990 EXPERIMENT STATION EECOED, 



tank are stretched taut up to the lever and the position of the latter marked 

 on a board held vertically. By repeating this process for various heads, 

 keeping the chains of the same length, a series of lines are obtained on the 

 board. A curve is drawn tangent to these lines and the' board sawed to the 

 curve. If the lever is now placed upon and allowed to roll on the curve, the 

 relation between the head of water and the size of the outlet must be such as to 

 give a constant dischai'ge from the outlet. 



Thirteenth annual report of the commissioner of public roads, 1906 (Aiiii. 

 lift. Voinr. J'uh. Ronds y. ./.. 13 ilDiKJ). pp. J76, pis. l.>. map. J). — A report 

 covering road construction and improvement in the various counties of New 

 Jersey, giving the total mileage and cost. A number of papers, contributed by 

 the county engineers on various subjects connected with road construction, and 

 statistical data on the detail cost of various roads, together with the standard 

 State specifications, form the greater portion of the report. 



The value of oil in road improvement, A. Dickens (Ka)isa.s .s7«. Bill. I.'f2, 

 pp. 113-12 'f, fig. 1). — This bulletin contains the results of the experiments con- 

 ducted in certain parts of Kansas, as authorized by the legislature, on the use 

 of crude oil for the improvement of public roads. Several short road sections 

 were treated at Manhattan. Hutchinson. Maple Hill, and at Garden City, the 

 experiments consisting in general of first putting the road .in a fair condition, 

 and then plowing it to a uniform depth and thoroughly pulverizing it with har- 

 row and disk. Where the soil was loose sand, the I'oad was merely worked to 

 the proper form. The oil applied was what is known as residuum from the 

 refineries, preliminary laboratory tests having shown that 1 gal. of residuum 

 was equal in road-making qualities to from 2 to 4 gal. of the various oil samples. 

 The oil was applied by a special sprinkling arrangeme^lt attached to a street 

 sprinkler, the amount used varying from 0.5 to G gal. jier square yard according 

 to the conditions of the experiment. Observations were made upon the behavior 

 of the road under traffic, and although the tests are regarded as incomplete the 

 following conclusions were drawn : 



"The thorough mixing of the earth and soil to a sutHcient deiith to form a 

 waterproof crust is necessary. For heavy traffic, not less than i; in. is desir- 

 able ; for light driving, o or 4 in. should be sufficient. 



" Oil roads will probably re(]uire repeated applications cf oil. but it now seems 

 that the amount required will decrease annually as the roads liecome smoother. 



" With residuum at 8(5 cts. to $1 per barrel f. o. b., the total cost of road varied 

 from .$52.5 to ^l.?,()0 per mile for an IS-ft. road." 



Alcohol motors in agricultural operations {Dciit. Laiuhr. ]'rcs.^i\ 3'/ {1007), 

 No. 26, pp. 211, 2 IS, fig. 1). — The writer takes up some of the advantages of the 

 alcohol motor in agricultural oiierations in Germany. Among these, he refers to 

 the facility with which the motor can be put in operation as couqiai-ed with the 

 steam engine, in case it is desired to complete harvesting and threshing opera- 

 tions in anticipation of approaching bad weather, when the time required to fire 

 a boiler and get up steam might mean the loss or injury of a portion of the 

 crop. The absence of smoke and spai'ks is also tliought to be an advantage over 

 the steam engine in field use, as is also the fact that the use of the alcohol motor 

 does not necessitate the expense of hauling water, the water consumption of the 

 alcohol engine for cooling pxu'poses being only about I gal. per horsei)ower hour, 

 or 24 to 26 gal. water per day for a 12-horsepower engine. 



To show the relative cost of different fuels, some tests are reported on a 

 special motor in which, by the addition or removal of plates on the iiiston head, 

 the compression c;in be conveniently changed for various fuels, such as alcohol 

 and the other usual hydrocarbons, a compression of 15 atmospheres being used 



