How To Witness a Mirage

Urbana Courier-Herald August 1, 1906

Professor Dripp of the University Tells Courier-Herald Readers How.

DESERT OR PLAINS ARE FAR FROM NECESSARY

West Illinois Street is Recommended as a Suitable Location.

During the second semester of the University year just closed the members of a class in advanced Optics undertook, with a fair degree of success, to reproduce a mirage in the Physics laboratory. This phenomenon, as we are told In the physical geographies, is to be seen quite frequently in desert lands and on the plains when the sun is shining brightly. As we recall It gives the traveler the impression that a body of water lies ahead.

It is not necessary to go to the desert or even to the great plains of this country to witness a mirage, nor is it advised to reproduce it In the laboratory, for most every town the size of Urbana affords one or more places where it may be observed as real and true to life as that seen by any traveler, though possibly not on so large a scale. Any paved street that is perfectly level for four or five blocks will answer. But to view it with ease there should be a depression in the street of sufficient depth that the observer's eye is just in line with or sights the lever portion. In order that the mirage may be seen to the best advantage the sun must shine brigthly and there should be no wind. The phenomenon is not confined to midsummer, it may be seen quite as well in both the spring and fall, in fact it has been noticed a number of times during the freezing weather providing the weather conditions are right.

The street that probably is best adapted for viewing the mirage Is West Illinois street, says Charles T. Dripp, assistant professor of physics at the University of Illinois. If the observer will repair to the intersection of Busey avenue and Illinois street on any day between ten a.m. and three p.m. when the sun is shining brightly and there is not too much air stirring and look west toward the University he will observe apparently a small expanse of water stretching across the street about midway between his position and the campus. Pedestrians and vehicles passing on Mathews avenue will have inverted images clearly visible in this phantom lake.

The observation is easily made, either on foot, in a carriage or on a wheel. The exact position that the observer must take is readily found by trial; for instance, a person six feet tall will find his line of sight correct when he is standing at tht corner of the intersection of the two streets. To any one who has never seen a mirage, this one on Illinois street will prove interesting and novel.