The fact that water now freely flows in some of these bottom stratas at a very great depth below the surface should be a sufficient answer to this question; also the fact that large streams of subterranean water frequently exists, freely flowing in large quantities in stratas of gravel and sand at great depths, in which it is supposed the weight above it would compress it.

In my own experience I have found indurated clay in the bed of the Missouri River, and underneath it I have found loose gravel, bowlders, and sand of a freely water-bearing nature, and this clay has been so hard that it has weighed as high as 120 pounds to the cubic foot; as compared with the indurated clay at Gatun it would be called rock.

As the strains on masonry dams are the subject of more or less mathematical determination, taken in connection with the experience of centuries in their construction, the assurance of their permanency is beyond question.

It is utterly impossible to make a mathematical demonstration as to the permanency of earthen dams, and the fact that a dam of earth in one locality constructed on an alluvial foundation with a freely waterbearing material underneath has stood for a few years is no evidence that an earthen dam situated in another locality on a foundation of this character will stand, as it is utterly impossible to compare the foundation conditions of the two dams, and any opinion on this point is purely a matter of conjecture.

The difference in the character of the foundations of the Gatun dam is such that there is some question as to an unequal settlement of the material of which the dam is composed; and if any part of the material should be compressed as predicted by the report of the Consulting Engineers, cracks would develop which might allow the water to permeate.

BASIS FOR MR. STEARNS'S TESTIMONY.

As I read Mr. Stearns's testimony he bases his main argument in favor of the Gatun dam on an earthen dam recently built under his control in the United States where there is no evidence that exactly the same conditions exist as at Gatun, and which dam has not yet been subject to the pressure or strains which will exist at Gatun, and which dam may properly be considered not as a demonstrated but as an experimental proposition. If the dam mentioned by Mr. Stearns had stood for one hundred years and the character of the material for the same depth was exactly similar to that of the Gatun dam, it might be possible to cite it as an argument in favor of the Gatun dam, but even then it would be of doubtful significance.

SLOPES OF THE GATUN DAM.

The slope at which it is proposed to construct the dam is liable to rapid disintegration from frequent wash on account of the heavy rainfall at that locality unless it is protected in some way.

On account of the heavy rainfall it is a most unfavorable location for the construction of earthen dams, as the material is likely to become supersaturated and be subject to surface washing, sloughing, and disintegration.

LABORATORY TESTS.

All laboratory tests regarding the filtration of water through sand or gravel, to my mind, are utterly valueless in the treatment of a question of this kind, as there can be no reasonable parallel in the conditions. It is not a question of the dam itself holding back this water, but the free flow of water in the impervious strata which is known to exist in these gorges, which it is proposed to leave at this great depth under the foundations of this dam.

THE GATUN LOCKS.

One of the great dangers of locks, particularly when three are placed in flights, is that they require continuous construction of concrete walls for approximately a mile in length and the material must be of such a uniform, homogeneous nature as to prevent unequal settlement of the locks. If the material is different in character the result would be disastrous, and this is immensely intensified by the extreme length of the large masses of concrete which would be necessary in their construction.

TIDAL LOCKS.

The necessity for tidal locks has not been demonstrated, but has simply been agreed to by the Board of Consulting Engineers as a matter of precaution as they have not been able to make any mathematical demonstration of the effect of currents of a free entrance. While I am not prepared to say that at certain stages of the tide it would not be advantageous to have locks, I have not yet been convinced in my own mind of their absolute necessity, and I have yet to see any calcu lations which demonstrate that they would be.

MAINTENANCE AND OPERATION.

I think the estimates for the maintenance of the sea-level canal are entirely too high. The amount of sediment brought into the canal depends upon the area of the surface washed and the amount of rainfall which finds its way directly into the canal, and this can be taken care of by diversion channels. The mere fact that so many million cubic yards of dirt have been excavated does not of itself increase the amount of sediment. The various benches can be properly treated and the water can be taken out laterally and turned into diversion channels or turned into basins which will take it out of the canal entirely.

PANAMA RAILROAD RATES.

Referring to Mr. Shonts's testimony that it costs $3.10 to handle freight across the Isthmus. This means 6 cents per ton per mile, and this fact itself is the strongest argument that can be made for providing the railroad with proper facilities and operating it in a proper manner. If this is done there is no reason why the rate can not be reduced to an average flat rate of $2 per ton without loss of revenue.

USE OF RAILROAD TO DIVERT COMMERCE TO PANAMA ROUTE.

It is generally admitted that during the first years of canal operation the revenue will not be sufficient to pay the operating expenses and the interest on the cost of construction, even on a 2 per cent basis. For a few years this country will be expected to carry a losing investment with the hope of large gains later on. The increase will of course be gradual, year by year, as commerce is induced to use the Panama route.

The full development of the Panama Railroad will assist in causing the more rapid approach of the time when the revenues derived from the traffic through the canal will carry the investment. Consequently, if proper facilities are provided and a low flat rate established, an increase in commerce will begin at once. Even if the facilities provided at this rate make a small loss from year to year in the operation of the railroad, if it advanced to the extent of a single year the time when the canal will pay the interest on the cost of construction and its maintenance and operating expenses, the great gain will more than make up for any slight loss of revenue in the railroad in the meantime.

CANAL DUES.

[Prepared by E. L. Corthell, C. E.]

Assuming the ordinary steamship and the ordinary rules for ascertaining net register, and considering the relations between net register tonnage and "dead weight" tonnage, one being on a basis of 100 cubic feet per ton and the other on 67 cubic feet per ton (this being the average space occupied by a ton of freight), we would have for, say, a 5,000 net register ton freight steamer the following tonnages, weights, etc. It must be borne in mind that there are several kinds of tons and tonnages:

1. "Gross register tonnage," which is all the inclosed space of the vessel, and each 100 cubic feet of this gross space is a ton.

2. "Net register tonnage," which is the cargo and passenger carrying capacity of the vessel, each ton being 100 cubic feet.

3. Dead weight tonnage," which is the whole net register space divided by 67 cubic feet for each ton, this being considered the average space occupied by average ton of freight.

4. "The charter ton," or freight ton, being 40 cubic feet.

5. "The displacement ton" equals 2,240 pounds; in metric system the weight of 1 cubic meter of distilled water equals 2,204 pounds. This is the only weight ton.

We have then for the relations and figures of the 5,000 net register ton vessel the following:

Assuming the rate of $2 per net register ton for transit dues, the

cargo carried will pay only $1.36 per ton of 2,240 pounds.

SUEZ CANAL.

[Prepared by E. L. Corthell, C. E.]

Gross tonnage passing through the Suez Canal last year was 18,000,000 tons, and the net Danube measurement was 13,000,000 tons at 74 francs per ton, or about $1.50.

The capitalization of the Suez Canal, including betterments, is now about $125,000,000, and it is understood that the canal now pays for itself every four years on the present basis of earnings.

Table of comparative distances in statute miles-Continued.

In considering the saving in the value of distances by either the Panama Railroad or the Tehuantepec route it is reasonable to take 250 miles a day as the average rate of speed of a cargo steamer and the average rate of ocean freight as approximately a dollar a ton in weight for each 1,000 miles.