken stone, 
crushed or screened gravel as herein specified for concrete, which shall be 
compacted by ramming, care being used not to disturb the drain tile. The 
out-let or discharge for the drain to be by connection with the street inlets, 
or, in the absence of street inlets, by such other arrangement as the Engi- 
neer may prescribe. 
4, By “cinders” is meant clean, sharp, soft coal cinders, free from ashes 
and clinkers. 
_ 5. By “screemed gravel” is meant clean sharp bank gravel, free from 
loam or vegetable matter, so screened that no fragment will measure more 
CIDA TIRIN Onter gs vee Sis ahd inches on its longest diameter, and not enough of these 
to make the quantity of fine gravel so small as to prevent its packing readily 
under the roller. The question as to whether the material is too fine or too 
coarse, and as to its general suitableness for the purpose for which it is 
intended, shall rest entirely with the engineer. 
6. By “sand” is meant clean, sharp bank sand, free from loam, vegetable 
matter, or fragments of coal, and screened free from pebbles. 
7. By “broken stone” is meant granite, trap-rock, hard limestone, or 
other hard durable stone, so broken or crushed that no fragment will measure 
more than one and one-half (114) inches on its longest diameter, nor less 
than one-half (14) inch on its shortest diameter, to be entirely free from 
dust or dirt. 
8. By “cement” is meant German or American Portland Cement. The 
cement to be received on the work in unbroken packages, to be fresh, free 
from lumps, and subject to inspection by the Engineer in every case. 
9. By “crushed gravel” is meant clean sharp bank gravel, free from . 
loam or vegetable matter, so broken or crushed that no fragment will 
measuring more than one and one-half (1144) inches on its longest diameter. 
10. By “paving” is meant the laying of an artificial stone pavement 
where the sidewalk has not been previously paved with artificial stone. 
11. By “repairing” is meant restoring in part artificial stone sidewalks 
previously laid. 
PAVING. 
Sub-grade,—The sub-grade will be brought to an even compact surface 
uniformly twelve (12) inches below the proposed surface of the finished 
pavement. Soft or spongy earth, vegetable or other perishable matter will 
be removed, and the space filled with gravel or broken stone thoroughly com- 
pacted by ramming. 
Sub-drainage. —Sub-drainage will be put in where the Engineer directs. 
Foundation, Upon the sub-grade thus prepared will be spread a bed of 
cinders, crushed or screened gravel, in sufficient quantity to insure a uniform 
