Clarksville weekly chronicle. (Clarksville, Tenn.) 1873-1890, 1879-03-15
Some observations AmGnt tn
WnIer-WRrkS.

! Some observations AnGnt the
Wnter-WOTks.
The report of the proceedings of the City
! Council at its meeting on Tuesday, the 18th
inst, states * follows:
| An ordinance was passed amending the
I water ordinance 50 as 10 allow the water
company to use $50 feet of eight-inch pipe,
and 1850 feet OF six-inch, and 2,64O feet of
/ IOur-lncn pipe instead OF any ten-lnch pipe
/ The effect of this will be best understood
by giving the figures of the original ordi-
nance and the amended one in parallel coll
umns:
/ 900 fl. l0-inch. $50 It. S-iuch.
I 5,2Sj #. S-inch. 1850 IT. 6-inch.
Z less fl. 6-inch. 2640 fl. 4-inch.
I 1910 II. +inch.
! 1t will be easily seen that the difference
/ between the two consists in substituting
/ $500 feet of eight-inch pipe for 900 feet of
! ten-inch pipe. The length of pipe therefore
acquired in lieu of this sacrifice OF calibre is
the difference between these two figures,
which is SO feet. Some people consider this
1 rs a gain to the city, which is a great mis-
/ take; it is a very large gain to the company
| and considerable loss 10 the city in respect
of the quantity of water 10 be supplied.
The misconception arises from a confusion
/ between linear and cubic measure. People
1 imagine that the quantity OF water carried
{ by an S-inch pipe is to that carried by a To-
/ inch pipe in the proportion of to 10, which
/ is very far wide of the truth; the volume OF
/ water carried Is in the proportion, not of
! those numbers, but of theircubes, which is
I that Of 5l2 to l,OO0. In other words, the
water moving in an S-tnch pipe at a given
velocity is very little over half that which
/ will move in I0-inch pipe at the same
/ velocity, and TO contain the same quantity
of water as the 2,GiO feet Of lO-inCh pipe, 5,l75
! feet OF S-inch pipe would be required instead
/ of the $500 feet with which the new contract
/ replaces IL.
! But il is not the actual quantity Of water
which can be contained in the pipes at q
given time which is the practical concern of
! the citizens or of the company so much as
the rate at which the water can be supplied
/ to the city. Now the substitution of S-inch
| for I0-inch pipe will Of course be in the main
| pipe, and as the carrying capacity of the
I former is but little over half that of the lat
/ ter, the rate of supply will in the same pro-
/ portion be less than it would by the original
/ contract. The gain to the company is man
fest to keep their s-inch pipe supplied and
/ to force the quantity of water which it will
carry up TO the level OF the reservoir Will
| power which the lO-inch cdlibre would have
/ demanded. The loss 10 the town viii de-
I pend on circumstances not at present
stated. II is not known what will Ee the
capacity Of the reservoir nor in fact does
/ the contract provide that there is to ba afS
| reservoir at all, and therefore no one can
state what will be the surpluSage Of water
kept on hand; but upon this depends the
efficiency of the supply for fire purposes.
/ The contract is that sufficient head OF
/ water shall be always kept on hand to throw
/ four streams of water from "a nozzle of an
/ inch and a quarter diameter over the tops OF
/ the highest houses along the track where
| the hydrants are disposed. Now, if the sur
| plusage is small, there may be kept up this
/ quantity until a fire begins, but the quantity
/ will rapidly diminish during the fire, if the
| confiagration be extensive, and soon be in
| competent to throw the water half this
height, and the city may thus pay rent for
| years for the presence Of the water unused
I filling the specified test and vet the supply
| fail them in case of an actual fire.
We cannot help thinking there fore that
the City Council have again made a bad
bargain with the company; for if the sur
| plusage is small, the S-inch main will have
more than enough TO do in keeping mp the
requisite head Of water.