C

ONSTANT repetition often gives to a statement weight and authority which

it by no means deserves. So long have we been assured that smoking factory chimneys mean prosperity that we have come to consider a smoke-filled atmosphere as synonymous with a full pocketbook. Now comes the University of Pittsburgh, after an exhaustive smoke inquiry, assuring us that smoking factory chimneys, far from being a sign of prosperity, are the emblem of waste; that a smoky sky, instead of filling our pockets, puts a steady drain on them. So enormous, in fact, is the waste caused by smoking factory chimneys, that our economic loss from this cause alone annually far exceeds the entire cost of the Panama Canal.

Smoke is waste. Black smoke consists largely of unconsumed coal particles thrown into the atmosphere by improper stoking. Investigating every type of hand-stoked and machine-fed furnace, the Pittsburgh investigators found that the loss up the stack is fully twenty-five per cent. By careful stoking, 3.6 pounds of coal can be made to do the work ordinarily accomplished by 4.6 pounds. This means a saving of 21.7 per cent of the present fuel consumption. In the Pittsburgh district 16,000,000 tons of coal, worth $20,000,000, are used annually. The portion of this coal thrown away in smoke is estimated by Mr. J. J. O'Connor, Jr., the economist for the investigating staff, to be. worth $4,340,000.

Aside from its coal content, smoke contains acids of value. These can be isolated in commercial forms. Usually they are thrown away. It is estimated that the smelters near Salt Lake City daily throw away in smoke acids worth $10,000. .

The acids in smoke include sulphuric acid, sulphurous acid, hydrochloric acid, ammonia compounds, etc. A large part of these acids is contained in the soot and the tar of smoke. The soot absorbs them, and the tar, mixing with it, sticks it fast to everything it touches. Thus held in close contact, the acids of smoke work destruction on everything they touch. Rain and air make them more actively destructive. Thus the comparatively harmless sulphurous acid is rapidly changed by the oxygen of the air into the far more corrosive sulphuric acid. The acids held by the soot

and tar do much more damage than those which escape into the air. Where metals are concerned galvanic action is likely to be set up. Neither rainfall nor wind can sweep away the soot held by tar. So the destructive acids are held fast where they can do most harm. By our reckless carelessness with our furnaces we send up day and night clouds that later return to plague us.

Gravity brings the heavier particles to earth, and the rainfall washes the skies of the lighter particles. The amount of soot and tar thus brought to earth is incredible. In the center of London the annual soot deposit equals 426 tons to the square mile, with 539 tons in Leeds, while in Glasgow the yearly rate of deposit per square mile amounts to 820 tons. The combustion of coal in the British Isles produces about 3,000,000 tons of sulphuric acid annually. The sulphur content of the smoke given off by Pittsburgh furnaces alone is estimated at 500,000 tons a year.

With this acid-filled smoke glued fast to everything it touches, it can easily be seen that the resulting damage is enormous. Building materials of all kinds are harmed by smoke. Metals are corroded and tarnished. Metal roofs are eaten away. In some cases structural ironwork has been so corroded as to endanger an entire structure. If all the acid yearly poured forth by Pittsburgh chimneys were to act upon structural iron, it could dissolve completely 265,000 tons and render useless many tons more. The corrosion of either protected or unprotected ironwork is much more rapid in smoky cities than in the country. Experiments made in England show that unprotected iron corrodes six times as rapidly in town air as in the pure air of the country.

Zinc is affected by even the most dilute acids. Tin is little affected. Copper is slightly harmed by sulphur acids, and copper and brass are particularly sensitive to hydrogen sulphide. This is well shown by the familiar blackening of copper and brass signs, which necessitates constant polishing. Hydrogen sulphide blackens silver. A piece of metallic aluminum one-sixteenth of an inch thick was completely corroded away by three years of exposure to Pittsburgh air. The life of all metals is found to be much shorter in

Pittsburgh than in smoke-free cities like Washington. Metals must be painted twice. as often in Pittsburgh as in a smoke-free city, and removed in one-half the length of time. Building stones, like iron, are disintegrated by smoke. Commonly we think of smoke as working only an æsthetic damage to stone structures and even that is no trifle. smoke works far more harm than this. causes stone to crumble. Pittsburgh's sootfall varies in different parts of the city from 595 to 1,950 tons per square mile a year. If an amount of lampblack equal to the larger soot-fall were ground with oil so as to form black paint, it would cover fifty-seven square miles of surface with two coats. The destructive possibilities of Pittsburgh's soot-fall thus become evident. Stuck fast by tar, and indissoluble by rainfall, this soot can be removed only by drastic measures, such as scouring, the use of solvents, or the sand blast. be rentable buildings must be kept clean and attractive. The cost of keeping them clean places a heavy tax upon property-owners, and this tax, like the cost to the manufacturers for the smoke that produced it, is passed along to the public by means of higher prices.

The acids contained in soot injure building stones just as they harm metals. The sulphuric acid contained in the smoke of Pittsburgh is sufficient, if allowed to act on limestone, to destroy 500,000 tons of that material. Limestones, dolomite, and sandstones with a calcareous cementing material are directly disintegrated by smoke. Granite, gneiss, and sandstones held together by some cementing substance other than a carbonate are but little corroded by smoke. But these stones are costly and difficult to handle. They are readily soiled, and when finished in the rough are extremely difficult to clean. Nothing, short of a scouring with acids or the sand blast will clean them. Either of these operations is harmful to stone. The protecting crust formed by nature on the exterior of the stones is worn away and the stone begins to crumble. On stones of the limestone group the acids of combustion act directly, disintegrating them badly. In many

of the older buildings in Pittsburgh the smoke has eaten out the mortar to a depth of onethird to two-fifths of an inch.

