113 



surface is hard-set, fill the remaining % in. with top sur- 

 face, which is generally composed of 1 part of cement to 

 1 or 2 of good sand, or coarsely ground marble dust or 

 limestone, or trap rock screened to from 1-16 to V6 in. 

 in size. Obtain an even surface by working the top dress- 

 Ing backward and forward with the edge of a level board, 

 which should rest on the strips on each side of the walk; 

 when it is worked sufficiently to fill all pores, trowel until 

 water comes to top; allow sufficient time for water to 

 disappear, then trowel again and get even surface. Too 

 much troweling is objectionable. Blocks should be laid 

 In 4 or 5 ft. squares; lay every other block, returning to 

 lay intervening blocks when the first ones are sufficiently 

 set to allow strips being removed. Tar paper should be 

 laid between joints to prevent the sections adhering to 

 each other. Never use pure cement for dusting, but use 

 equal parts of cement and sand. Dusting should be 

 avoided and only done in cases where it is found too much 

 water has been added to the mixture. Protect the surface 

 against hot rays of sun and against currents of air. Two 

 to 4 in. of earth, kept moist, makes a good cover, but is 

 liable to stain the. walk. 



Walks laid according to the above rule will require 7 to 

 8 Ib. of cement to the square foot. Curbs and gutters 

 should be made in one that they may bind together, and 

 should be made in lengths of 4 or 5 ft. each; the facing 

 or curbing should be finished with a coating of 1 part 

 cement to 1 of sand, carefully worked and troweled as 

 soon as the boards can be removed to admit of same: 

 the edges should be leveled off. 



Cellar Floors: With the exception of the remarks above 

 on depth of excavation, the directions for pavements apply 

 to cellar floors. 



Mortar: For masonry and brick-work use 1 part of 

 cement to 5 or 6 parts of clean, sharp sand, adding about 

 % part of fresh slacked lime to give the mortar a plastic 

 nature; add more lime if necessary. 



SPECIFICATIONS. 



What Specifications for Reinforced Concrete Require. 

 Work Included: This consists of the portion of the struc 

 ture indicated on the plans and is either monolithic or of 

 reinforced concrete. It embraces, providing all materials 

 and labor to construct and complete the work, making and 

 placing of forms, bending and placing of steel, mixing and 

 placing of concrete, removal of forms, removing rubbish 

 and finishing of surfaces. Full detail drawings, showing 



