City roads and pavements suited to cities of moderate size. . he center ordinate, or total crown,as unity; then the successive ordinates, measured upfrom the base-line, will be: At center, , .99, .97, .94,•89, .83. -75. -66, .55, .44, .30, 16, .0 at curb. Orstretch a line from curb to curb on level with thecenter, and measure down the corresponding if the width is 30 feet from curb to curb, and thecrown has been determined to be half a foot, the ordi-nates measured down at intervals of i % feet will be ininches and decimals. At the center o inches—,,,, ,
City roads and pavements suited to cities of moderate size. . he center ordinate, or total crown,as unity; then the successive ordinates, measured upfrom the base-line, will be: At center, , .99, .97, .94,•89, .83. -75. -66, .55, .44, .30, 16, .0 at curb. Orstretch a line from curb to curb on level with thecenter, and measure down the corresponding if the width is 30 feet from curb to curb, and thecrown has been determined to be half a foot, the ordi-nates measured down at intervals of i % feet will be ininches and decimals. At the center o inches—,,,, , , , , , , , inches at curb. This shows a side-slope of aboutfive per cent on the third next the curb. These fig-ures may be useful in making a template for fixingthe curve of a pavement-surface, or for forming thesand-cushion of a brick pavement as described onpage 95- For Macadam, it is usual to consider that the con-ditions to be met are reversed, and it being necessaryto prevent storm-water from following the road-surface, 34. CITY ROADS AND PAVEMENTS. the crown for macadam is increased as the slopeincreases; one-half inch per foot being usual on levelgrade, and a maximum of three-quarters inch per footon steep slopes, increasing to one inch on excessiveslopes. This produces in theory a ridge in the center,with a straight slope of 5 ^ inches on each side for alevel 22 foot roadway. But in practice, the roller flats thecentral ridge down, and produces a curve which isflat in the center and slopes most at the sides, which isthe form desired. FALLS ON DIFFERENT PAVEMENTS. As to the relative liability to accidents from slippingof horses feet upon different pavements, observationswere made for Captain (now General) Francis V. Greene,M. Am. Soc. C. E., during a period of six months onthirty-six various streets in ten different cities, viz.:New York, Philadelphia, Chicago, Boston, St. Louis,New Orleans, Washington, Buffalo, Louisville andOmaha. The resu
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectstreets, bookyear1902
