Chapter IX · (continued 5)

It might be well to mention here the divers who work by means of apparatus. The ancients had knowledge of contrivances whereby they could stay under water some time. Aristotle speaks of an instrument by which divers could rest under water in communication with the air, and compares it with the trunk of an elephant wading a stream deeper than his height. In the presence of Charles V diving bells were used by the Greeks in 1540. In 1660 some of the cannon of the sunken ships of the Spanish Armada were raised by divers in diving bells. Since then various improvements in submarine armor have been made, gradually evolving into the present perfected diving apparatus of to-day, by which men work in the holds of vessels sunk in from 120 to 200 feet of water. The enormous pressure of the water at these great depths makes it necessary to have suits strong enough to resist it. Lambert, a celebrated English diver, recovered L90,000 in specie from the steamer Alphonso XII, a Spanish mail boat belonging to the Lopez line, which sank off Point Gando, Grand Canary, in 26 1/2 fathoms of water. For nearly six months the salvage party, despatched by the underwriters in May, 1885, persevered in the operations; two divers lost their lives, the golden bait being in the treasure-room beneath the three decks, but Lambert finished the task successfully.

Deep-sea divers only acquire proficiency after long training. It is said that as a rule divers are indisposed to taking apprentices, as they are afraid of their vocation being crowded and their present ample remuneration diminished. At present there are several schools. At Chatham, England, there is a school of submarine mining, in which men are trained to lay torpedoes and complete harbor defense. Most of these divers can work six hours at a time in from 35 to 50 feet of water. Divers for the Royal Navy are trained at Sheerness. When sufficiently trained to work at the depth of 150 feet seamen-divers are fully qualified, and are drafted to the various ships. They are connected with an air-pump in charge of trustworthy men; they signal for their tools and material, as well as air, by means of a special line for this purpose. At some distance below the water the extraordinary weight of the suits cannot be felt, and the divers work as well in armor as in ordinary laboring clothes. One famous diver says that the only unpleasant experience he ever had in his career as a diver, not excepting the occasion of his first dive, was a drumming in the ears, as a consequence of which, after remaining under water at a certain work for nine hours, he completely lost the use of one ear for three months, during which time he suffered agony with the earache. These men exhibit absolute indifference to the dangers attached to their calling, and some have been known to sleep many fathoms beneath the surface. Both by means of their signal lines and by writing on a slate they keep their associates informed of the progress of their work.

Suspension of the Pulse.—In some cases the pulse is not apparent for many days before actual death, and there have been instances in which, although the pulse ceased for an extended period, the patient made an ultimate recovery. In reviewing the older literature we find that Ballonius mentions an instance in which the pulse was not apparent for fourteen days before complete asphyxia. Ramazzini describes a case of cessation of the pulse four days before death. Schenck details the history of a case in which the pulse ceased for three days and asphyxia was almost total, but the patient eventually recovered. There is a noteworthy observation, in which there was cessation of the pulse for nine days without a fatal issue.

Some persons seem to have a preternatural control over their circulatory system, apparently enabling them to produce suspension of cardiac movement at will. Cheyne speaks of a Colonel Townshend who appeared to possess the power of dying, as it were, at will,—that is, so suspending the heart's action that no pulsation could be detected. After lying in this state of lifelessness for a short period, life would become slowly established without any consciousness or volition on the man's part. The longest period in which he remained in this death-like condition was about thirty minutes. A postmortem examination of this person was awaited with great interest; but after his death nothing was found to explain the power he possessed over his heart.

Saint Augustin knew of a priest named Rutilut who had the power of voluntarily simulating death. Both the pulsation and respiration was apparently abolished when he was in his lifeless condition. Burning and pricking left visible effects on the skin after his recovery, but had no apparent effect on his lethargy. Chaille reports an instance of voluntary suspension of the pulse.

