Portland cement, and compositions that resemble that material, are used for a variety of purposes in Vienna; among others, for making artificial-stone sidewalks. A dry soil is to be preferred; but if it should be moist, marshy, or a clayey soil, great care must be taken to make the foundation as firm as possible. This will be a matter in which the workman must exercise his own judgment and experience. The first layer of concrete should be composed of 1 part cement and 3 of coarse gravel. This is laid upon the soil which is already smoothed and graded. The thickness of this layer will vary according to the nature of the soil. The second layer should be mixed in equal parts, 2 of cement and 2 of fine sand. Then a third layer, equal parts cement and sand, completes the work.

The workman finishes a piece about 3 ft. wide, from the wall to the curb, before he attempts to touch another length. The first layer is to be well rammed down to make it compact; the other 2 layers are to be floated on as quickly as possible. It requires about 4 days for the sidewalk to harden. During this time it should be frequently sprinkled with water. Spring or autumn is the best season in which to lay the cement. Summer is too dry, and winter weather is too severe. A sidewalk thus prepared will last about 15 years.

The curbing is also made of cement. This is generally formed in a mould. The joints are made to fit into each other to prevent shifting after they are set. The body of this curb is composed of 3 1/2 parts broken stone or gravel to 1/2 of cement; it is coated with a surface of equal parts fine sand and cement. Steps are made in the same way. These would serve for door-steps if they had no weight to carry. The makers of such concrete-work claim that, when properly hardened, it is stronger than stone. This is doubtful.

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