588 



EXPERIMENT STATION RECORD. 



[Vol. 36 



Truck and tractor engines, H. L. Horning {Gas Engine, 18 {1916), No. 12, pp. 

 590-600, figs. 3). — This paper deals witli "first, tlie demands made on modern 

 truck and tractor engines ; second, the most serious prol)lems the engineer has 

 met in fulfilling the demands ; and third, the lines the development of the future 

 is likely to take." Fuel and features of design receive special attention. 



Exhibition trial of motor tillage implements {Trans. Highland and Agr. 

 Soc. Scot., 5. scr., 2S {1916), pp. 281-296, figs. 5; abs. in Jour. Bd. Agr. [London], 

 23 {1916), No. 6, pp. 600, 601). — This is a detailed report of trials previously 

 noted (E. S. R., 34, p. 788). 



[Special tests of tractors, 1915], M. Ringelmann {Bui. Mens. Off. Renseig. 

 Agr. [Paris], 14 {1915), pp. 1116-1182). — Tests of seven American tractors when 

 traveling without load and when on mechanical cultivation, including draft 

 tests, are reported. The more important results of the tests over soil without 

 load are given in the following table: 



Tests of tractors imthont load. 



Calcu- 

 lated 

 horse- 

 power. 



26 



Condition of wheel rims. 



Comers and projections 



GaK-s 



Corners and projections 



Calks 



Fixed projections 



(■projections and pointed are! 



\Smooth 



(Strips 



■^Strips and pointed arches... 

 IComers •'- 



Average 



speed 

 per hour. 



'elrrs. 



5, 14S 

 3,748 

 5,364 

 2,232 

 3,276 

 4; 608 

 3,060 

 3,060 

 3,240 



Fuel con- 

 sumption 

 per ton 

 Inii. 



Kilogram. 

 0.88 

 .39 

 .28 

 .74 

 .35 

 .30 

 .24 

 .34 

 .33 

 .36 



State of soil. 



Slippery 



Verv slippery . 



Dry. 



Slippery 



Very dry 



T>ry 



After rr.m 



do 



Sound 



Slip of 

 driven 

 wheels. 



Per cent. 



3.0 

 6.3 

 1.5 

 3.0 



. 5 

 1.5 

 3.0 

 2.5 



.5 



The more importiint iisuils of ii;(>f lianical plowing tests are given in the 

 following table : 



llceltanical ploioing tests. 



Un the equation t^mP, in which <=averagc draft and P=drive-wheel presi?ure on the soil. 



Public tests of mechanical cultivating apparatus in 1916, P. Buchard {Vie 

 Agr. et Rurale, 6 {1916), No. Jfl, pp. 260-269, figs. 6).— This report reviews the 

 more important results of mechanical plowing tests made at five different 



