DUST PREVENTION AND ROAD PRESERVATION. 9 
Table 10. — -Unit costs. 
Labor (per day of 8 hours): 
Superintendent $10. 00 
Foreman $4. 50 
Rollerman $3. 50 
Engineer for mixer $4. 00 
Carpenter $3. 50 
Laborer $1. 60 
Team .$5. 00 
Materials i. o. b. nearest siding: 
Sand per ton. . $0. 70 
Gravel (for use in concrete gutter and base) do $0. 85 
Gravel (for use in concrete pavement) do $0. 95 
Crushed limestone do $1. 10 
Crushed trap rock do $1. 35 
Cement per barrel . . $1. 51 
Vitrified brick per M. . $20. 00 
Oil asphalts (cents) per gallon. . 10. 13 
Fluxed native asphalts (cents) do 14. 10 
Refined coal tar (cents) do ... . 10. 92 
Water-gas tar preparation No. 2 (cents) do 8. 42 
Water-gas tar preparation No. 1 (cents) do 7. 22 
Native asphalt emulsion (cents) do 13. 00 
Residual petroleum (cents) do 10. 70 
4-inch vitrified clay tile (delivered on work) (cents) .per foot. . 6. 69 
Contract price for. unloading and hauling materials from siding to work (aver- 
age haul 3,100 feet): 
Sand and gravel (cents) per ton. . 40 
Crushed stone (cents) do 45 
Cement (cents) per barrel . . 10 
Machinery (per day) : 
Concrete mixer $10. 00 
Roller $5. 00 
Table 11. — Concrete gutter. 
Total length feet. . 5, 631 
Quantities of materials per linear foot of gutter: 
Cement barrel . . 0. 101 
Sand. cubic yard . . . 029 
Gravel . do .050 
Cost data (cents per linear foot): 
Cement 16. 06 
Sand 4. 38 
Gravel 8. 44 
Forms 1. 81 
Foreman 2. 05 
Carpenter and helper 2. 05 
Finisher and helper 3. 24 
Labor 16. 49 
Total 54. 52 
Total cost of gutter $3, 070. 02 
41701°— 14 2 
