20 BULLETIN 586, U. S. DEPARTMENT OF AGRICULTURE. 
TABLE 24.—Summary of material and labor costs. 
Cost 
Item. Quantity in working unit. | Totalcost. | per work 
unit. 
Foundation: Cents. 
IMATenial cee ten tec eels kere oe ai ed 39,377.4 square yards. ..:...- $7.50 0.019 
IDOL) sae PN Cera iora arma init hes Seema aa vd aa be tn MALI Neh aaa, tar arate 2,244. 28 5. 699 
Tota ees Passat see eae cece las oie le Sate Sia eae all Somine eels tne hates Me eleek mnianen eis Se laa nists ceeeie 5.718 
Shoulders 
Material] si. see ote ea eck eb scicscccccisce<ces 50,160 linear feet..-.........- 125.00 5745) 
DOD etseatealacrte ae a oe eieole se sls ee sec leiaicn| oie eos cine ties Seneca Wenecae anes 3, 168.05 6.31 
1 No} 1 aren eNO re A open I eS ee a ae Seta ees rt bik etree tiie Stam Ieaaed (arte i AI 6. 56 
Surface: 
Bituminous concrete material.........-..-.... 38,442.6 square yards...-.... 7,095. 40 18. 45 
11000) Se BdS64s Samos Sacco SNeCbes Sao SS SDU NEES S Sab GdagmenoasEes sooderusoepascars 11,970.31 31.138 
TOA SS hae Boe a ee aces Aemtine tell deans aoec owen seen ROE Ee Gaca=| wameemremanee 49.58 
Surface: 
Earth oil-asphalt material.....-..-...--.---.- 934.8 square yards..........-. 223.75 23.92 
DOV eee oe ese since cca clsocs oeiie cen aaelalac cote meinen siete Nemesis acies 429. 56 45.95 
Totals othe Seca me sec wisboe sacite ce sascha ees cate Meee mnie cae esac eee eee eto 69. 87 
Incidental expenses esseae Sass fee cee eee tacit ce ame nctolee Sailer se estas WAO00%00" Sea se eee ee 
RELA WODK S S ee cto oie ccs ease ate eee cimicveinleralaneicla areca | ets aH IR er IPOS Ua rec Rie 230 SLO} eee ee eee 
Lotal'costitiecn sec ccncectencine ec tele elo oi nce see |e oi nine ticloie sseenietlemeinee erie tise 335493390) sence oeeeee 
The above cost data are based on the following unit prices of 
labor: 
HOremeneerececeketcs cased sie Sse acl «DEF cay. of 8 hours. . $4. 00 
Rollermen and skilled laborers..............-:.------ dozer. 4.00 
Malo ON ers her ersane o.oo) Me eee RA Le eee LAN on per day.. 1. 60-2. 40 Ss 
Trucks ee oa aie ans A. Lee ROI SRLS BOE per hour... 1.00 
DRC aM Say ue cuaatse ates Lene ce baper sie, ssc eo cis ciopaes per day. - 4. 50 
SUMMARY OF EXPERIMENTS ON ALEXANDRIA-ACCOTINK ROAD. 
The following describes the condition of the above experiments 
when inspected on January 11, 1917. 
EXPERIMENT No. 1.—BirumInous GRAVEL CONCRETE. 
The surface of this experiment is practically in perfect condition. 
Difficulty has been found already with the rutting of the right-hand 
shoulder going down steep grades, but at the time of inspection there 
was no indication that the edge of the surfacing had begun to shear. 
EXPERIMENT No. 2.—EartH Om ASPHALT. 
This section never had an opportunity to dry out thoroughly, since 
freezing weather came on the day following its completion. During 
thaws it was kept in shape for some time with a road grader and small 
tandem roller, but at the time of inspection was rather badly rutted 
and broken through to the gravel foundation in two places. 
EXPERIMENTS ON THE GUM SPRING-MOUNT VERNON ROAD, FAIRFAX 
COUNTY, VA. 
BITUMINOUS SURFACE TREATMENT ON A NEW GRAVEL ROAD. 
The Mount Vernon Road extends from Gum Spring, in a southerly 
direction, 2.05 miles to the Mount Vernon estate, and is wholly in 
