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System of New Orleans

A Notable Engineering Work that is Transforming the Entire Aspect this Southern Metropolis

I

By DAY ALLEN WILLEY

THE CITY of Xew Orleans has begun a new era in its history, thanks to a public improvement which is one of the most notable of American engineering feats. As a result of this great work, the community at last stands on "dry land" for the first time since it was founded by the French pioneers. For nearly two centuries, the inhabitants of Xew Orleans have been living on the surface of a great natural sponge. Owing to the topography of the city, there is no natural drainage whatever, and the formation is such that holes dug to a depth of even two or three feet would reach the water that saturated the ground nearly to the surface. Some scientists have believed that the site of the city is a part of the "trembling prairie" which is so extensive in this portion of Louisiana.

Foundations of Mud and Water

As a result of this condition of affairs, the construction of buildings even three stories in height has been a difficult problem, as it was found to be practically impossible to secure a stable foundation for them. In consequence, the great majority of the dwellings have been erected of wood: and the comparatively few structures of brick and stone have been built with great care, to prevent their foundations from settling to such an extent as to injure or destroy the buildings. The history of the Spanish fort at Belize, which was erected near the mouth of the Mississippi river and sank almost completely out of sight, is well known. The walls of the venerable St, Louis Cathedral settled after completion so that its towers crumbled. Among the engineers who realized the problem to be solved in the construction of buildings in Xew Orleans, was General Beauregard, the architect for the Xew Orleans Custom

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of the best in the world, and, in some respects, resembles that of Paris. Figs. 2 and 3 show typical scenes during the construction of these canals.

Pumping to Higher Levels

The waterways are divided into eight groups, each being served by a set of pumps operated by electric power. In all, 26 pumps are in service, having a total discharging capacity of 7,600 cubic feet per second, with an average lift of 12 feet. They are connected by a system of wires with the generating station from which all of the power is secured. This building (Fig. 4) is 181 feet in length, 140 feet in width, and two stories high. An interior view is shown in Fig. 5. The building contains an equipment of 7 units, each consisting

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INTERIOR OF CENTRAL POWER STATION. NEW ORLEANS DRAINAGE SYSTEM. One-half of engine room is here shown.

Fig. 5.

brick arches to uphold the roadway. Considering the difficult character of the work, the svstem is considered to be one

of a steam engine direct-connected to a generator, and each unit developing 2,000 horse-power. Steam is suppliednel, to be pumped into the outlet canal and finally discharged into Lake Borgne, a large inlet from the Gulf of Mexico, 12 miles east of the city.

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FIG. ti. SUCTION BASIN AND PUMPING STATION NO. 7. PARTIALLY COMPLETED.

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FIG. 7. DISCHARGE BASIN AND PUMPING STATION NO. 7. PARTIALLY COMPLETED.

Sewerage Below Water-Level

Realizing the need of adequate sewers in connection with the drainage system, a portion of the fund which has been provided is being expended for this improvement. Only a beginning has been made; but about five miles of sewers have thus far been completed, and it is intended to have the principal streets in the 560 miles of thoroughfare that traverse New Orleans, properly sewered within the next decade. Contracts have already been let for an extensive area. Provision has also been made for an ample supply of pure water, so that the people in future will not have to depend upon wells for their supply of this necessary of life.

New Activity in Building

One of the results of the extraction of the moisture from this great "sponge" upon which the city rests, is the activity in building. Already the business section of New Orleans has undergone a remarkable transformation. Since the principal canals have been completed, it has been found possible, in these districts, to erect buildings of brick, stone, and iron, which compare favorably with those to be found in other large cities of the country; and the area of one-story and two-story buildings appears to be at an end. Contracts have recently been let for a hotel which will be twelve stories high—a remarkable altitude for a New Orleans building. Although this building will contain several thousand tons of steel, the site upon which the structure is to stand has become so firm that architects say it can be built with entire safetv and with but little difficultv.

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A Quarter-Century of American Central Station Engineering

The Marvelously Rapid Progress in Electrical Engineering which has Revolutionized Industrial Conditions

Part II.

By R. F, 5CHUCHARDT, B. S.

Testing Laboratory. Chicago Edison Company

Alternating-Current Systems

SO MUCH for the early development of the direct-current systems, of which the cities cited are characteristic examples. Let us see when the alternating current entered the field. The development of the alternating-current system in America is due largely to Mr. George Westinghouse, who, in 1885, had built at Pittsburg, Pa., an experimental plant to work out the system devised by Gaulard and Gibbs in England. The first commercial result of the Westinghouse investigations, car

ried on by Shallenberger, Stanley, and others, appeared in the plant installed at Buffalo, N. Y., in November, 1886. The following year, 65 plants, with a total capacity of 125.000 lights, were built; and the increase thereafter was rapid.

With a direct-current three-wire system using 230 volts between outside conductors, it is uneconomical to transmit current much farther than one and a-half miles, because of the prohibitively large amount of copper necessary to keep down the loss in the feeders. The resistance of a conductor varies with the

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