116 DOCUMENTARY HISTORY OF THE FLORIDA CANAL

which have been used by the board in making up its estimates. In addition to
this, the board has established slopes and a width of berm which are un-
necessary and which very materially increase the yardage to be excavated and
the unit costs of excavation. It can be shown that there is no considerable
quantity of material to be excavated which cannot be economically removed by
adequately designed and constructed hydraulic dredges, of the cutter type,
supplemented by mining where this would increase the economy of the opera-
tion. If the canal is dug in this manner, it can be shown that its cost can be
reduced to approximately $124,000,000.
 REVENUES FROM TOLLS

 To gain a clear idea of the unnecessarily wide margins of safety used by
 the special board of review in estimating revenues, it is necessary to inspect in
 some detail the elements upon which all such estimates are based. These are:
 1. The number of vessels which will transit the canal, divided into two
 general classes:
 (a) General passenger and cargo carriers.
 (b) Oil tankers.
 2. The savings which will accrue to vessels when using the canal, divided
 into three classes:
 (a) Savings in operating costs.
 (b) Savings in fixed charges.
 (o) Savings accruing by reason of the greater number of voyages made
 possible by the shorter route.
 The Corps of Engineers, the engineers of the Public Works Administration,
 and the special board of review substantially agree that the total number of
 vessels which might profitably transit the canal annually at the time of its
 opening in 1941 will be approximately 12,500. The Corps of Engineers and
 the engineers of the Public Works Administration agree that this traffic will
 show a gradual increase from year to year for an indefinite period. The fact
 that the petroleum reserves of the Gulf and Valley States must be gradually
 exhausted, and that shipments of this material from Gulf ports will con-
 sequently diminish, was known to and undoubtedly considered by them. The
 special board of review, in its supplemental report, assumes that the diminution
 of petroleum shipments from the Gulf ports will result in such a decrease in the
 total water-bourne commerce into and out of the Gulf as to show, instead of a
 gradually rising trend, a rather sharply decreasing trend for the next 70 years.
 This assumption is so contrary to experience and to the probabilities that it
 must be judged to be gravely in error.
 The movement of petroleum depends upon the utilization of the Internal-com-
 bustion engine, upon which our mechanical and industrial civilization is based.
 To assume that the movement of petroleum (or some liquid fuel) will cease or
 sharply diminish is to assume a sharp diminution in the use of this form of
 power. The growth and development of the Gulf and Valley States depend
 largely, not only on the continued use of existing internal-combustion equip-
 ment, but upon the steady increase of this. Liquid fuel, whether petroleum,
 benzol, alcohol, or some synthetic product, must continue to be moved to these
 engines. All experience in the movement of vital basic commodities indicates
 that long before the exhaustion of the petroleum reserves in the Gulf and
 Valley States, petroleum (or its equivalent) will begin to be imported into the
 Gulf ports; the point of balance being determined by economy. As the petro-
 leum reserves even remotely approach exhaustion, Importations will necessarily
 increase. In other words, the more probable projection of water-borne petro-
 leum or other internal-combustion engine fuel out of and into the Gulf, will
 show gradually decreasing exports and gradually increasing imports, with the
 average total of both over thb next 50 years probably not less than the present
 volume of exports alone. This, coupled with an undisputed increase in gen-
 eral cargo movement, will yield a total water-borne commerce increasing year
 by year for an indefinite period. It must be evident that regardless of other
 factors entering into estimated revenues of the canal, this factor of an increas-
 ing, rather than a diminishing, traffic, is preponderant, and that if it is shown
 that the initial volume of traffic available to the canal is maintained or gradu-
 ally increased, the entire picture presented by the special board of review's
 findings with regard to revenue will be materially changed to the benefit of the
 project