lOl'o] RURAL ENGINEERING. 187 



Motor vehicles and their engines, K. S. Fraseb and R. B. .Ionrs (New 

 York: 1). Van Aostnind Co., lOlf), pp. ]\-{-.i52, fiys. 278)".— This l)()()k- presents 

 a collection of elementary, theori'tlcal and practical information for assistance 

 in the operation, upkeep, and adjustment of meclumically propelled vehicles. 

 The fundamentals of gas motor operation, as well as the care and operation 

 of the principid accessories of motor vehicles, are discussed in detail. The 

 last four chapters present the results of the authors' observations and expe- 

 rience on the economy and efficiency of operation of a large number of trucks, 

 tractors, and automobiles. 



Motor fuels, E. W. Dean (Jour. Franklin Inst., ISO (1920), No. 3, pp. 269- 

 302, fif/s. JS). — The object of this paper is to provide information of general in- 

 terest regarding (1) the production and use of gasoline, (2) the physical and 

 chemical properties of gasoline and the quality of the products marketed dur- 

 ing 1917 and 1919, and (3) present tendencies in the development of substi- 

 tutes for gasoline. 



"As regards the real possibilities of gasoline substitutes, it now seems 

 probable that oil shale may in the future prove an important source. . . . 

 Another tyi>e of fuel whicli offers unlimited possibilities for the future and 

 which is already being developed to a certain degree is alcohol. The problems 

 to be solved before this comes into general use are apparently the development 

 of cheaper methods of production and the development of suitable types of 

 engines. . . . 



" The type of gasoline substitute which is of most importance at the present 

 time is the mixture of hydrocarbons obtained as a by-product in the coking of 

 coal. . . . Benzol and other coal-tar distillates have certain disadvantages 

 when compared with petroleum gasoline, but have other very marked ad- 

 vantages, particularly in freedom from tendency to knock. An additional ad- 

 vantag«' lies in the fact that they have a considerably higher calorific value per 

 unit volume, and as this is the basis on which the user buys, he gets more for 

 his money than he would from petroleum gasoline. . . . 



"Petroleum gasoline i^ a type of fuel for which present equipment has been 

 designed and for which it is eminently satisfactory. It is believed, therefore, 

 that when striking claims are made for the superiority of any gasoline substi- 

 tute these should not be taken too seriously. The substitute fuel should be 

 given a fair trial, but the user should be satisfied if it is as good as gasoline and 

 should not expect it to be notably superior." 



The possibilities of new fuel mixtures for internal-combustion engines, 

 E. Humboldt (Pouer, 50' (1919), No. 11, pp. J,1R-J,20, fig. 1).— This article deaLs 

 with the production of a cheaper and cleaner substitute for gasoline by mixing 

 a small amount of ether and alcohol with engine distillate. Economical methods 

 for the production of alcohol and ether are described. 



P'rom experiments it is concluded that the addition of alcohol to the ordi ary 

 petroleum fuels prevents them from leaving any carbon deposit in the engine 

 and insures thorough, clean combustion. The addition of the ether insures a 

 better solution of the alcohol in the hydrocarbon. 



[Gasoline analyses], R. E. Rose and E. T. Caslkr (Fla. Quart. Bui. Dcpf. 

 Agr., 30 (1920), No. 1, pp. i/8-/////).— Analyses of 344 samples of gasolines 

 offered for sale in Florida during 1910 and taken by inspectors before the en- 

 forcement of the State gasoline inspection law, are reported, together with 

 analyses of 28 samples of gasoline collected for official inspection under the 

 inspection law in 1919. 



f Kerosene analyses], R. E. Rose and E. T. Casleu (Fin. Quart. Bui. Dcpt. 

 • l.'/r.. 30 (1920), No. 1. pp. i^J-i-JS).— Analyses of .51 samples of kerosene? 

 ]Sr)972°— 20 7 