Relative to hibernation, it is well-known that mice, snakes, and some reptiles, as well as bees, sometimes seem to entirely suspend animation for an extended period, and especially in the cold weather. In Russia fish are transported frozen stiff, but return to life after being plunged into cold water. A curious tale is told by Harley, from Sir John Lubbock, of a snail brought from Egypt and thought to be dead. It was placed on a card and put in position on a shelf in the British Museum in March, 1845. In March, 1850 after having been gummed to a label for five years, it was noticed to have an apparent growth on its mouth and was taken out and placed in water, when it soon showed signs of life and ate cabbage leaves offered to it. It has been said, we think with credible evidence, that cereal seeds found in the tombs with mummies have grown when planted, and Harley quotes an instance of a gentleman who took some berries, possibly the remnants of Pharaoh's daughter's last meal, coming as they did from her mummified stomach after lying dormant in an Egyptian tomb many centuries, and planted them in his garden, where they soon grew, and he shortly had a bush as flourishing as any of those emanating from fresh seeds.

Human hibernation is an extremely rare anomaly. Only the fakirs of India seem to have developed this power, and even the gifted ones there are seldom seen. Many theories have been advanced to explain this ability of the fakirs, and many persons have discredited all the stories relative to their powers; on the other hand, all who have witnessed their exhibitions are convinced of their genuineness. Furthermore, these persons are extremely scarce and are indifferent to money; none has been enticed out of his own country to give exhibitions. When one dies in a community, his place is never filled—proving that he had no accomplices who knew any fraudulent secret practices, otherwise the accomplice would soon step out to take his place. These men have undoubtedly some extraordinary mode of sending themselves into a long trance, during which the functions of life are almost entirely suspended. We can readily believe in their ability to fast during their periods of burial, as we have already related authentic instances of fasting for a great length of time, during which the individual exercised his normal functions.

To the fakir, who neither visibly breathes nor shows circulatory movements, and who never moves from his place of confinement, fasting should be comparatively easy, when we consider the number of men whose minds were actively at work during their fasts, and who also exercised much physical power.

Harley says that the fakirs begin their performances by taking a large dose of the powerfully stupefying "bang," thus becoming narcotized. In this state they are lowered into a cool, quiet tomb, which still further favors the prolongation of the artificially induced vital lethargy; in this condition they rest for from six to eight weeks. When resurrected they are only by degrees restored to life, and present a wan, haggard, debilitated, and wasted appearance. Braid is credited, on the authority of Sir Claude Wade, with stating that a fakir was buried in an unconscious state at Lahore in 1837, and when dug up, six weeks later, he presented all the appearances of a dead person. The legs and arms were shrunken and stiff, and the head reclined on the shoulder in a manner frequently seen in a corpse. There was no pulsation of the heart or arteries of the arm or temple—in fact, no really visible signs of life. By degrees this person was restored to life. Every precaution had been taken in this case to prevent the possibility of fraud, and during the period of interment the grave was guarded night and day by soldiers of the regiment stationed at Lahore.

Honigberger, a German physician in the employ of Runjeet Singh, has an account of a fakir of Punjaub who allowed himself to be buried in a well-secured vault for such a long time that grain sown in the soil above the vault sprouted into leaf before he was exhumed. Honigberger affirms that the time of burial was over 40 days, and that on being submitted to certain processes the man recovered and lived many years after. Sir Henry Lawrence verified the foregoing statements. The chest in which the fakir was buried was sealed with the Runjeet stamp on it, and when the man was brought up he was cold and apparently lifeless. Honigberger also states that this man, whose name was Haridas, was four months in a grave in the mountains; to prove the absolute suspension of animation, the chin was shaved before burial, and at exhumation this part was as smooth as on the day of interment. This latter statement naturally calls forth comment when we consider the instances that are on record of the growth of beard and hair after death.

There is another account of a person of the same class who had the power of suspending animation, and who would not allow his coffin to touch the earth for fear of worms and insects, from which he is said to have suffered at a previous burial.

It has been stated that the fakirs are either eunuchs or hermaphrodites, social outcasts, having nothing in common with the women or men of their neighborhood; but Honigberger mentions one who disproved this ridiculous theory by eloping to the mountains with his neighbor's wife.

