Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-02-02

Several of the large rubber manufac-h
turing companies have facilities to make
rubber blocks and one company in
Racine, Wis, specializes in their man
ufacture. The machinery necessary in
the manufacture is relatively simple.
and obviously somewhat lower grade
of rubber can be introduced into the
blocks than that used in the better
types of automobile tires and In fine
rubber goods,
In addition to the diminution Of noise.
rubber-block paving is said by the De-
partment of Commerce to possess other
advantages. From the point of view
of the daily interest of the general pub
lie, one of the chief of these is that
this paving is dustless. 40
From the engineering point Of view
one of the most important advantages
is that roadway paved with rubber
does not vibrate. These advantages
come into play principally in connee-
ton with bridges. The constant VI
bration set up by traffic rolling along
streets and over bridges paved with
the usual materials is so great that
bridge structures are endangered. Since
the introduction of the automobile,
many bridges which were entirely ade-
quate formerly have had to be strength
ened, not because of heavier load but
! because of the vibration set up by the
| steady throbbing of innumerable en-
| g1nes. In building new bridges en-
| gineers now take this vibration into ac-
count and allow larger co-efncient Of
safety. Rubber paving, used as a sur
| face for such bridges absorbs this VII
bration and goes far toward solving the
problems 1t presents.
Price Remains Big Factor.
The big factor, however, is the mat
ter of price. Rubber Is product found
only in certain restricted areas of the
| world. 1t has, In the past, been sub
| 1ect TO astonishing fluctuations in price.
! The price range of crude rubber during
the last decade has been from Is cents
| 10 $l.21 pound. This has been due
| to artificial governmental controls set
up and to variations in production.
NOW suppose city council votes an
appropriation to pave a city street with
rubber blocks. Estimates have been
made and. perhaps, tentative bids re-
celved. The paving Is laid down at the
Time rubber was selling, let us say, at
~ cents a pound. Some time later it
becomes necessary to make repairs and
renewals or to extend the paved mile
| age with the same material It is dis
covered that the price of rubber has
SCARED to rs cents a pound. It will
readily be seen that any city budget
maker would be likely to have night
mares under such working conditions.
However. there is reason to believe
that the days of wide fluctuations In
the price Of rubber are past. For the
last year the price of crude rubber has
been more nearly stable than 1t has in
any year since the war. In spite of the
| fact that consumption for automobile
tires and other uses has steadily In
creased in volume there has been no
rise in price. Production and consunnp-
ton seem to have reached a stable
balance, both gaining steadily. In about
10 years big change is likely to occur
when the tremendous rubber plantation
project in the Amazon Basin comes into
bearing. At that time it is likely the
price will drop. In fact in all probabili-
ty, as the time approaches for the Bra
lillian rubber to come on to the mar
ket, the new supply will be discounted
| and prices will trend downward in an
ticipation -