392 EXPEKIMENT STATION EECOKD. 



Investigations concerning dust formation on broken stone roads, and 

 experiments in preventing it, F. Bernhard {Untersuchiingeii iibcr die 

 Ursaclicti der Bildung des StaWbes auf Steinschlagstrassen und iiber VersucJie 

 zur Bekdmpfung desseJhcn. Leipsic, 1908; rev. in Osndhts. Ingen., 32 (1909), No. 

 21, pp. 862-364). — This book contains the results of experiments made on tlie 

 streets and roads of Carlsbad by the author, who is city engineer. In connec- 

 tion with the reports on studies of dust formation there are tables showing the 

 weight of different road materials and their resistance to crushing, the wearing 

 power of the basalt which is used as a road material there, and data on the 

 weight of teams and amount of traffic on the streets experimented with, as well 

 as other facts bearing on the life of the road material, including rainfall and 

 temperature data. 



The dust preventives experimented with included water, tar, calcium chlorid, 

 magnesium chlorid, and several of the more prominent commercial prepara- 

 tions. The cost and efficiency of these materials in laying and preventing dust 

 is reported upon in the book, and there is also in the review a summary of these 

 giving briefly their composition and cost, condition of the road experimented 

 on, and the nature and amount of traffic on it. 



Experiments in dust laying, K. M. ^Ieyer (Ztschr. Transport w. u. StraS' 

 senMu, 26 {1909), No. 15, pp. 301, 302). — Experiments in laying dust with am- 

 moniacal wastes have been made in the vicinity of Berlin, and a brief descrip- 

 tion of them is given in this article. The liquid was effective in keeping down 

 the dust and preventing its formation even in spots exposed to the direct rays 

 of the sun, and the writer considers that there are great possibilities for these 

 wastes, especially in municipalities owning their gas plants. 



[Tests of wagon draft and axle friction], J. B. Davidson {loioa State Col. 

 Agr. Rpt. 1901-8, pp. 190-197). — An account is given of dynauometer tests made 

 at the Iowa Station to determine the draft of wagons. The results are tabu- 

 lated accoi'ding to kind of road surface and size of wheels and tire, with the 

 amount of net load under different conditions of the surface as to firmness, 

 dryness, and frost. 



Tests were also made to determine the relative advantages of different types 

 of wagon axles and bearings and the effectiveness of lubricants, and the results 

 of these are given in tabulated form. In order to eliminate rolling friction in 

 these tests the axle was inverted, lifted free from contact with the ground, and 

 suspended by means of leaf springs from a rigid support. The method is 

 described in detail. The results are considered inconclusive as regards the 

 different brands. 



Trials of manure distributers (Jour. Roy. Agr. Soc. England, 69 (1908), 

 pp. 173-182, figs. 4). — There were 19 fertilizer distributers entered in these 

 trials, and this account mentions briefly the peculiarities of each and its per- 

 formance. 



Descriptions are given of 2 distributers which were awarded gold and bronze 

 medals, respectively. The first of these is stated to be unusual in construction 

 in not having a stirring device. The bottom of the hopper is a platform moving 

 circumferentially at a slow rate, carrying the material round to the opening, 

 surmounted by a star or finger wheel moving in conjunction with it. which 

 forms an effective conveyor and also serves to crush lumps against the fixed 

 scrapers. The characteristics of the second machine are a combination force 

 feed and revolving disc which secures a regular output and a discharge free 

 from clogging. There are adjustable brackets so that the delivery discs can be 

 readily tilted and the position of the discharge spouts so altered as to give 

 equal distribution on uneven or hilly land. 



