Almost every industrial town or city in the United States has at least one thing in common, and that is smoke. It is only of comparative recent date that smoke has been given serious consideration, outside of the office of smoke inspector and members of the anti-smoke league. The question of smoke is not a new one, for publications as to injury and legislation, date back to 1845. But since that time, we have had the great movement of people from the country to the city, in addition to the great immigration tide and the result is that large industrial centers have been built up. Smoke then has been considered as a ''necessary evil'' and has been looked upon as showing signs of prosperity to such centers.