THE MANGUM TEKRACE. 



saving machinery is in a great measure dependent upon the cultiva- 

 tion of southern lands in larger and less irregular bodies. In this 

 system, where the land has only a medium slope, it is perfectly 

 feasible to cuhivate directly over the terrace on a line with the 

 o-reatest level of the field. This one feature saves a very large 



& 



amount of labor. 



HOW TO LAY OFF AND CONSTRUCT THE MANGUM TERRACE. 



The terrace as developed and recommended by Mr. JSIangum is 

 laid off on a uniform grade of 1^ inches to 1-t feet. This is a 

 slightly higher grade than is usually given a terrace. In many 

 hundreds of actual tests, however, it has been found to give entire 

 satisfaction. The reasons why a grade higher than usual may be 

 permitted are (1) that the water is spread over a broad flat surface 

 instead of confined to a narrow channel and (2) that as the whole 

 area is cultivated the soil is kept roughened, which impedes the 

 velocity of the water. On some soils, however, even a higher grade 

 may be used, while 

 on very light, sandy 

 soils probably a lower 

 grade would be more 

 satisfactory. 



A level for laying 

 off these lines can be 

 constructed on any 

 farm. Make a big 

 letter A, 14 feet 

 across the base. ( See 

 fig. 2.) On the bar across the apex of the letter A, one end of which 

 bar is fastened with one nail, place an ordinary farm spirit level. Set 

 up on an absolutely level surface. Get a little block, li inches high, 

 and put it under one of the feet of the A-frame. Adjust the loose end 

 of the crosspiece until the level-bubble remains in the center; then 

 fasten the loose end of the crossbar upon which the level rests. 



Xow, iret a bundle of broom-sedge straw or other material suitable 

 for use in marking out the line of the terrace and start across the 

 field to lay out a line with the desired fall. In going up the grade 

 always keep to the front the end of the letter A which rested on the 

 block. Stick a broom straw as a marker where you start at the side 

 of the field and adjust the front end of the A-frame by moving it 

 from side to side until the bubble is in the middle of the level. Put 

 the rear end then where the front end was, and continue the process 

 across the field, sticking a broom straw at each point. Thi- marks 

 out the grade line. 



[Cir. 04] 



Fig. 2. — A-sIiaped frame level for laying off the terrace 



line. 



