The new air world

by Willis L. Moore

Artificial Rain Making. Many swindlers have preyed upon the credulity of the public by claiming to have a process for the making of rain, and in some cases large sums of money have been paid by commercial or other associations to these charlatans. In 1892 the United States Congress appropriated $20,000 for the testing of the theory that rain could be created by the setting off of large quantities of explosives. The experiment was unsuccessful, as the scientists of the Government insisted it would be. The Greeks had a popular belief that when a host of their soldiers went out to meet an army of Persians the vapor rising from the hot breath, blood, and sweat of the struggling mass was later condensed into rain by the concussion of the battle clubs and the hoarse cries of the victors, and many of the veterans of our Civil War were firm in the opinion that their great battles were followed by rains that were the result of the cannonading. Both the Greeks and our American soldiers were mistaken. Rain often has fallen at the close of great battles, not because of the concussion of the conflict, but because rain falls on an average of one day in three in the regions where most of the great battles have been fought, and the movement of armies began on the fair days when travel was good. If it were the custom to begin battles on rainy days we would have the contrary and equally erroneous theory that concussion clears the atmosphere.

Prevention of Hail by the Firing of Guns. Even a Papal decree was not entirely effective in preventing the people in southern Europe from ringing the church bells to prevent the formation of hail when a storm threatened, and within the past quarter-century large grants of public money were foolishly wasted in the firing by the vineyardists of France and other parts of Europe of a gun specially designed to destroy hail clouds. These guns sent harmless smoke rings a few feet aloft. The writer felt constrained to employ the extensive machinery of the Weather Bureau to counteract the effect of glowing accounts of the success of these guns that were sent to this country by some of the ignorant persons employed by this Government to represent us as consuls abroad. Even though the hail-destroying guns occasionally were choked with hail it was difficult for scientists to prevail upon the public to stop their foolish and wasteful practice.

CHAPTER XVI
DEVELOPMENT OF THE AMERICAN WEATHER SERVICE

THE LARGEST AND THE MOST EFFECTIVE METEOROLOGICAL BUREAU IN THE WORLD

Even to those who are familiar with the application of meteorological science to the making of weather forecasts, and with the material benefits accruing to the commerce and industry of the United States from timely warnings of marine storms, frosts, and cold waves, it will be interesting to note that at the time of the founding of the first of the thirteen original Colonies, at Jamestown, Virginia, in 1607, practically nothing was known of the properties of the air or of methods for measuring its forces. To-day electrically recording automatic meteorological instruments measure and transcribe for each moment of time at two hundred stations in the United States, the temperature, the air pressure, the velocity of the wind, the direction of the wind, the beginning and ending of rainfall, with the amount of precipitation; and the presence of sunshine or cloud; and three thousand voluntary observers each day record the temperature and the rainfall.

That we live in an age of great intellectual acumen, and that he is indeed a wise prophet who can even dimly outline the possibilities of the next century, is fitly shown by the development of meteorological science during the recollection of the present generation; although one must admit that in the making of weather forecasts, valuable as they are, we have not advanced beyond the partly empirical stage. It is, therefore, improbable that in the making of these forecasts we shall ever attain the accuracy acquired by theoretical astronomy in predicting the date of an eclipse or the culmination of any celestial event.

It was not until 1644, twenty-four years after the landing of the Pilgrims at Plymouth Rock, that Torricelli discovered the principle of the barometer and rendered it possible to measure the weight of the superincumbent air at any spot where the wonderful yet simple little instrument might be placed. Torricelli’s great teacher—Galileo—died without knowing why nature, under certain conditions, abhors a vacuum, but he had already discovered the principle of the thermometer. The data from the readings of these two instruments form the base of all meteorological science. Their inventors as little appreciated the value of their discoveries as they dreamed of the coming great western empire which should first use their instruments to measure the inception and development of storms, and later, with the aid of the electro-magnetic telegraph, to give warnings to threatened regions of the approach of hurricanes, cold waves, floods, and frosts that have been worth at least one hundred million dollars to this country during the past ten years without counting the many thousands of lives saved among mariners.

Doctor John Lining, of Charleston, South Carolina, kept a daily record of the temperature in this country as early as 1738, although the accurate thermometers of Fahrenheit had then been in use but a few years and the errors due to imperfect mechanical construction may have been considerable as compared with the refined instruments now used for measuring temperature. About one hundred years after the invention of the barometer, viz., in 1747, Benjamin Franklin, the patriot and statesman, the diplomat, the scientist, divined that certain storms may move in a direction opposite to the blowing of the wind and that they progress in an easterly direction. It was prophetic that this idea should come to him long before any one had ever seen charts showing observations simultaneously taken at many stations. But although his ideas in this respect were more momentous than his act of drawing the lightning from the clouds and identifying it with the electricity of the laboratory, yet his contemporaries thought little of his philosophy of storms, and it was soon forgotten. It will be interesting to learn how he reached his conclusion as to the cyclonic or eddy-like nature of storms. He had arranged with a co-worker at Boston to take observations of an eclipse at the same time that Franklin was taking readings at Philadelphia. Early on the evening of the eclipse an unusually severe northeast wind and rainstorm set in at Philadelphia and Franklin was unable to secure any observations. He reasoned that as the wind blew fiercely from the northeast the storm, of course, was coming from that direction, and Boston must have experienced its ravages before Philadelphia was reached. Reports indicated that the storm was widespread. What was the surprise of Franklin, when, after the slow passage of the mail by coach, he heard from his friend in Boston that the night of the eclipse had been clear and favorable for observations, but that a terrific northeast wind and rainstorm began early the following morning. Franklin then sent out inquiries to surrounding stage stations and found that at all places southwest of Philadelphia the storm began earlier and that the greater the distance the earlier the beginning as compared with its advent in Philadelphia; but northeast of Philadelphia the time of the beginning of the storm was later than at the latter city, the storm not reaching Boston until twelve hours after it began at Philadelphia. In considering these facts a line of inductive reasoning brought him to the conclusion that the wind always blows towards the center of the storm; that the northeast storm which Boston and Philadelphia had experienced was caused by the suction exercised by an advancing storm eddy from the west which drew the air rapidly from Boston toward Philadelphia, while the source of the attraction—the center of the storm eddy—was yet a thousand miles to the southwest of the latter place; that the velocity of the northeast wind increased as the center of the storm eddy advanced nearer and nearer from the southwest until the wind reached the conditions of a hurricane; that the wind between Boston and Philadelphia shifted its direction so as to come from the southwest after the center of the storm eddy had passed over this region; and that the force of the wind gradually decreased as the center of attraction—which always is the storm center—passed farther and farther away to the northeast.