The Progress of the Century

by Unknown

HYDRAULIC ENGINEERING

This is one of the oldest branches of engineering, and was developed before the last century. The irrigation works of Asia, Africa, Spain, Italy, the Roman aqueducts, and the canals of Europe, are examples. Hydraulic works cannot be constructed in ignorance of the laws which govern the flow of water. The action of water is relentless, as ruined canals, obstructed rivers, and washed-out dams testify.

The principal additions of the nineteenth century to hydraulic engineering are the collection of larger statistics of the flow of water in pipes and channels, of rainfall, run-off, and available supply. It is now known that the germs of disease can be retained by ordinary sand filters, and it is now an established fact that pure drinking water and proper drainage are a sure preventive of typhoid and similar fevers. Very foul water can be made potable. Experiments show that the water of the Schuylkill River at Philadelphia, which contains 400,000 germs in the space of less than a cubic inch, was so much purified by filtering that only sixty remained. This is a discovery of sanitary science, but the application of it is through structural engineering, which designs and executes the filter beds with great economy.

The removal of sewage, after having been done by the Etruscans before the foundation of Rome, became a lost art during the dirty Dark Ages, when filth and piety were deemed to be connected in some mysterious way. It was reserved for good John Wesley to point out that “Cleanliness is next to godliness.” Now sewage works are as common as those for water supply. Some of them have been of great size and cost. Such are the drainage works of London, Paris, Berlin, Boston, Chicago, and New Orleans. A very difficult work was the drainage of the City of Mexico, which is in a valley surrounded by mountains, and elevated only four to five feet above a lake having no outlet. Attempts to drain the lake had been made in vain for six hundred years. It has lately been accomplished by a tunnel six miles long through the mountains, and a canal of over thirty miles, the whole work costing some $20,000,000.

The drainage of Chicago by locks and canal into the Illinois River has cost some $35,000,000, and is well worth its cost.

Scientific research has been applied to the designing of high masonry and concrete dams, and we know now that no well-designed dam on a good foundation should fail. The dams now building across the Nile by order of the British government will create the largest artificial lakes in the world. The water thus stored will be of inestimable value in irrigating the crops of Lower Egypt. Their cost, although great, will not exceed the sums spent by the lavish Khedive Ismail on useless palaces, now falling to decay.

The Suez Canal is one of the largest hydraulic works of the last century, and is a notable instance of the displacement of hand labor by the use of machinery. Ismail began by impressing a large part of the peasant population of Egypt, just as Rameses had done over 3000 years before. These unfortunate people were set to dig the sand with rude hoes, and carry it away in baskets on their heads. They died by thousands for want of water and proper food. At last the French engineers persuaded the Khedive to let them introduce steam dredging machinery. A light railway was laid to supply provisions, and a small ditch dug to bring pure water. The number of men employed fell to one-fourth. Machinery did the rest. But for this the canal would never have been finished.

The Panama Canal now uses the best modern machinery, and the Nicaragua Canal, if built, will apply still better methods, developed on the Chicago drainage canal, where material was handled at a less cost than has ever been done before.

Russia is better supplied with internal waterways than any other country. Her rivers rise near each other, and have long been connected by canals. It is stated that she has over 60,000 miles of internal navigation, and is now preparing the construction of canals to connect the Caspian with the Baltic Sea.

The Erie Canal was one of very small cost, but its influence has been surpassed by none. The “winning of the West” was hastened many years by the construction of this work in the first quarter of the century. Two horses were just able to draw a ton of goods at the speed of two miles an hour over the wretched roads of those days. When the canal was made these two horses could draw a boat carrying 150 tons four miles an hour. Mud, or, in other words, friction, is the great enemy of civilization, and canals were the first things to diminish it, and after that railways.

The Erie Canal was made by engineers, but it had to make its own engineers first, as there were none available in this country at that time. These self-taught men, some of them land surveyors and others lawyers, showed themselves the equals of the Englishmen Brindley and Smeaton, when they located a water route through the wilderness, having a uniform descent from Lake Erie to the Hudson, and which would have been so built if there had been enough money.

The question now is whether to enlarge the capacity of this canal by enlarging its prism and locks, or to increase speed and move more boats in a season by electrical appliances. The last method seems more in line with those of the present day.

There should be a waterway from the Hudson to Lake Erie large enough for vessels able to navigate the lakes and the ocean. A draft of twenty-one feet can be had at a cost estimated at $200,000,000.

The deepening of the Chicago drainage canal to the Mississippi River, and the deepening of the Mississippi itself to the Gulf of Mexico, is a logical sequence of the first project. The Nicaragua Canal would then form one part of a great line of navigation, by which the products of the interior of the continent could reach either the Atlantic or Pacific Ocean.

The cost would be small compared with the resulting benefits, and some day this navigation will be built by the government of the United States.

The deepening of the Southwest Pass of the Mississippi River from six to thirty feet by James B. Eads was a great engineering achievement. It was the first application of the jetty system on a large scale. This is merely confining the flow of a river, and thus increasing its velocity so that it secures a deeper channel for itself.

The improvement of harbors follows closely the increased size of ocean and lake vessels. The approach to New York harbor is now being deepened to forty feet, a thing impossible to be done without the largest application of steam machinery in a suction dredge boat.

The great increase of urban population, due to steam and electric railways, has made works of water supply and drainage necessary everywhere. Some of these are on a very grand scale. An illustration of this is the Croton Aqueduct of New York as it now is, and as it will be hereafter.

This work was thought by its designers to be on a scale large enough to last for all time. It is now less than sixty years old, and the population of New York will soon be too large to be supplied by it.

It is able to supply 250,000,000 to 300,000,000 gallons daily, and its cost, when the Cornell dam and Jerome Park reservoir are finished, will be a little over $92,000,000.

It is now suggested to store water in the Adirondack Mountains, 203 miles away, by dams built at the outlet of ten or twelve lakes. This will equalize the flow of the Hudson River so as to give 3,000,000,000 to 4,000,000,000 gallons daily. It is then proposed to pump 1,000,000,000 gallons daily from the Hudson River at Poughkeepsie, sixty miles away, to a height sufficient to supply the city by gravity through an aqueduct. This water would be filtered at Poughkeepsie, and we now know that all impurities can be removed.

If this scheme is carried out, the total supply will be about 1,300,000,000 gallons daily, or enough for a population of from 12,000,000 to 13,000,000 persons. By putting in more pumps, filter-beds, and conduits, this supply can be increased forty per cent., or to 1,800,000,000 gallons daily. This water would fill every day a lake one mile square by ten feet deep. This is a fair example of the scale of the engineering works of the nineteenth and twentieth centuries.

By the application of modern labor-saving machinery, the cost of this work can be so far controlled that the cost to the city of New York per 1,000,000 gallons would be no greater than that of the present Croton supply.

All works of hydraulic engineers depend on water. But what will happen if the water all dries up? India, China, Spain, Turkey, and Syria have suffered from droughts, caused clearly by the destruction of their forests. The demand for paper to print books and newspapers upon, and for other purposes, is fast converting our forests into pulp. We cannot even say, “After us the deluge,” for it will seldom rain in those evil days. When the rains do come, the sponge-like vegetation of the forests being gone, the streams will be torrents at one time of the year and dried up during the rest, as we now see in the arid regions of the West.