INDUSTRIAL AND ENGINEERING CHEMISTRY
PmpertieS of that soil. Among thesa cbangee s;ya an iliqresm in exchange capsoity (4) and a lowering of the pH at which iron and duminum come into solution. Any inin exchange capacity d t a in a -tar retention of the nutrient cations which will have been applied in oombination or in association with tbe phwphate. The downward shift in pH at which the iron and duminum come into solution m a y be 88 much 88 0.5. Theaa facte help explain why it is @le to continue producing bigh yields of potatma on soils which must be maintained at pH vsluas approximating 5.2 for the c o n t d ofsaab. The potato farmer accompliahea hi^ immediate purpose by wing bbably twica 88 much phoephste a~ would be raquired on aoiLe of pH 6.6, Ultimately he may develop a bigh-pbwphate soil, having a relatidy high exchange eapacity and B relatively low content of soluble ir0n and duminum for ita pH. An ides of the d b l e effect of the long-continued w of large amounta of soluble phospaste in incmwing tbe exchange capacity of soils is obtained fmm Table V.
End of
.. 0.0 0.4 0.6
0.55 0.82
1.0.
o.n
0.9
0.65
0.m
VoL34,No.l
... 60
70 1W 151
Symposium
~~
Nomograph for Flow from Partially Filled Pipes D. S. DAWS W a p e UnirSnity, Detroit, Mieh.
REvE1 G . filled
proposed an qua-
tioq for flow in partislly
---
horizontal pipes, Q 9.48 Z P W K1.u w h Q rata af flow oubiofeet D K
-
per e n d inner &meterof ipe, fwt (limited toi.10.6 foot
fraction of vertical diameter under 0uid (limited to 0.2-0.8)
The method of measuring tlow is simple, inexpensive, and =tisfaotory for rough e&.u~~tions gocdtosbout10perEent. The nemogrsph which facilitatenthe dculation is lwsed on the equiv& lent equation:
--
p
where q d
7.8 d1.U g l . 8 ,
r8ta.d How, gauonS per
rmntlte inner diamaqu of pipe aO-kta2-8 @ch standard iron pips
The index h e
& o m that
24
om per minute flow through
a horizontal %inch 8tsndard iron pipe when 0.4 of the inner vertid diameter is under the fluid. Bull. R v l u a Unb.. IS, Ne. 6 (1928). Bull. 8%
,
