In reviewing the progress of concrete in the Northwest, Mr. L. B. Roberts shows both a com prehensive grasp of present conditions and a prophetic insight into the future when he says: "The new San Francisco is rising Phoenix-like out of the ashes of the old, a city of concrete. She is guarding the western portal of the nation against the dread bubonic plague, with Portland cement as her physician, and con crete her disinfectant. In a war of extermination against the rat and its flea, the prime carrier of disease, millions of yards of concrete have been laid. Wooden sidewalks, alley-ways, gutters, piers, and buildings are being torn down and replaced with concrete, disease and vermin proof, under the supervision of United States engineers. And with the advent of the era of cement, the mortality rate in that city alone has decreased 50 per cent.
"The same precaution must in time be taken in New York, Savannah, Baltimore, and other ports of entry, as the plague seems to be slowly creeping northward, and with the completion of the Panama canal, the liability of seaports to infection will be increased two-fold.
"Portland cement made it possible to reconstruct the new Galveston on a grade many feet higher than the old city. Millions of barrels of it will figure in the Pan ama canal work alone, and the use of this material made possible New York City's splendid system of subways. London relies on it to regain some of her prestige as a seaport she has lost to Liverpool and Glasgow, and has ordered in new piers of reinforced concrete all along the Thames.
"It is almost the sole building material used in the vast government reclamation projects in the arid West.
"Its cheapness, its beauty when finished, and its dura bility constantly recommend it to the thoughtful house holder seeking to build a home and to gain the maximum of durability with the minimum of cost. Houses of con crete, at half the cost of a wooden dwelling, are a promise of the very near future, according to the results of experi ments made by Edison and others.
"Ships of reinforced concrete, and Dreadnoughts pro tected with•belt armor of concrete and steel, are a very real possibility of the future. Already canal boats have been made of concrete on a small scale, by a Missouri firm, and have been found to be perfectly satisfactory. Similar experiments are being made by the Italian Gov ernment. Experiments have been made with a belt armor made of reinforced concrete faced with steel, which indi cate that it may prove a greater resistant to the impact of a projectile than even steel itself.
"Especially on the farm is Portland cement coming into more and more common use. With the increasing price of lumber, the farmer finds he can floor cow-barns, erect silos, and do other similar work more easily and more cheaply with Portland cement than with any other material. . . .
"It has even entered the field of the fine arts. White Portland cement, pure as the driven snow and white as the purest of Parian marble, at the same time possessing the strength and adamantine hardness of the gray cement, is a discovery of the past year (1908). It retains the finest impression from the mould, as faithfully as wax, and outlasts marble in the struggle with time and the elements. It promises largely to supplant decorative stone for the trimming of buildings, to take the place of plaster of Paris for the decoration of theaters ; and rep licas of the world's most famous statues will be seen in the parks and on the driveways of the future, perpetu ated in a material which will outlast the blocks of solid stone given form by the cunning hand of the sculptor.. . "It is already the favorite building material on the plains of the Dakotas and Montana, where lumber is rela tively scarce and prices high; and in the new boom towns, high schools, libraries, and public buildings are largely constructed of it.
"It is already looked on as the natural successor to lumber, and some there are who see in it the solution to some of the forestation problems. With the invention of steel moulds, the use of lumber even in forms for the concrete may be done away with.
"The future of the industry is assured. The exhaus tion of raw material is so remote a possibility that it may be dispensed with. Limestones, clays, shales, and slate are found in large quantities in most of the States of the Union. Throughout New York, Pennsylvania, and most of the Eastern and Southern States, these minerals exist in inexhaustible quantities in close juxtaposition; while the south shore of the Great Lakes, especially through Ohio, Indiana, Illinois, and Michigan, is almost solidly underlain with limestone. Coal and labor are easily available in these districts as well, which accounts for the large production of Portland cement in these regions. The greater part of the country's output is produced in these States, though smaller plants are scat tered about through the South and Middle West and the Coast States. . . .
"Throughout the Northwest, Portland cement is com ing more and more into use for buildings, sidewalks, dams, railroad construction, and use in every shape and form. Already it has assumed a place of prime impor tance•in building circles, and is increasing in importance day by day and year by year. Truly the era of cement has but begun—its future is assured."