DUST PKEVENTION AND ROAD PRESEEVATTON, 1915. 37 



Table 39. — Analysis of residual aspMltic petroleum used at Buena Vista, Fla. 



Specific gravity 25°/25° C 0. 992 



Viscosity, Engler, 50 c. c. at 100° 0. specific 31. 5 



Float test at 32° C, time 2^ 44^^ 



Ploat test at 50° C, time V 04^^ 



Loss at 163° C. 5 hours, 20 grams, per cent 75 



Float test of residue at 50° C, time 1^ 30^^ 



Per cent of total bitumen insoluble in 86° B. naphtha 13. 02 



Fixed carbon, per cent 8. 20 



Soluble in CS2 (total bitumen), per cent 99. 91 



Organic matter insoluble, per cent 09 



Inorganic matter insoluble, per cent 00 



Total, per cent 100. 00 



Table 40. — Cost data on construction of coralline-roch road. 



Materials used : 



No. 2 stone, cubic yard per square yard 0. 083 



Sand, cubic yard per square yard 014 



Bitumen, gallon per square yard 906 



Coat per square yard: 



No. 2 stone |0. 1546 



Bitumen 1243 



Spreading No. 2 stone 0175 



Heating and applying bitumen 0075 



Spreading sand 0105 



Rolling 0079 



General expense 0186 



Total 3409 



Total costs for surface: 



Quarrying and crushing No. 2 stone, 227 cubic yards 302. 85 



Loading and hauling No. 2 stone to road 118. 00 



Spreading No. 2 stone 47. 50 



Bitumen on siding, 2,465 gallons 330. 31 



Unloading and hauling bitumen to road 8. 00 



Heating and applying bitumen 20. 40 



Spreading sand, 38 cubic yards 28. 75 



Rolling 21. 60 



General expense 50. 60 



Total 928. 01 



Coat of preliminary work : 



Grading 132. 11 



Shaping subgrade, 2,722 square yards 51. 65 



Gathering and hauling foundation stone, 454 cubic yards ]25. 90 



Spreading arifl sledging foundation stone 95. 00 



Rolling foundation stone 10. 80 



Total 415.46 



