90 EXPERIMENT STATION EECOKD. [Vol.::6 



" Electrical blasting was found to be quicker to operate and far more safe 

 than the old cap and fuse method. By the use of a blasting machine many 

 charges may be detonated at the same time, either under the same or different 

 stumps. This method enables the charges to be placed where they are most 

 needed. The holes left are usually smaller and the cost is not greater when 

 the results are taken into consideration. Stump pilers are necessary to efficient 

 land clearing where mechanical pullers are used. When they are equipped 

 with automatic tripping devices piling may be done at the same time as tlie 

 stumps are being burned. When stumps are dropped on a burning pile a more 

 complete burn is secured ; some dirt may be left on the roots and they may be 

 much greener and still burn. The jar of falling stumps is like continually 

 poking a grate fire. . . . 



" Explosives are extremely valuable in certain kinds of ditching work. No 

 matter how wet, brushy, or stony the ditch line may be, if sticks of 60 per cent 

 straight nitroglycerin dynamite can be located within 18 in. of each other in 

 wet ground a serviceable open ditch can be made by the detonation of only one 

 cartridge." 



State highway mileage and expenditures for the calendar year 1915 {U. S. 

 Dept. Agr., Office Sec. Circ. 63 {1916), pp. 8, fig. i ) .—Considerable tabular data 

 are reported on road expenditures and highway mileage during 1915, and a re- 

 view of such matters for the past 12 years is given. 



" During 1915 the total road and bridge expenditures in the United States 

 amounted to about $282,000,000, of which probably not over $15,000,000 rep- 

 resented the value of the .statute and convict labor performed on the roads. 

 Of the cash expenditures of $266,976,399, about $40,000,000 was secured from 

 local bond issues and $53,491,651 from State funds. ... A total of $80,514,699 

 was expended under the supervision of the State highway departments in the 

 construction of 12,437 miles and the maintenance of 51,769 miles of public roads. 



" In 1904 the actual cash road and bridge expenditure in the United States 

 averaged slightly less than $28 per mile of rural roads. In 1915 the cash road 

 and bridge expenditure had increased to an average of $109 per mile of road, 

 and while in 1904 New Jersey led the States with an average road expenditure 

 of $221 per mile, and Nevada was last with $3.72 per mile, in 1915 New Jersey 

 again had the highest expenditure of $475 per mile of rural road and Nevada 

 was last with approximately $17 per mile. 



" While the total road and bridge expenditures have increased about three 

 and one-third times during the last 12 years — the portion secured from local 

 bond issues about eleven times and that from State funds twenty time.s — on the 

 other hand, the portion of this expenditure secured from statute labor has 

 decreased about one-half. Furthermore, in 1904 practically all of the State 

 funds were applied to road construction, not to exceed 3 per cent being devoted 

 to maintenance, while in 1915 about $16,000,000, or 30 per cent, of the State 

 funds were applied to maintenance and reconstruction. . . . 



" During 1915 those States having State highway departments surfaced under 

 such supervision about 8,000 miles, and also improved, by grading and other- 

 wise, an additional 4,000 miles. Thus, of the really constructive road work la 

 the United States last year about one-half was more or less directly under 

 competent State supervision. In addition to this work of construction, the sev- 

 eral state highway departments also supervised the maintenance of 51,769 

 miles of main and trunk line roads." 



Proceedings of the thirteenth annual convention of the American Hoad 

 Builders' Association (Proc. Amer. Road Builders' Assoc., IS {1916). pp. 

 .Y-l-26.}).— The following special articles are includeil in those proceedings: Re- 

 cent Devilopment in the Building of Concrete Roads, by W. D. Uhler; A Con- 



II 



