486 EXPERIMENT STATION RECORD. 



the larger gasoline engines fonnd in the laboratory for the most advantageous 

 use of alcohol." 



The results obtained are summarized as follows : 



"(1) The higher heat value of 94 per cent alcohol is but 08 to 71 per cent 

 that of gasoline. 



"(2) The lower heat value (the value more nearly attained in practice) of 

 94 per cent alcohol is but G6 per cent to 69 per cent that of gasoline. 



"(3) When used for the production of light, 94 per cent alcohol will produce 

 from 53 per cent to S5 per cent as much light as an equal volume of gasoline 



"(4) Alcohol of 94 per cent purity must be sold for from 11 to 17 cts. per 

 gallon to compete with gasoline for lighting purposes at 20 cts. per gallon (the 

 present retail price of gasoline iu Ames). 



"(5) Alcohol, when used iu a generator lamp, will produce from two to four 

 times as many candle power hours as kerosene in a wick lamp. 



"(0) It was found impossible to soot the mantels of any of the lamps with 

 alcohol. 



"(7) Alcohol of 94 per cent purity, when used in engini'S designed for gaso- 

 line, has but 08 per cent to 85 per cent the value of gasoline in the production 

 of power. 



'•(S) To compete with gasoline at 20 cts. per gallon for use in gasoline 

 engines, 94 per cent alcohol, must be sold for from 13 to 17 cts. per gallon and 

 90 per cent alcohol from 11 to 15 cts. per gallon. 



"(9) None of the engines could be started readily with alcohol, although a 

 few could be started with less difficulty than others. 



"(10) After having once been started with gasoline and warmed up, the 

 carburetors as -designed for gasoline vaporized the alcohol successfully, except 

 in once instance. ♦ 



"(11) No doubt the gasoline carburetor can be readily changed to permit the 

 use of alcohol as well as gasoline in the same engine. 



"(12) Experimental work does not include tests of the special designed 

 alcohol engine which should show better economy in the use of alcohol. 



"(13) Gasoline can not be used readily in a special designed alcohol engine 

 using high compression on account of pre-ignition. 



"(14) The odor of the exhaust of an engine when using alcohol is not as 

 unpleasaiit as when using gasoline. 



"(15) Alcohol is much more pleasant to handle. 



"(10) There is much loss danger from fire when using alcohol than when 

 using gasoline, owing to the fact that alcohol does not vaporize as readily as 

 gasoline and its flame may be extinguished with water." 



Public-road mileage, revenues, and expenditures in the United States in 

 1904, M. O. Eldredge ( V. S. Dcpt. Ayr., Office Pub. Roads, Bui. 32, p% 100, figs. 

 2). — This bulletin consists largely of data already reported for each State in 

 Circulars 39-40 and 48-87 of the Office of Public Roads, but the results of the 

 whole investigation are assembled for a more convenient study and discussion, 

 " in order that such comparisons and deductions may be made as will aid the 

 public in locating defects in our present systems of road management." 



" In 1904 there were 2,151,570 miles of public road in the United States. Of 

 this mileage, 108,232.9 miles were surfaced with gravel, 38,621.7 miles with stone, 

 and 0,809.7 miles with special materials, such as shells, sand-clay, oil, and brick, 

 making in all 153,664.3 miles of improved i*oad. From this it follows that 7.14 

 per cent of all the roads in this country have been improved." 



The total expenditures during 1904 amounted to $79,771,417.87. This is $37.07 

 per mile of public road, or $1.05 per capita. 



