Granite. - Granite curbing shall be of the best quality of granite, gneiss, or syenite, of uniform grain and texture, free from excess of mica, and showing an even distribution of constituent materials.

Samples. - Before accepting the material from any quarry, the operator thereof shall file in the office of the Engineer a representative sample of the curbing proposed to be furnished. This sample shall be twelve (12) inches long, of the quality, dimensions and dressing specified and must be labeled with the name of the operator and the name and location of the quarry or quarries. If this sample is acceptable, all curbing furnished must be substantially equal to it in all respects. The bidder must state in his proposal the name and location of the quarry or quarries from which he proposes to obtain his curbing. No change of quarry or quarries will be permitted without the consent of the Engineer.

Dimensions and Dressing. - The minimum length of curbing shall be five (5) feet except for closures, or for curved corners, where the length will be as ordered. The bottom length shall be not less than nine-tenths of the top length. The depth of the curbing will be sixteen (16) inches with an allowable variation of not over one (1) inch either way. The curbing shall be uniformly five (5) inches thick on top between neat lines; elsewhere the thickness shall be not less than four (4) nor more than seven (7) inches at any point. The base of the curb must be at right angles to the face and must be of the full required thickness.

The top will be dressed with a rise of one-quarter (1/4) inch from face to back. The front edge will be dressed to a curve of one-half (1/2) inch radius; the back edge will be neatly pitched to a line parallel to front edge. The top and face of curb for a depth of eight (8) inches shall be out of wind and shall be axed or pean hammer dressed to show no variation from a straight edge placed on the surface exceeding one-eighth (1/8) inch. Below the eight (8) inches the face shall show no variation exceeding three-quarter (3/4) inch. The ends will be squared and dressed so as to afford close joints not exceeding one-quarter (1/4) inch for a distance of ten (10) inches from the top of the curb.

Circular Curbs. - At intersections and angles circular curbs will be used. Circular curbs will conform in dressing and cross section to the requirements for straight curbs, but the joints are to be cut radially. The radii and lengths will be as shown on the plans or ordered.

Setting. - After the subgrade of the street is approximately established the curbing shall be set with the face vertical, true to line and grade.

The curb trench will be excavated to a depth of twenty-two (22) inches from the top of the curb to a width of ten (10) inches back from the face of the curb; the curbing will be set on two (2) mounds of soft concrete about six (6) inches high, or on two (2) stone blocks six (6) inches thick and not over nine (9) inches square and then tamped to line and grade. The balance of the space under the curb will be filled with concrete, well tamped to afford a solid bearing. Additional concrete will then be deposited back of the curb to a depth of eight (8) inches and will be well tamped and spaded. After the concrete has set, the remaining space to the top of the curb will be filled with fine earth well tamped. Class 111 Concrete will be used for curb setting.

Where driveways exist or are desired, the Contractor will set the curbs to such grade below the adjoining curbs as the Engineer may direct; he will also neatly round off the projecting ends of the adjoining curbs. This work will be done without special compensation.

Where cement sidewalks are injured or disturbed by the curb setting they must be restored by the Contractor without special compensation. In such cases, the existing cement walks shall be neatly cut off on a line nine (9) inches back from the back of the curb and new work conforming in all respects to the requirements for cement walks will be constructed. In case, however, the curb is set to a line or grade different from those of the old curbs, so that a partial reconstruction of the walk is required, such reconstruction will be paid for at the price bid for cement walks; in all such cases a width of nine (9) inches will be deducted from the amount to be paid for.

Existing brick or other walks will also be restored in a neat and workmanlike manner without special pay.

Payment. - All curbing both straight and circular as shown on the plans will be paid for at the price bid per lineal foot. The price will include furnishing the curbing, alt concrete or gravel for bedding and packing, all excavation and all other work or materials necessary to complete the work specified under this item.