The morning news. [volume] (Savannah, Ga.) 1887-1900, 1899-05-07
BARRELS OF WATER IN TREES

AT This Season Root Pressure Ia So
strong That "A Tree Might BE Made
to Compress Sufficient Air to RIM
am Engine.
New York May sit is not generally
known that many common plants. sucb az
the poplar, the abution. the tomato n,ant
may DE made to compress air in a tube
until a pressure of thirty or more pounds
to the square inch is obtained. II is
noE generally known, furthermore. that al
TINS time of the year a common tree NIGH
De made to compress air enough to RIM
an engine. Yet these facts. pbrased in
more technical language. perhaps, are
known 10 every botanIst This capacity
oil pants for generating power is the re-
suit OF what Is known as root pressure
a phenomenon which becomes manifest
mostly at this season of the wear Prof
c. c. Curtis of Columbia College has do
signed an instrument for measuring root
pressure. lie was asked to explain the
phenomenon and its cause IN the course
of his rcmarks he said:
Every spring, before the leaves have
come forth on the trees and shrubberv
every plant, every vegetable growing
thing in fact develops capacity for send
ing great quantities of moisture I'D
through the trunks and branches and ont
to the bursting buds on the ends of the
twigs. The quantity of The moisture nat
urahy depends on the size of the plant.
Barrels of water travel up the he trees
is aVi1appad nv
orchard; bucketsful ascend the saplings
and smaller quantities climb up the hush
es.
No one has yet been able to explain sat
isfactorily the force which drives Il IN
IL does not rise because of capillary al
traction. From lack OF knowledge of any
other cause, we call ID root pressure II
comprises one of the problems which bot
anlsts are constantly striving to solve. The
most remarkable part of it an is the ire
mendous power of this rising column of
water Why. We have found il even in
small plants TO attain the comparatively
great pressure of two atmospheres or near
~ thirty pounds TO the square inch In
big trees the accumulated pressure must
be immense. No one has tested big tree
although l am thinking of attempting Il
as soon as l can get the proper apparatus
We know something of the power of root
IiN'NNAN AZ SAiietit pants, from our labor
atory tests We have cut off a plant near
10 the surface of the dirt in the flower
pot, ard then attached a glass tube TO me
stump. We filled the glass tube with water
and corked IL. Yet the rising pressure from
the roots was sufficient to force the cork
from the tube. Water is uncompressihle
so the cork had to go. but if the tube had
nothing but air in IL and the cork was
secured tightly enough, the air would have
been compressed.
You could make a fountain on this
principle. You should procure an s-shaped
glass tube of small bore. This glass tube
should be secured 10 the stump of a cut
off abutilon. The joint can be made with
short piece of rubber tubing, bound with
wire. Into the neck of the tube sbould he
poured some water Some of the water
should be allowed to run over into the
part of the tube attached to the Man,
This will leave on air space between The
two portions Of water. A cork with a min
point quill run through Il, should be for9.
ed tightly into the open end of the qiass
tube. The quill should be capped with q
smaller cork. Then the root pressure
should be allowed to operate. As the