In England and elsewhere abroad the preservation of ancient stone buildings has become

a serious problem. One of Great Britain's historic old buildings has become so soft that the mere rubbing of the surface will remove a quarter of an inch of decayed stone. Chemical analysis of this stone shows that this decay is due to the action of sulphur acids in the air.

Interior decorations and construction materials suffer equally. Wall paper, paint, hangings, and furnishings of all kinds must be renewed and cleaned perhaps twice as often as is necessary in clean cities. To keep his linen clean costs a Pittsburgher $3.12, where it costs a Bostonian $2.35, and a resident of Washington $2.40.

Again, the smoke pall shuts out a large part of the sunlight. The smoke-free city of Los Angeles receives 60 to 75 per cent of the possible sunshine. Pittsburgh gets only 38 to 58 per cent. This deficiency must be made up by the use of artificial light. All these things lay a heavy tax upon the individual pocketbook.

But the most serious loss we suffer from smoke is the damage done to the health and spirits of our people. Fogs, dark, cloudy days, decreased hours of sunshine, all are

specific diseases as bronchitis, pneumonia, and subacute forms of phthisis, but the poisonous compounds also enter the gastrointestinal tract, and this causes nausea, vomiting, diarrhoea, and systematic poisoning."

This statement, in the light of experiments made by Saito, is easily credible. Saito caused a man to inhale white-lead dust for from ten to fifteen minutes on twenty different occasions, and to avoid swallowing during the experiments. Of the dust thus inhaled 95 per cent remained in the body of the subject, half of which was retained in the nasal passages, while 12 per cent probably found its way to the lungs.

What, then, must be the condition of persons who constantly breathe smoke-laden air? The weight of the solid matter in the smoky air of Leeds has been found to be 200 pounds per square mile, while the dust particles vary in number from 530,000 to 3,736,000 per cubic inch. A large percentage of these particles consists of smoke and soot. Dense though the atmosphere of Leeds is, that of Pittsburgh is in places nearly three times as dense. In consequence, innumerable poisonous and irritating particles get into the mouth, nose, and lungs of every one who breathes the air. In the lungs of a Pittsburgh street peddler 10.6 grams of such foreign substances were found.

Persons whose lungs are thus irritated readily fall a prey to pulmonary diseases. Singers on visiting Pittsburgh usually get 'Pittsburgh sore throat." The writer knows a traveler who, visiting Salt Lake City at one of those periods when the city is buried in smelter smoke, contracted a serious laryngeal trouble and even completely lost his voice during a stay of one week in that city. The attending physician said the affection was due to smoke. One of the conspicuously serious facts established by the Pittsburgh smoke investigation is the virulency of acute lung diseases in smoke-infested atmospheres. While the course of chronic lung diseases, like tuberculosis, appears not to be hastened by smoke, acute diseases, like pneumonia, carry off their victims in smoky neighborhoods. with frightful rapidity.

Finkelburg has shown that in England the mortality from affections of the bronchial tubes is more than half as great again in towns as in the country, and that it rises to an unusual height in places where coal is much used. In Germany the mortality from acute pulmonary diseases has increased, and

the course of pulmonary tuberculosis has been accelerated, as the country becomes more industrial. The increase in non-tubercular lung mortality has amounted to 30 per cent in the smoky town of Waldenburg as compared with the near-by smokeless town of Wusterwaltersdorf. The death rate per ten thousand for the same diseases is 30.6 in the non-smoky city of Hamm, as compared with a rate of 57.4 for the smoky city of Gelserkirchen. In all German towns with a population of more than 15,000 the death rate is 24, while in the smoky industrial centers of similar size in Rhenish Westphalia it is 34, and in the industrial districts in upper Silesia it is 36. In rural districts in England it is 17.5, compared with 26.5 in urban industrial districts. Dr. W. C. White's investigation shows that in Pittsburgh pneumonia increases with the density of atmospheric smoke, irrespective of poverty or the density of population.

Similar facts have been set forth by Dr. Ascher, of Koenigsberg. He found also that animals that had inhaled smoke developed pneumonia more easily than animals that had not inhaled smoke. Likewise he has demonstrated that tuberculous patients, both male and -female, die at an earlier age than formerly. Of every one hundred persons dying of tuberculosis in Prussia in 1876, 36 males and 32 females were more than fifty years of age. In 1901 only 28 tuberculous males and 23 females survived the age of fifty. This means that, though the death rate for tuberculosis may not be on the increase, in smoky districts the disease runs its fatal course in shorter time. In our own country, because of the persistent war we wage on tuberculosis, the death rate from that disease is slowly decreasing. But if Dr. Ascher's findings hold true in our own country, our tubercular population, though not increasing in number, is dying at an earlier age.

Our pneumonia death rate, however, shows an appalling increase. In 1900 the pneumonia death toll was 105,971; for 1909 it was 122,400; and for 1910 it was 136,000an increase of ten per cent in one year. Dr. Ascher's statistics also show that since 1875 the number of infant deaths from pneumonia has increased six hundred per cent. These increased death rates are largely attributable to the growing smokiness of our atmosphere.

Even where death does not ensue from dwelling in a smoky region, there can be no doubt that much of human energy and hap