THE FLOW OF WATER IN DRAIN TILE. 



Table 6. — Individual tile formulae and revised intercept values. 



37 



1 



2 



3 



4 



5 



6 



7 



8 



Tile. 



Velocity. 



Num- 

 ber of 



ob- 

 serva- 

 tions. 



Formulae derived sep- 

 arately for each tile 

 size. 



Revised 



intercept 



values 



m'. 



Kind. 



Nom- 

 inal 

 size. 



Actual 

 average 

 diame- 

 ter. 



Area of 

 bore. 



Hard-burned clay. 

 Do 



Indies. 

 4 

 5 

 6 

 8 

 10 

 12 

 4 

 5 

 6 

 8 

 10 

 12 



Feet. 



0. 3398 

 .4193 

 .5184 

 .685 

 .836 

 .9857 

 .3280 

 .4127 

 .495» 

 .6585 

 .8274 

 .9915 



Sq.feet. 

 0. 0907 

 .1381 

 .2111 

 .3685 

 .5489 

 .7631 

 .0845 

 .1338 

 .1940 

 .3406 

 .5377 

 .7721 



JFeet per second. 

 0.607 to 3.328... 



.634 to 4. 030... 



.765 to 3. 368... 



.893 to 4. 423... 

 1.168to5.717... 

 1.176 to 4.002... 



.504 to 3.056... 



.640 to 3. 891... 



.705 to 3.274... 



.914 to 4.959... 



.898 to 5. 486... 

 1.183 to 2.935... 



14 

 17 

 6 

 15 

 18 

 6 

 8 

 9 

 7 

 18 

 26 

 4 



s=0.0014797 V 2 -<>32fs 

 s= .0010494 V-w» 

 s= .000819 V'-fB" 

 S= .000617 yi-ww 

 s= .000384 y-9918 

 s= .0003185 V 1 - 99 " 7 

 s= .0018651 V1-85W 



s= .001077 y^ 



S= .000856 F2.0104 

 s= .0005674 V2.0373 

 s- .0005003 Fi-9632 

 s— .0003449 F2-0059 



0.0015185 

 .0010524 



Soft-burned clay. . . 

 Hard-burned clay. 



. 000761 



.0006297 



.0003927 



Do 



.0003241 





. 0017954 



Do 



.0010444 



Do 



.0008791 



Do 



.0006079 



Do 



. 0004997 



Do 



.0003546 







Since for the same kind of tile the exponents V vary for the differ- 

 ent sizes, the mean of the exponents has been taken as correct; thus, 



For clay tile, 2=1.96859. 

 For concrete tile, z=l. 96433. 



Using these mean values of z instead of the values derived for each 

 separate size of tile, new values, m', were computed for the inter- 

 cepts on the unity vertical axis, as follows: 



For clay tile, log m' =log s- 1.96859 log V (20) 



For concrete tile, log ra' =log s— 1.96433 log V (21) 



These values of m' are given in column 8 of Table 6. 



To introduce the mean hydraulic radius into the formulae, the rela- 

 tion of the values of mf to the hydraulic radii for the different sizes 

 of concrete tile is represented by the formula, 



m! = e B x 



(22) 



in which e and x are determined analytically, by a method similar to 

 that previously explained, as follows: 



Tile 



size. 



Mean 



hydraulic 



radius 



B. 



Intercept 



values 



to'. 



logiJ. 



log m'. 



Inches. 

 4 

 5 

 6 



8 

 10 

 12 



Feet. 



0.0915 



. 1154 



.1379 



.1840 

 .2316 

 .2729 



0. 0017954 

 . 0010444 

 .0008791 



.0006079 

 .0004997 

 .0003546 



Sum 



Meai 



Antilog F, 



8.961421 Sum- 27. 16319 



17.2541711 Sum= 21.217044 

 ^7.018853^Mean= 7.072348= D m ' 

 16.944020] Antilog D m '= 0.0011813 



[6.7838501 Sum= 20.032332 

 -te.6987mMean=6.677444= E m ' 

 I.6.549771J Antilog Em'= .00047582 



9.06221 lMean= 9.05439= D r - 

 9. 13956J Antilog D T = 0. 1133 . 



9.26482) Sum= 28.0655 









9.36474 lMean= 9.35519= E T . 

 9.43600J Antilog Er= 0.2265 . 



= 55.22875 



= 9.20479= F r 



= 0.1602 Antil 







Sum 



Mean 



og F m ' 



= 41.249376 



= 6.874896= F m ' 



= 0.00074971 