Instances of recovery after asphyxia from hanging are to be found, particularly among the older references of a time when hanging was more common than it is to-day. Bartholinus, Blegny, Camerarius, Morgagni, Pechlin, Schenck, Stoll, and Wepfer all mention recovery after hanging. Forestus describes a case in which a man was rescued by provoking vomiting with vinegar, pepper, and mustard seed. There is a case on record in which a person was saved after hanging nineteen minutes. There was a case of a man brought into the Hopital Saint-Louis asphyxiated by strangulation, having been hung for some time. His rectal temperature was only 93.3 degrees F., but six hours after it rose to 101.6 degrees F., and he subsequently recovered. Taylor cites the instance of a stout woman of forty-four who recovered from hanging. When the woman was found by her husband she was hanging from the top of a door, having been driven to suicide on account of his abuse and intemperance. When first seen by Taylor she was comatose, her mouth was surrounded by white froth, and the swollen tongue protruded from it. Her face was bloated, her lips of a darkened hue, and her neck of a brown parchment-color. About the level of the larynx, the epidermis was distinctly abraded, indicating where the rope had been. The conjunctiva was insensible and there was no contractile response of the pupil to the light of a candle. The reflexes of the soles of the feet were tested, but were quite in abeyance. There was no respiratory movement and only slight cardiac pulsation. After vigorous measures the woman ultimately recovered. Recovery is quite rare when the asphyxiation has gone so far, the patients generally succumbing shortly after being cut down or on the following day. Chevers mentions a most curious case, in which cerebral congestion from the asphyxiation of strangling was accidentally relieved by an additional cut across the throat. The patient was a man who was set upon by a band of Thugs in India, who, pursuant to their usual custom, strangled him and his fellow-traveler. Not being satisfied that he was quite dead, one of the band returned and made several gashes across his throat. This latter action effectually relieved the congestion caused by the strangulation and undoubtedly saved his life, while his unmutilated companion was found dead. After the wounds in his throat had healed this victim of the Thugs gave such a good description of the murderous band that their apprehension and execution soon followed.

Premature Burial.—In some instances simulation of death has been so exact that it has led to premature interment. There are many such cases on record, and it is a popular superstition of the laity that all the gruesome tales are true of persons buried alive and returning to life, only to find themselves hopelessly lost in a narrow coffin many feet below the surface of the earth. Among the lower classes the dread of being buried before life is extinct is quite generally felt, and for generations the medical profession have been denounced for their inability to discover an infallible sign of death. Most of the instances on record, and particularly those from lay journals, are vivid exaggerations, drawn from possibly such a trivial sign as a corpse found with the fist tightly clenched or the face distorted, which are the inspiration of the horrible details of the dying struggles of the person in the coffin. In the works of Fontenelle there are 46 cases recorded of the premature interment of the living, in which apparent has been mistaken for real death. None of these cases, however, are sufficiently authentic to be reliable. Moreover, in all modern methods of burial, even if life were not extinct, there could be no possibility of consciousness or of struggling. Absolute asphyxiation would soon follow the closing of the coffin lid.

We must admit, however, that the mistake has been made, particularly in instances of catalepsy or trance, and during epidemics of malignant fevers or plagues, in which there is an absolute necessity of hasty burial for the prevention of contagion. In a few instances on the battle-field sudden syncope, or apparent death, has possibly led to premature interment; but in the present day this is surely a very rare occurrence. There is also a danger of mistake from cases of asphyxiation, drowning, and similar sudden suspensions of the vital functions.

It is said that in the eighty-fourth Olympiad, Empedocles restored to life a woman who was about to be buried, and that this circumstance induced the Greeks, for the future protection of the supposed dead, to establish laws which enacted that no person should be interred until the sixth or seventh day. But even this extension of time did not give satisfaction, and we read that when Hephestion, at whose funeral obsequies Alexander the Great was present, was to be buried his funeral was delayed until the tenth day. There is also a legend that when Acilius Aviola fell a victim to disease he was burned alive, and although he cried out, it was too late to save him, as the fire had become so widespread before life returned.

