作者：Darlington, Richard
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A Full Description of the Great Tornado in Chester County, Pa.试读：
THE GREAT TORNADO.
The Summer of 1877 has been remarkable in some localities for the severity of its storms. These, in several instances, have partaken of the character of tornadoes. Mt. Carmel, in Illinois, was nearly destroyed about the 20th of June last; Pensaukee, in Wisconsin, was nearly ruined on the 8th of July, and Pittston, in Massachusetts, suffered terribly from a tornado on the same day. While these great moving storm-clouds occur occasionally in some of the Southern States, they generally move through sparsely settled districts, and the damage inflicted excites but little attention elsewhere. In the West Indies, and in other tropical regions, these tornadoes are of frequent occurrence, and the damage is often fearful, whole towns being completely swept away. In the East Indies, and on the coast of India, these storms are known as Cyclones, because of their rotary motion—the Greek word Ruklos, from which "Cyclone" is derived, meaning "a whirl". A cyclone frequently extends across a great belt, and is from fifty to five hundred miles in width. It may last for hours, and if it occurs on the ocean it destroys most of the vessels within its reach. In the dreadful hurricane that fell upon Coringa, in India, in 1839, the town was destroyed and twenty thousand people lost their lives.
Cyclones or hurricanes of this class, do not occur in our northern States; tornadoes, however, do in rare instances. These extend in width not more than a few hundred yards, or even feet, and come and go within the space of one or two minutes. In power and violence, however, they are as destructive as the cyclones. In tornadoes the storm-cloud, in nearly all instances, has a rotary motion; the wind also sweeping forward progressively at the rate of from five to twenty miles an hour. Science has shown that in the latitude where these rare visitors come, they nearly always proceed from south-west to north-east. In the great Illinois hurricane in May, 1855, that passed over Cook county, it is said that a family of nine persons was carried up in the air in a frame house, four of the nine being killed outright and the remainder severely injured. The house went to pieces amid the fury of the storm. Generally these great storms are accompanied by peculiar electrical phenomena, though not in all instances. Rain and hail often go with them. The storm-cloud of a tornado is nearly always funnel-shaped, the small end of the funnel extending downward. It looks like an immense balloon, and revolves on its axis with fearful rapidity. The air beyond the limits of this cloud is also in rapid motion, but merely partakes of the character of a very high wind and is not particularly destructive. The death-dealing and destructive power of the storm is confined to the limit of the conical cloud. All movements for personal safety must extend entirely beyond the circumference established by the rotary motion. The primary cause of these tornadoes is probably due to a low barometric condition of the atmosphere accompanied by a high temperature, and spreading over an area of very irregular shape. An area of high barometer, accompanied by a low temperature, encroaches upon the former, and then comes the mighty effort to equalize these two different conditions of the atmosphere and restore the equilibrium, which is the constant effort of nature. The more diverse these two conditions are, the greater will be the struggle of the giants in the contest. Of course the electrical condition of the atmosphere existing at the time may form a very important factor in the tornado which may follow. What was the character and condition of the atmosphere on the memorable first of July last, when the storm-cloud which spread desolation over a narrow belt of not more than two hundred yards at most, swept across the western half of Chester county, Penn'a? The middle part of the day was hot and oppressive; the thermometer stood at about 92 and the barometer about 29.6. The atmosphere seemed very close, and the inhaling of air in the lungs was attended with rather more difficulty than usual. I remarked to a friend that there was a peculiar condition of the atmosphere, and yet who could have foretold the terrible results of that afternoon? The oldest inhabitant had never heard of a tornado in this section of country, and yet one was at hand. To give a faithful and accurate description of the movements and conduct of this storm-cloud, made it necessary for me to pass over the route of the moving mass and observe critically its results, and also to inquire of those living along and near its track what was its appearance, what was the direction of its sweep through the forest trees, how far the debris were carried, what amount of life was destroyed, what was the width of its track, and how the rotary motion of the cloud seemed to affect the buildings and obstacles that vainly attempted to resist its march in a direction a little south of east.
