290 EXPERIMENT STATION RECORD. 



road surface and no subsequent treatment except spreading by brooms was 

 given. The best results were obtained with heavier oils used hot. Dust is 

 largely prevented on roads treated with the heavier oils, but the light, crude 

 oil was found too volatile to produce perninnent results. 



The oiling and tarring of improved roads {Engin. Rec, 5.'f {1906), yo. 8, 

 p. 197). — A discussion of means for abating the dust nuisance on country roads. 

 The inefRcacy of oil treatment when the oil is merely sprinkled upon the im- 

 proved road surface is well shown, it being concluded that " oil treatment is de- 

 cidedly worse than nothing, especially as the result, after a period of dry 

 weather, is no less dust than before and certainly of a not less disagreeable 

 charactei"." When the road surface is swept clean and is perfectly free of dust, 

 crude oil or tar treatment is suggested, but the fact is emphasized that the 

 road surface must be clean and dry and trafhc must not be resumed until the 

 oil or tar is absorbed. This, it is stated, will prevent the raising of dust for a 

 considerable jieriod. 



The concrete block industry as an adjunct to agriculture, E. Freund 

 {Masch. Zttj., >, {1906), ^os. 11, pp. 124-126, fi(js. 2; 12, pp. 133, 134; 13, pp. 

 145-lJil, figs. 6). — The writer describes a molding machine for the manufacture 

 of concrete brick, and blocks for various uses; for example, cornices, lintels, 

 arches, etc., together with a hand or power driven machine for the mixing of 

 materials. The proportions of the various ingredients are given and also a 

 discussion of the relative lengths of time of setting with different grades of 

 cement. The total cost for the manufacture of 1,000 briclv is given as $2.G5 

 using lime and cement, and $3.20 using cement alone at the prices for the re- 

 spective materials prevailing in Germany. 



The number and distribution of silos in "Wisconsin, G. N. Knapp {Wis- 

 consin Hia. Ilpt. 1905, pp. 363-366, fig. 1). — A statistical record compiled from 

 reports by assessors on the number of silos in the various counties of Wisconsin. 

 The number of silos per county is found to be usually in direct proportion to the 

 number of dairies. The total mniilier reixirted foi' the State was TIG. 



Motor trucks and motors at the fifth automobile show, M. Hardy {Ann 

 Gemhloux, 16 {1906). Xos. .',. pp. 213-23.5, figs, lo ; 6. pp. 3o9-3S3, fii/s. .'M.— The 

 Avriter describes a large inunl)er of power trucks, giving data as to tbeir per- 

 formance and structural details. lie compares gasoline and steam motors in 

 their applicatiiin to motor trucks and finds that " if one considers the progress 

 Avhich has l)e('n made and the advantages of steam, steam motors should be in 

 more favor tlian the other. So far as starting and changes cf velocity are 

 iconcerned, particularly for heavy trucks, steam motors possess an elasticity 

 .■and pliancy \vl)icli do not lu'long in the same degree to the intei'nal combustion 

 motor." 



A so-called " ent'rgy-car " is descril)etl, wliicli is designed especially for 

 rise in agricultural oi)erations. It consists of a light wagon carrying an 

 explosion motor cnuplcd to an electric generatcr by a special device. The 

 generator is so wound tliat it may operate either as generator or motor, and it 

 is connected to a small storage battery carried by the wagon. The batteries 

 furnish an additional i)ower when the load is greater than the explosion motor 

 can develop normally. By the entire combination a flexibility of control, ease, 

 and certainty of operation are obtained which would not be possessed b.v the 

 explosioia motor alone, to which are condiincd tlic advantages tliat it may 

 deliver mechanical energy at the wagon or electrical energy at a distance to be 

 used for power or electric ligliting. 



With reference to the economy of different types of motor, tlie writer regards 

 the nK)tors of the automobile type much less economical and durable than 

 other types of njotor due to their high velocity of rotation and greater cylinder 