While returning to his country house Asclepiades, a physician denominated the "God of Physic," and said to have been a descendant of aesculapius, saw during the time of Pompey the Great a crowd of mourners about to start a fire on a funeral pile. It is said that by his superior knowledge he perceived indications of life in the corpse and ordered the pile destroyed, subsequently restoring the supposed deceased to life. These examples and several others of a similar nature induced the Romans to delay their funeral rites, and laws were enacted to prevent haste in burning, as well as in interment. It was not until the eighth day that the final rites were performed, the days immediately subsequent to death having their own special ceremonies. The Turks were also fearful of premature interment and subjected the defunct to every test; among others, one was to examine the contractility of the sphincter and, which shows their keen observation of a well-known modern medical fact.

According to the Memoirs of Amelot de la Houssaye, Cardinal Espinola, Prime Minister to Philip II, put his hand to the embalmer's knife with which he was about to be opened; It is said that Vesalius, sometimes called the "Father of Anatomy," having been sent for to perform an autopsy on a woman subject to hysteric convulsions, and who was supposed to be dead, on making the first incision perceived by her motion and cries that she was still alive. This circumstance, becoming known, rendered him so odious that he had to leave the community in which he practiced, and it is believed that he never entirely recovered from the shock it gave him. The Abbe Prevost, so well known by his works and the singularities of his life, was seized by apoplexy in the Forest of Chantilly on October 23, 1763. His body was carried to the nearest village, and the officers of justice proceeded to open it, when a cry he sent forth frightened all the assistants and convinced the surgeon in charge that the Abbe was not dead; but it was too late to save him, as he had already received a mortal wound.

Massien speaks of a woman living in Cologne in 1571 who was interred living, but was not awakened from her lethargy until a grave-digger opened her grave to steal a valuable ring which she wore. This instance has been cited in nearly every language. There is another more recent instance, coming from Poitiers, of the wife of a goldsmith named Mernache who was buried with all her jewels. During the night a beggar attempted to steal her jewelry, and made such exertion in extracting one ring that the woman recovered and was saved. After this resurrection she is said to have had several children. This case is also often quoted. Zacchias mentions an instance which, from all appearances, is authentic. It was that of a young man, pest-stricken and thought to be dead, who was placed with the other dead for burial. He exhibited signs of life, and was taken back to the pest-hospital. Two days later he entered a lethargic condition simulating death, and was again on his way to the sepulcher, when he once more recovered.

It is said that when the body of William, Earl of Pembroke, who died April 10, 1630, was opened to be embalmed, the hand raised when the first incision was made. There is a story of an occurrence which happened on a return voyage from India. The wife of one of the passengers, an officer in the army, to all appearances died. They were about to resort to sea-burial, when, through the interposition of the husband, who was anxious to take her home, the ship-carpenters started to construct a coffin suitable for a long voyage, a process which took several days, during which time she lay in her berth, swathed in robes and ready for interment. When the coffin was at last ready the husband went to take his last farewell, and removed the wedding-ring, which was quite tightly on her finger. In the effort to do this she was aroused, recovered, and arrived in England perfectly well.

It is said that when a daughter of Henry Laurens, the first President of the American Congress, died of small-pox, she was laid out as dead, and the windows of the room were opened for ventilation. While left alone in this manner she recovered. This circumstance so impressed her illustrious father that he left explicit directions that in case of his death he should be burned. The same journal also contains the case of a maid-servant who recovered thrice on her way to the grave, and who, when really dead, was kept a preposterous length of time before burial.

The literature on this subject is very exhaustive, volumes having been written on the uncertainty of the signs of death, with hundreds of examples cited illustrative of the danger of premature interment. The foregoing instances have been given as indicative of the general style of narration; for further information the reader is referred to the plethora of material on this subject.

Postmortem Anomalies.—Among the older writers startling movements of a corpse have given rise to much discussion, and possibly often led to suspicion of premature burial. Bartholinus describes motion in a cadaver. Barlow says that movements were noticed after death in the victims of Asiatic cholera. The bodies were cold and expressions were death-like, but there were movements simulating natural life. The most common was flexion of the right leg, which would also be drawn up toward the body and resting on the left leg. In some cases the hand was moved, and in one or two instances a substance was grasped as if by reflex action. Some observers have stated that reflex movements of the face were quite noticeable. These movements continued sometimes for upward of an hour, occurring mostly in muscular subjects who died very suddenly, and in whom the muscular irritability or nervous stimulus or both had not become exhausted at the moment of dissolution. Richardson doubts the existence of postmortem movements of respiration.

