REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL.


complement, it can be demonstrated that as much as 20,000,000 cubic yards of material classed as rock may be annually removed from the summit cut. This estimate is based upon an average number of working days of not more than 20 per month throughout the year, which is an underestimate on the b-asis of the experience of the French companies and of that which has accrued since American occupation began, in May, 1904. In this estimate the capacity of one shovel is taken as materially less than would be justified by the actual operations of steam shovels in the Culebra cut during the past year, both in wet and dry seasons. Furthermore, it has been supposed that the working day is to be but eight hours long and that one shift only of laborers would be employed per day, whereas it is perfectly feasible to work two shifts in twenty-four hours during the greater part of the year and possibly during the entire year. Using these estimates for the period of what may be assumed to be the maximum annual output in the Culebra cut, and allowing at least two and a half years to attain this maximum rate at the beginning of the work and a period of not less than three years for a decreasing output in the more contracted space in the lower portions of the cut during the closing period of operations, it is found that the entire quantity of 110,000,000 cubic yards of material in the divide can be removed within ten years. (For time curve illustrating practicable excavation of Culebra cut, see Plate XXXI.)
 Although the preceding estimate of time has been based upon ample allowances for the effect of the rainy seasons, for the low grade of labor available on the Isthmus, and for climatic conditions in general, the Board has added about 25 per cent to it for other contingent causes of delay, either similar to those already provided for or of any other character. It is therefore the judgment of the Board that a ship canal on the sea-level plan outlined in this report can be completed within a period of time not exceeding twelve or thirteen years.

 (F) IMPORTANT CONSIDERATIONS.

 A map of the world or, still better, an ordinary terrestrial globe presents at a glance the reason for the construction of the Panama Canal, such map or globe being of itself sufficient to indicate what the status kf' the waterway will be, and to show that the canal will provide the one great maritime highway of the West-not between seas, but between oceans; not for countries, but for continents.
 The vastness ofte interests to be served by the canal, many of which interests now wait for their development on e construction of the waterway, demands that the canal shall, when opened for traffic, be of the type which will most perfectly fulfill the purposes which the waterway is intended to accomplish.
 First and foremost it is essential that the Panama Canal shall present not merely a means of interoceanic navigation-it may be said that any type of canal would enable vessels to pass from ocean to ocean-but a means of safe and uninterrupted navigation, on which no special hazards will be encountered by and no vexatious delays will be occasioned to the vessels which will traverse it. It is therefore evident that the canal ought to be formed in such manner that the course thereof shall be free from all unnecessary obstructions, and that no obstacles should be interposed in that course, whether temporary or permanent, which would by their very nature be an occasion of peril and of detention to passing vessels, and more particularly to vessels of the great size which the Panama Canal is (in accordance with the provisions of the law of Congress) designed to accommodate.
 The Board is of opinion that this consideration should be of determinative force in respect to the type of canal to be adopted, and that it should lead to rejection of all proposed plans in which lift locks, whether few or many, form the principal or dominating features, and consequently to the acceptance of the sea-level plan as the only one giving reasonable assurance of safe and uninterrupted navigation.
 It is not suggested that a maritime canal with locks forming the essential feature is an inherently unsafe system of navigation, for experience has not only demonstrated the contrary, but also that the matter is one of degree. A navigation with locks of small size capable of passing the ordinary commercial steamers may be made reasonably safe, while a maritime waterway with locks of the dimensions which the Board has considered to be necessary in order to


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