The first point of interest in connection with the tornado was about one mile south-east of the Gap station, on the Penn'a Rail Road, and about two miles west of the boundary line between Chester and Lancaster counties. From this point the storm-cloud proceeded for about two miles in a direction south 70 degrees east, or about 20 degrees south of a line running due east. About three-fourths of a mile east of Sadsbury Meeting House a slight change of direction occurred in the movement of the cloud, and it took a direction a little to the north, running south 75 degrees east. It proceeded, with slight local variations, for about eight miles in a direct line, and cutting a track about 200 yards wide, until it reached the property of William Hamill, in East Fallowfield township, near Newlin's Mill, and here it widened to about 300 yards, destroying the fences, crops, etc., on his property. At this point a slight change of direction occurred towards the south, bringing it into contact with the timber tracts of E. Phipps and Thos. Shields, in which a terrible destruction of forest trees occurred. It now veered to the north about ten degrees, and passed through the southern half of the village of Ercildoun in a line south 83 degrees east, or in a direction nearly due east, and continued thence until it arose in the air about half-a-mile east of Ercildoun, and proceeded, at a higher elevation, for about seven miles, relieving the farms and property of the intervening country from destruction. As it approached Broad Run, about a mile west of Marshallton, it descended sufficiently long to unroof and almost destroy the barns and out-buildings of two properties, owned respectively by Richard Baily and Joseph Marshall, of West Bradford township. Here it came to an end in its mad and reckless career. The two opposing currents of air had no doubt now become thoroughly blended and partook of the character of a high wind, fully relieved of its devastating properties. The storm-cloud was dissolved, or had permanently taken a higher elevation over a still greater amount of territory. The whole route of the tornado, as measured by its effects, was about 22 miles. The width of its track was from 100 to 300 yards, averaging generally about 200 yards. The following points also have been pretty clearly established by the use of the compass, and also by careful observation along the route of the storm:
First. That the general direction of the storm-cloud during the first half of its journey, to a point near Newlin's Mill, one mile west of Ercildoun, was south 75 deg. east, but at that point it changed and its course afterwards was south 83 deg. east, or nearly due east. Second. That the destruction of property was generally greater as the cloud moved across a valley. Third. That the velocity of the moving mass varied at different periods from 5 to 15 miles an hour, but twelve miles an hour would be considered a fair average. Fourth. That the trees along the southern side of the track of desolation were generally thrown with their tops towards the north, or at right angles to the direction of the progressive motion of the cloud, while those on the northern side were thrown in the opposite direction. Fifth. That in some instances houses and buildings near the centre of the track were but slightly injured. These cases, however, were rare. Sixth. That from local and other causes, the lower part of the conical cloud frequently moved out of a straight course, while the upper or larger part of the cone kept in a line very nearly direct. Seventh. That as soon as the cloud was formed, a roaring sound commenced, which continued without interruption during its entire course. This sound was not unlike continuous thunder. Eighth. That the movement of the storm-cloud was unaccompanied with much rain or hail, though one or the other fell at some distance north or south of the track, the sun frequently shining at the time. To explain some of these phenomena, even with the aid of science, is difficult. The storm-cloud itself was an entirely exceptional phenomenon in this latitude. Such an event had never occurred before in eastern Pennsylvania, and we are without the benefit of previous observation and experience. The great destruction of property in crossing valleys has excited marked attention. The cloud undoubtedly required an immense amount of air to feed it as it went along. Persons near its track say that they breathed with the greatest difficulty. The surrounding air must have been very rare; in fact, a partial exhaustion must have resulted from the absorption of air by the moving mass. In crossing a valley at right angles, or nearly so, the dense air up and down on either side, would be at hand to furnish it with the necessary material, thus increasing its power and devastation; this is one explanation. Another theory, which is probably the correct one, could safely be advanced upon plausible grounds. Supposing electricity to be the primal cause of the cloud itself, in passing across deep and irregular valleys with rugged surface, more electricity would be developed, and greater power would be infused into the revolving cone as it moved forward. When passing over a smooth, level plateau, it would excite less of the electrical fluid, and would hence be disarmed of a portion of its ability to destroy buildings and fences.
The second important point that we must consider is the increased destruction of property and great violence exhibited on the right side of the centre of the revolving axis of the storm-cloud, and a corresponding diminution of destructive power on the left side. The movement of the whirl was undoubtedly from right to left; the fallen trees indicate it. The forward motion of the hurricane would create a great inrushing of wind on the right side, and greater damage would result than upon the other side where the wind was returning to complete the rotary movement. While it is true the trees were overthrown to some extent in all directions, yet they mostly fell in the direction in which the wind struck them as it moved around in its whirling motion. The southern side of the track of desolation, however, presents evidence of the greatest power. The maple and other forest trees were frequently twisted entirely off, showing conclusively, that while they were first struck by the progressive motion, the rotary motion was sufficiently quick to locate the falling trunk. The great power of the storm-cloud was due to its revolution. In fact, this marks the difference between the high wind and the hurricane or tornado. The phenomena observed in connection with the storm of July first, are almost identical with those of similar character in the Southern States and West Indies.
The third subject presented for our consideration is the upward and downward currents which seemed to exist within the cloud. Objects were thrown upward to an immense distance, and the distance to which some objects were driven into the earth must convince us that there was a force downward of great power. It is true that a falling body, when influenced by gravity alone, will descend with great force, especially if started from a high point, but the deep excavations found in the track of the storm can only be accounted for by a downward current. The funnel-shaped cloud enlarging its circumference towards the top, would, with its centrifugal force resulting from its revolution, hurl bodies to a great distance, and we find the debris of this tornado hundreds of yards outside of its track, proving that when an object was carried up in the whirl, it was often thrown off, laterally for a great distance. A remarkable feature in connection with the tornado is the preservation of buildings in the track of the storm. Property on both sides of a house was sometimes destroyed, and yet the building itself was scarcely injured. This gap in the storm must have occurred from local causes, and from the gradual elevation and descent of the progressive movement of the cloud, thus carrying it over and beyond some of the objects in its track. Some cases of this character will be mentioned in the subsequent pages of this book.
