Page:Popular Science Monthly Volume 68.djvu/371

Rh. There should, it seems to me, be maintained, in connection with all great cities, a series of broad avenues converging towards them from all the points of the compass, free from buildings, and covered with vegetation. The parks and open spaces in our cities are called their lungs, but the lungs are not of much use without the windpipe, and the green avenues I suggest would act in that capacity, and allow an inrush of fresh air and the escape of the vitiated air which is always accumulating in cities. These avenues, I have said, should be clothed in vegetation, and to my thinking the preservation of vegetation, not only around our great cities, but throughout the country generally, is becoming a matter of grave import. Sir James Dewar once calculated that a healthy man evolves on the average about 200 pounds of carbon in the form of carbonic acid annually, and as an acre of the best cultivated land fixes annually about 2,200 pounds of carbon, it follows that one acre of land can economize as much carbon as is supplied by eleven persons. The Crystal Palace covers an area of sixteen acres. If the atmosphere had to be kept pure by interior vegetation, without external ventilation, it could not permanently contain more than 365 persons without an increasing aerial contamination. But the vegetation in the large Crystal Palace, this island of ours, is being constantly reduced in amount. Enormous tracts of land once cultivated have been appropriated by highways and railways, and works and habitations, and at the same time there has been an enormous increase in the output of carbonic acid and the demand for oxygen by combustion in the consumption of fuel by manufactures of all kinds and for domestic purposes and by the respiration of animals and human beings. The revivification of the air by home industry is gradually decreasing, and the day may come when we shall be entirely dependent on imported oxygen as well as imported food, and will have to trust to the ocean to dispose of our surplus carbonic acid. At present the air of our large towns and especially those with narrow streets and towering buildings is often a very deleterious compound.

It is to the rise of the suburb—the island suburb—set in a sea of chlorophyll easily accessible, well planned, honestly built, that we must look in the first instance for the removal of some of the afflictions that overcrowding has brought upon us. But the suburbs, while it may do much, can not do everything, and there are other sources of relief, which it is our duty to turn to and to improve. We must take measures to reduce the influx of population into our already congested towns, and to keep on the land those who have been born and brought up on it and to bring back to the land those who have inconsiderately left it. Beyond the city and its satellites, we must afford to those who are weary of the dirt, confinement, dreariness and ugliness of over-crowded quarters, room and opportunity for healthy, moral and physical life. And there