No one can dispute the wisdom of the United States in deciding to build a lock canal. To have undertaken a sea-level canal would have involved this Government in difficulties so great that even with all the wealth and determination of America, failure would have ensued. It is, perhaps, putting it too strongly to say that a sea-level canal is a physical impossibility, but it is not too much to say that such a canal would take so much money and so much time to build that the resources and patience of the American people would be exhausted long before it could be made navigable.

The advocates of a sea-level canal declared that a channel could be dug through Culebra Mountain with the excavation of 110,000,000 cubic yards. As a matter of fact, Culebra Cut, with its bottom 85 feet above sea level, required the excavation of almost that same amount.

Engineers who advocated a sea-level canal declared that the material in Culebra Mountain was stable, and that only moderate slopes would be necessary. As a matter of fact, the material in the mountain proved highly unstable, and, except for a few short sections, slides and breaks were encountered all during the construction period. The result was that practically two Culebra Cuts were dug. The engineers, in beginning the present canal, calculated that 53,000,000 cubic yards would be excavated in Culebra; the amount actually removed was 105,000,000 cubic yards. Upon this basis a sea-level Culebra Cut might have required the excavation of 230,000,000 cubic yards.

Calculating an average monthly excavation of a million cubic yards, the task would have required 17 years to complete. In other words, if a sea-level canal had been undertaken and had been physically possible, the celebration of the opening of the waterway would have been set for 1925 instead of 1915.

Among all of the members of the majority of the board of consulting engineers who favored a sea-level canal, only one, E. Quellenec, Consulting Engineer of the Suez Canal, showed any appreciation of the difficulties which were to be expected in Culebra Cut. He announced, in voting in favor of a sea-level canal, that he could not do so without first reminding the United States Government of the great difficulties that would lie before it in Culebra Cut. Henry Hunter, Engineer of the Manchester Ship Canal, declared that Culebra Cut presented no serious problems at all; that a sea-level cut could be dug more quickly than the locks of the other type of canal could be built. He further declared that it was as clearly demonstrable as any engineering problem could be, that it would be possible to use 100 steam shovels in Culebra Cut. No one has accused the engineers on the canal of lack of ability in maneuvering shovels, yet at no time were they able to use more than 46.If President Roosevelt had followed the recommendation of the majority of the board of consulting engineers in favor of a sea-level canal, it seems probable that the United States would have followed the French in retiring defeated from the Isthmus, or else would have reconsidered its purpose to build a sea-level canal and have undertaken a lock canal, as the French had done.

But, even if it had been possible to build a sea-level canal at Panama, it appears that such a canal would not have been as satisfactory as the present one. While the canal the United States possesses at Panama to-day is a great waterway 300 feet wide at its narrowest part, in which ships can pass at any point, the sea-level canal projected would have been a narrow channel winding in and out among the hills, too narrow for half its length for the largest ships to pass. Currents, caused by the Chagres River, and by the flow of other streams into the canal, would have made navigation somewhat dangerous.

The principal ground upon which the majority members of the board of consulting engineers voted in favor of a sea-level canal was that it was less vulnerable. This contention, in the light of what has happened at Panama, seems to carry no great weight. Such a canal would have required a masonry dam 180 feet high across the Chagres at Gamboa, to regulate the flow of that river into the canal. This dam, very narrow and very high, would have been a much fairer mark than the great Gatun Dam for the wielder of high explosives. Furthermore, while earth dams, like that at Gatun, have weathered earthquake shocks of great severity, masonry dams, like that proposed for Gamboa, have been tumbled to the earth by shocks of much less power. The regulating works at Gatun will take care of a volume of water approximately twice as great as the Chagres has ever brought down. On the other hand, the proposed dam at Gamboa would have cared for only one-third as great a discharge as the highest known flow of the Chagres.

It was calculated that the lake made by the dam at Gamboa would always be held at low stage between floods, but if two floods came in quick succession this might have been impossible. Such a situation would have made the Chagres River always a menace to the canal, instead of its most essential and beneficent feature.

Those who objected to the lock type, on the ground that the locks could be destroyed, seemed to forget that even the sea-level project demanded a set of locks to regulate the tides of the Pacific. While, contrary to the usual idea, there is no difference in the mean level of the Atlantic and the Pacific Oceans, the difference in the tides at Panama is about 18 feet. This is due to the shape of the Bay of Panama. As the tide sweeps over the Pacific and into that bay, it meets a funnel-shaped shore line, which gradually contracts as the tide travels landward. The result is that the tide rises higher and higher until it reaches a maximum of 10 feet above average sea level. When it flows out it reaches a point 10 feet below average sea level, thus giving a tidal fluctuation of 20 feet. On the Atlantic side the tidal fluctuation is only 2 feet.

Under these conditions the canal could not be operated during many hours of the 24 without the tidal locks, if at all, and it would be almost as great a hindrance to have the tidal locks destroyed as to have the present locks injured. Another perpetual menace in a canal with a bottom width of only 150 feet for half of its distance, would be the danger of a ship sinking and blocking the channel. When the Cheatham sank in the Suez Canal it wholly blocked the waterway for nine days, and partially blocked it for a month.

According to the Isthmian Canal Commission, the present canal affords greater safety for ships and less danger of interruption to traffic by reason of its wider and deeper channels; it provides for quicker passage across the Isthmus for large ships and for heavy traffic; it is in much less danger of being damaged, and of delays to ships because of the flood waters of the Chagres; it can be enlarged more easily and much more cheaply than could a sea-level canal. The lock canal has a minimum depth of 41 feet, and less than 5 miles of it has a width as narrow as 300 feet. It can take care of 80,000,000 tons of shipping a year, and, by the expenditure of less than $25,000,000 additional, can increase this capacity by at least a third. It can pass at least 48 ships a day, doing all that a sea-level canal could do, and many things that a sea-level canal could not do.

No one denies that if it were possible to have a great Isthmian waterway at sea level as wide as the present lock canal, it would be the ideal interoceanic waterway. But, as such a proposition is out of the question, the American people have at least one thing for which to thank Theodore Roosevelt—that at a critical time in the history of the canal project he allowed himself to be converted from the advocacy of a sea-level canal to the championship of a lock-level canal, in the face of a majority report of one of the strongest boards of engineers ever assembled, and prevented a situation at Panama that would have been humiliating to America, and which probably would have ended for all time the efforts of centuries to let ships through the American Isthmus.