The color and appearance of the storm cloud is worthy of consideration. By some who viewed it as it passed along, it is represented as being an immense balloon, extending to the height of several hundred feet, spreading out at the top, forming a funnel. It moved along at times with great rapidity, and at other times it seemed to halt, as if gathering strength for another effort. The color was variegated, the whole presenting rather a luminous appearance. Missiles of every kind could be distinctly seen in and through the body of the cloud. At first sight it seemed to be a barn on fire—the burning embers flying in every direction; but a closer inspection proved it not to be fire, but dirt and hay and timbers, intermingled with leaves and other light substances, giving it the appearance of an immense wind storm, which was the correct conclusion. Those who had a side view of the cloud state that it was quite light in appearance as it passed over grass fields and timber tracts, but when it reached a plowed field or a potato patch, it gathered up the dirt and loose material and became a very dark mass of matter, and presented a frightful appearance as it traveled forward with a velocity of a mile in four or five minutes. Such was its character as it approached the village of Ercildoun.
Jos. Brinton, who resides at Newlin's station, on the Penn'a and Delaware Rail Road, states that he observed the storm carefully as it came from the west. He was standing on his barn bridge at the time, and on looking over the high hill at the west of his residence his eyes were directed to a point just above the funnel of the cloud. He saw the clouds rise up at the circumference to a great height, and then pour over into the central cavity from all sides; this continued for some time. The funnel next appeared in full view, after the space of ten minutes. Then the body of a tree appeared above; it appeared motionless, and grew larger and larger as the cloud approached—the tree being carried with the storm; finally it disappeared. The body of the storm-cloud was now full of missiles, having the appearance of millions of birds sailing through the air, the whole moving mass being of a very dark color. As it moved forward these missiles were discharged in every direction. The conical column now became very tall, and was of a white color, in appearance not unlike the under cloud of a great rain storm. As clouds of smoke and dirt rolled up through the mass and were carried around by the rotary motion, the appearance was that of an immense building on fire. He pronounces the sight to have been awfully grand, and terrible beyond description. APPEARANCE OF THE STORM-CLOUD WHILE MOVING THROUGH JOSEPH BRINTON'S FIELD.
With a view of having correct data of the tornado, and placing the same upon record, in company with my friend and schoolmate Edwin Walton, of Highland township, I passed along the route of the storm-cloud. The first point of observation was near the residence of Jos. D. Pownell, Lancaster Co., Pa. He gave us a short account of the cloud, and of the movement of the currents of air which formed it. As he sat upon the front porch of his residence, he saw a strong current of air blowing from the south-west. To the north a storm had just passed, and a powerful current set in from that direction and blew directly across, coming in conflict with the current from the south-west. The whirl commenced on their coming together, and was set in motion about half-a-mile from his house and one mile south-east of the Gap station. This rotary motion or "whirl" probably resulted from the resistance encountered by these opposing currents of air, in their attempt to ascend vertically, there being less resistance in a lateral than in a vertical direction. The first movements of the cloud thus formed were of a decided character. Some children that were playing in a field near by, saw the danger ahead and fled to a lime-kiln, thus saving their lives. The cloud now reached a stream of water, and Mr. Pownell says the water was taken up and carried into the funnel of the cloud, leaving the bed of the stream dry.
It now approached his house with a continuous roaring sound, and he fled within. It passed along the north side of his house, overthrew his orchard, destroyed part of his corn crop, carried an apple tree fifty yards, and cut a track 150 yards wide and proceeded in the direction of Sadsbury Meeting House. His loss was about $300. The first building struck was a tenement house on the property of Elwood Pownell. It was located on the top of a hill that overlooked the surrounding country; an old colored man named Robert Johnston occupied it. The building was leveled to the ground. He stated that he was coming up the hill as the cloud approached, and sought safety by leaning against the bank and holding firmly to the fence; he was not injured. He is now living in the cellar of the house and crawls out into daylight when it is necessary; no movement is being made towards rebuilding his dwelling. Loss, $200. The storm-cloud next passed over Elwood Pownell's property. His wagon shed and carriage house are gone, and a large number of his apple trees was overthrown. His farming utensils were swept away, and the barn itself was moved fourteen inches from its foundation. The fences on the property were more or less demolished, but his whole loss was not very great. He states that his father-in-law was paying him a visit on that afternoon, but was unable to get home in the evening as his carriage was seized by the storm and carried away. Mr. Pownell further states that he saw the wind coming, and with the greatest difficulty reached the house, being unable to find the door-latch after he got there. He also experienced great difficulty in breathing. His loss was estimated at about $200. The storm now passed in the direction of a property on which Thomas Bonsall, Jr., resides, distant about one mile from Christiana. Two-thirds of the roof of his barn was carried off, and the eastern gable end fell with a crash, as the wind struck it. His orchard was destroyed, and also many of the fences on his property. The loss sustained on this property was about $300.
About a mile distant from Mr. Bonsall's buildings was a barn, said to be owned by a Building Association of West Chester. The roof of
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