506 



STATE BOARD OF AGRICULTURE. 



Fig. 28. Shows the connection when tile are fitted and in place. 



DESIGNATING THE SUB-MAINS AND LATERALS AND NUMBERING THEIR GRADE 



STAKES. 



In keeping the field notes it is desirable to have some definite method 

 of designating the mains, sub-mains and several laterals. The main is 

 usually designated simply as main while the sub-mains and laterals 

 are designated by a name or symbol which indicates the particular stake 

 in the main or sub-main at which they discharge their water. A sub- 

 main discharging its water at a point where the grade stake upon the 

 main was No. 7 for example, would be designated Sub-M and the grade 



stakes along that sub-main would be designated Sub-M 1, 2, 3, &c. A 



lateral connecting with a main at grade stake 10 would be designated 

 Lateral 10 — and its grade stakes would be designated as Lateral 10-1, 2, 

 3, &c, or Lat. 10/1, 2, 3, &c. A lateral connected at grade stake G on 

 sub-main 7, would be designated as Sub-M 7 and its grade stakes would 



6 

 be designated as Sub-M 7 1, 2, 3, &c. and would appear in column one 



6 



in the note as 



The elevation of the ditch or any sub-main or lateral should be such 

 that the center of its tile shall center with the tile into which it dis- 



