No more double windows!” That was the title of an article I read in the Chicago Evening Post. The year was 1911 and the page was yellowed with age.

The unnamed author gushed: “The ancient double windows have almost disappeared from Chicago! Every city residence a quarter-century ago was built with a set of heavy outer windows. Their object was to protect the interior of the building from cold and drafts. It may be that they really were necessary before the city was closely built up or the modern systems of heating were invented. Anyhow, the double windows began to disappear as the new steam systems were put in.

It lingers still in the suburbs, but is practically unknown in the urban apartment houses, which, we should say, is a very good thing. With double windows, the only air that crept into the house came through those little mousetrap openings in the bottoms of the frames. No matter how fine the day, or how warm, there was no way from October to May in which the life-giving oxygen could be gotten from outdoors into the upstairs rooms.”