Snow is accredited with having seen a girl in Soho who, dying of scarlet fever, turned dark at the moment of death, but in a few hours presented such a life-line appearance and color as to almost denote the return of life. The center of the cheeks became colored in a natural fashion, and the rest of the body resumed the natural flesh color. The parents refused to believe that death had ensued. Richardson remarks that he had seen two similar cases, and states that he believes the change is due to oxidation of the blood surcharged with carbon dioxid. The moist tissues suffuse carbonized blood, and there occurs an osmotic interchange between the carbon dioxid and the oxygen of the air resulting in an oxygenation of the blood, and modification of the color from dark venous to arterial red.

A peculiar postmortem anomaly is erection of the penis. The Ephemerides and Morgagni discuss postmortem erection, and Guyon mentions that on one occasion he saw 14 negroes hanged, and states that at the moment of suspension erection of the penis occurred in each; in nine of these blacks traces of this erectile state were perceived an hour after death.

Cadaveric perspiration has been observed and described by several authors, and Paullini has stated that he has seen tears flow from the eyes of a corpse.

The retardation of putrefaction of the body after death sometimes presents interesting changes. Petrifaction or mummification of the body are quite well known, and not being in the province of this work, will be referred to collateral books on this subject; but sometimes an unaccountable preservation takes place. In a tomb recently opened at Canterbury Cathedral, a for the purpose of discovering what Archbishop's body it contained, the corpse was of an extremely offensive and sickening odor, unmistakably that of putrefaction. The body was that of Hubert Walter, who died in 1204 A.D., and the decomposition had been retarded, and was actually still in progress, several hundred years after burial.

Retardation of the putrefactive process has been noticed in bodies some years under water. Konig of Hermannstadt mentions a man who, forty years previous to the time of report, had fallen under the waters of Echoschacht, and who was found in a complete state of preservation.

Postmortem Growth of Hair and Nails.—The hair and beard may grow after death, and even change color. Bartholinus recalls a case of a man who had short, black hair and beard at the time of interment, but who, some time after death, was found to possess long and yellowish hair. Aristotle discusses postmortem growth of the hair, and Garmanus cites an instance in which the beard and hair were cut several times from the cadaver. We occasionally see evidences of this in the dissecting-rooms. Caldwell mentions a body buried four years, the hair from which protruded at the points where the joints of the coffin had given away. The hair of the head measured 18 inches, that of the beard eight inches, and that on the breast from four to six inches. Rosse of Washington mentions an instance in which after burial the hair turned from dark brown to red, and also cites a case in a Washington cemetery of a girl, twelve or thirteen years old, who when exhumed was found to have a new growth of hair all over her body. The Ephemerides contains an account of hair suddenly turning gray after death.

Nails sometimes grow several inches after death, and there is on record the account of an idiot who had an idiosyncrasy for long nails, and after death the nails were found to have grown to such an extent that they curled up under the palms and soles.

The untoward effects of the emotions on the vital functions are quite well exemplified in medical literature. There is an abundance of cases reported in which joy, fear, pride, and grief have produced a fatal issue. In history we have the old story of the Lacedemonian woman who for some time had believed her son was dead, and who from the sudden joy occasioned by seeing him alive, herself fell lifeless. There is a similar instance in Roman history. Aristotle, Pliny, Livy, Cicero, and others cite instances of death from sudden or excessive joy. Fouquet died of excessive joy on being released from prison. A niece of the celebrated Leibnitz immediately fell dead on seeing a casket of gold left to her by her deceased uncle.

Galen mentions death from joy, and in comment upon it he says that the emotion of joy is much more dangerous than that of anger. In discussing this subject, Haller says that the blood is probably sent with such violence to the brain as to cause apoplexy. There is one case on record in which after a death from sudden joy the pericardium was found full of blood. The Ephemerides, Marcellus Donatus, Martini, and Struthius all mention death from joy.

