114 



June 27. and the work was continued with, road oil No. 7. The pres- 

 ence of fresh timothy in half the field so held the chinch-bugs back in 

 the stubble that the lines were kept up for twenty-six days, at the 

 following expense : 



Plowing the ridge (1% days' labor with man and team) $ 4.50 



135 hours ' labor pouring oil and tar 27.00 



3 barrels road oil at $3.50 10.50 



1 barrel coal-tar, at $4 4.00 



Total for materials $14.50 



Total for labor 31.50 



$46.00 



Cost per day per mile: 



Materials ' 5(i 



Labor 1.21 



$ 1.77 



The diminished cost as compared with that of 1911 was due in part 

 to the substitution of road oil Xo. 7 for Xo. 6 and in part to the less 

 trying character of the season. AVhile the average mean temperature 

 for June and July in the chinch-bug area was nearly as high as in 

 1911. there were no records of as much as 100 degrees in the shade in 

 either month, and the rainfall of June and July was above the normal 

 by .58 of an inch for June and 1.68 inches for July instead of 2.4 

 inches and 2.16 inches below the normal in the year preceding. The 

 thicker road-oil lay much longer on the moister earth, with a resultant 

 saving in both labor and material. On the other hand, timely rains 

 supported infested corn against the drain of chinch-bug injury so 

 that even unprotected fields suffered much less than in 1911. 



Altho there were no experimental or demonstration fields in Ma- 

 coupin county in 1912. Mr. Flint's statement of farmers' operations 

 may be taken as a virtual substitute. Forty barrels of road oil No. 

 7 and about twenty r five barrels of coal-tar were used in the vicinity of 

 Carlmville, Plainview. and Bunker Hill. The road oil Xo. 7 gave 

 general satisfaction, and was evidently about as thick a substance of 

 its kind as could be used to advantage. It was repeatedly noticed., 

 indeed., that where Xo. 8 was used it could be crossed by chinch-bugs 

 in the morning and the evening, when the nights were cool. It took 

 from four to six times as much coal-tar as road oil Xo. 7 to keep up a 

 given length of line. The ground was usually prepared for the road- 

 oil line by plowing a very shallow furrow around the field and trim- 

 ming this with a hoe to leave a hard level surface. The very best bar- 

 rier, however, was one prepared by dragging a heavy plank in the edge 

 of a corn field to make a hard smooth surface, and then driving an 

 empty wagon along in such a way that one of the wheels made a slight 

 groove down the center of this path. Road oil poured in this groove 

 made a line which lasted for twenty days with no renewal except to 

 be touched up here and there occasionally where there were small 

 breaks. 



