264 



BULLKTIX 254. 



Since special precautions are necessai\- at every outlet to a tile drain. 



as few of ilieni shouM be made as possible. l"or example, il the i;eueral 



outlet to a series of drains is an 

 open ditch, it is belter to have one 

 outlet than se\eral. Instead of 

 leading each line separately to the 

 open (.litch. they ma\- be joined to 

 a main tile drain which, in (urn. 

 empties into the open ditch at the 

 lowest point. If the main drain 

 is parallel to the open diich and at 

 a tlistanee ivom it equal 10 the dis- 

 tance apart o\ ihe laterals, there will 

 be no increase in amomit oi exeava- 



FiG. 205.-Hamt iwt>[^-m-nls used in ■ j^,, .^|^ ^^^ ^i,^, raiuired. The 



constniiiiiii: t'lc drains. ^ ' 



only difference will be the larger 

 size of tile required by the main. 

 This is set against the advantage 

 of one outlet as compared with 

 several outlets. 



c. Diggiiuj the ditch. 

 ( i) Hand tools. — The tools and 

 equipment needed for digging a 

 ditch by hand are shown in I'ig. 205. 

 Some men open the ditch with a 

 plow, but this is usually considered 

 bad practice because it leaves tlu^ 

 top ragged and interferes with 

 subsequent excavations. The use 

 of the ditching plow is reported 

 by several men to l)e satisfactory. 

 It is very convenient for loosening 

 the soil in the bottom of ihe ilileh 

 and hastens the ]M-ocess of removing 

 the earth with a shovel. The narrow 

 spade — Xo. 5^is the tix^l most used 

 in making the main cxcavatiiMi. 

 There is considerable facility and 

 ease to be learned in this ojieratit^i. 



Jici. 20(1. — Digiiiiu/ a main ditcli i>y 

 hand in stony soil. 



