592 EXPERIMENT STATION RECORD. 



rred by the engine is used not only for tlie operation of the evaporator, but also 

 for pumps, oat rollers, shredders and choppers, a circular sa\\-, and nnlk 

 separators. 



The capacity of the plant is 5 tons of raw potatoes of 19 per cent starch con- 

 tent per 24 hours. With less starch content the capacity is correspondingly 

 reduced. The total running expenses per 24 hours are .$G.70. The claim is 

 made that this sort of plant is very profitable, as the dried potatoes can be 

 shipped to distilleries and other potato-using plants at great saving in transpor- 

 tation charges, or in case the market is not favorable, the potatoes can be used 

 as a cattle food, a use for which they are well adapted. 



Tarred road. Successful results in Prance — Application methods {DitUi/ 

 Consular and Trade Rpts. [C. ,S'.]. 1006, No. 2700, pj). 1-3).— In refutation of a 

 ibtatement to the effect that tarred roads are unsuccessful in France it is 

 affirmed on reliable testimony that tarred roads have been uniformly successful 

 wherever the conditions have been normal and the work properly performed. 

 The method of tar treatment in France is similar to that elsewhere. In 

 the first coating about 1 gal. of liquid tar for 3 sq. yds. is given ; in the 

 second coating, 1 gal. for 4 sq. yds. 



The tar must be laid on a thoroughly dried and swept surface, otherwise it 

 does not harden readily and is picked up by the wheels of passing vehicles, a 

 circumstance to which is probably due the adverse criticism. Cleaning by 

 machinery does not do the same injury to tar-treated roads as to the ordinary 

 macadam and the protection from wear and tear from this source, as well as 

 the better wearing qualities under the ordinary wear and tear of traffic condi- 

 tions, is said to produce an economy which balances the extra cost. 



New road-tarring machine {>Si(rrcijor, 30 (1906), A^o. 767, p. 3S0, fig. 1). — A 

 machine is described by \Ahich the operations of cooking, sprinkling, and spread- 

 ing by brooms are effected simultaneously. The tar is applied at a temperature 

 of 200° F., and it is claimed that a surface of 2,000 sq. yds. may be uniformly 

 covered per hour. The cost of the first two coats is put at about l*d. per sciuare 

 yard, with tar at lid. per gallon. 



A new fertilizer-spreading machine {Mascli. Ztg., Jf (1906). Xo. 17, pp. 

 200, 201, figs. 3). — In the operation of the usual machine in which the fertilizer 

 is forced by a roller through holes in the bottom of the receptacle a serious diffi- 

 culty is often experienced by clogging, due to excessive moisture in the fertilizer. 

 To obviate such trouble and to properly disintegrate the material an apparatus 

 has been devised in which " the bottom of the receptacle is formed of two pecul- 

 iar spring brushes whose ends press upon a roller rotating between them. The 

 roller is provided with projections arranged in a spiral, and when in operation 

 these projections strike the brushes, thus disintegrating the fertilizer and allow- 

 ing it to escape through the triangle-shaped orifices caused by the opening of the 

 springs forming the brush. The volume of fertilizer to be distributed is varied 

 by changing the number of revolutions of the roller, which "is connected to the 

 wheels of the machine by interchangeable gearing." 



Cements, limes, and plasters. Their materials, manufacture, and prop- 

 erties, E. C. Eckel (Nciv York: John Wiley d- Sons; London: Chapman d 

 Hall. Ltd., pp. XXXIV+712. pis. 8. figs. J.5?).— In this volume the author has 

 summarized all the existing information on limes, plasters, and allied materials, 

 the work covering the composition and character of the raw materials, methods 

 of manufacture, and i)roperties of the various cements. 



