Popular Science Monihly
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��civic pride and for the general good. All of this was done without legal process or application in any way to the courts, ahhough the Bureau was em- powered to act against \i()lators. The next year, twenty thousand "eleaning- up" cards were distributed witii ijood effect. They contained the Ringleniann scale for smoke density adopted by the Ignited States Government Bureau of Mines — inch squares checked off in one hundred spaces by light, dark, dense and black lines, representing densities of twenty, forty, sixty and eighty per cent — the third, or sixty per cent, being the legal maximum. The Pittsburgh Chamber of Commerce endorsed the work of the Bureau.
Conferences with railroad operating officials and manufacturers enabled the Bureau to suggest smoke abatement appliances especially fitted for each plant. The widest publicity was given the campaign by local newspapers and there were few stacks in the city that did not have their smoke output closely watched. Improvements had to be licensed by the Bureau, so that only practical appliances were permitted. Hundreds of concerns subsequently re- ported to the Bureau that the smoke abatement crusade had benefited them by helping to reduce their coal con- sumption and lessening operating costs.
The beneficial results of the smoke aliatement propaganda ■ have » been widespread. Fully ninety-nine per cent of the locomotives in Pittsburgh yards arc now compKing with the law,
��The small particles of carbon which escape in the form of smoke are only a small part of the loss in the heating value of coal, for the loss due to the escape of combustible gases is ten or more times the carbon loss. The smoke escaping from the engine is Pittsburgh's legal maximum
��the number involved being eleven hun- dred and ninety daily. Before the campaign, only one per cent com[)licd with the law.
Even to strangers in the city, the smoke abatement is very noticeable in Piltsliurgh. The atmosphere is practi cally free from soot particles in the downtown section in particular. Fogs are disspelled by the middle of the day and frequently by the middle of the morning, whereas formerly the city was in a pall for at least a day, and sometimes longer. The Pittsburgh weather Bureau local office announced that the periods of "dense smoke" last year were less than one half those of 1913, despite the fact that at least two and a half times as much coal was consumed. The Bureau of Smoke Regulation has calculated that the annual saving to the people of Pittsburgh, through the reduction in the quantity of smoke cannot be estimated at less than two million five hundred thousand dollars.
The proper way to read smoke densi- ties from the Ringlemann chart is as follows: The chart is placed in line with the top of a stack a sufficient distance from the eyes so that the lines are not visible (about ten feet) and the smoke emitting from the stack is then compared with the different scales on the chart. This enables every factory manager and fireman to be his own smoke inspector and determine at all times if the smoke ordinance is being violated. In Cincin- nati any smokeof greaterdensity than the sixty percent scale violates the ordinance.