Death from violent laughter has been recorded, but in this instance it is very probable that death was not due to the emotion itself, but to the extreme convulsion and exertion used in the laughter. The Ephemerides mentions a death from laughter, and also describes the death of a pregnant woman from violent mirth. Roy, Swinger, and Camerarius have recorded instances of death from laughter. Strange as it may seem, Saint-Foix says that the Moravian brothers, a sect of Anabaptists having great horror of bloodshed, executed their condemned brethren by tickling them to death.

Powerfully depressing emotions, which are called by Kant "asthenic," such as great and sudden sorrow, grief, or fright, have a pronounced effect on the vital functions, at times even causing death. Throughout literature and history we have examples of this anomaly. In Shakespeare's "Pericles," Thaisa, the daughter to Simonides and wife of Pericles, frightened when pregnant by a threatened shipwreck, dies in premature childbirth.

In Scott's "Guy Mannering," Mrs. Bertram, on suddenly learning of the death of her little boy, is thrown into premature labor, followed by death. Various theories are advanced in explanation of this anomaly. A very plausible one is, that the cardiac palsy is caused by energetic and persistent excitement of the inhibitory cardiac nerves. Strand is accredited with saying that agony of the mind produces rupture of the heart. It is quite common to hear the expression, "Died of a broken heart;" and, strange to say, in some cases postmortem examination has proved the actual truth of the saying. Bartholinus, Fabricius Hildanus, Pliny, Rhodius, Schenck, Marcellus Donatus, Riedlin, and Garengeot speak of death from fright and fear, and the Ephemerides describes a death the direct cause of which was intense shame. Deleau, a celebrated doctor of Paris, while embracing his favorite daughter, who was in the last throes of consumption, was so overcome by intense grief that he fell over her corpse and died, and both were buried together.

The fear of child-birth has been frequently cited as a cause of death McClintock quotes a case from Travers of a young lady, happily married; who entertained a fear of death in child-birth; although she had been safely delivered, she suddenly and without apparent cause died in six hours. Every region of the body was examined with minutest care by an eminent physician, but no signs indicative of the cause of death were found. Mordret cites a similar instance of death from fear of labor. Morgagni mentions a woman who died from the disappointment of bearing a girl baby when she was extremely desirous of a boy.

The following case, quoted from Lauder Brunton, shows the extent of shock which may be produced by fear: Many years ago a janitor of a college had rendered himself obnoxious to the students, and they determined to punish him. Accordingly they prepared a block and an axe, which they conveyed to a lonely place, and having appropriately dressed themselves, some of them prepared to act as judges, and sent others of their company to bring him before them. He first affected to treat the whole affair as a joke, but was solemnly assured by the students that they meant it in real earnest. He was told to prepare for immediate death. The trembling janitor looked all around in the vain hope of seeing some indication that nothing was really meant, but stern looks met him everywhere. He was blindfolded, and made to kneel before the block. The executioner's axe was raised, but, instead of the sharp edge, a wet towel was brought sharply down on the back of the neck. The bandage was now removed from the culprit's eyes, but to the horror and astonishment of the students they found that he was dead. Such a case may be due to heart-failure from fear or excitement.

It is not uncommon that death ensues from the shock alone following blows that cause no visible injury, but administered to vital parts. This is particularly true of blows about the external genital region, or epigastrium, where the solar plexus is an active factor in inhibition. Ivanhoff of Bulgaria in 1886 speaks of a man of forty-five who was dealt a blow on the testicle in a violent street fight, and staggering, he fell insensible. Despite vigorous medical efforts he never regained consciousness and died in forty-five minutes. Postmortem examination revealed everything normal, and death must have been caused by syncope following violent pain. Watkins cites an instance occurring in South Africa. A native shearing sheep for a farmer provoked his master's ire by calling him by some nickname. While the man was in a squatting posture the farmer struck him in the epigastrium. He followed this up by a kick in the side and a blow on the head, neither of which, however, was as severe as the first blow. The man fell unconscious and died. At the autopsy there were no signs indicative of death, which must have been due to the shock following the blow on the epigastrium.

As illustrative of the sensitiveness of the epigastric region, Vincent relates the following case: "A man received a blow by a stick upon the epigastrium. He had an anxious expression and suffered from oppression. Irregular heart-action and shivering were symptoms that gradually disappeared during the day. In the evening his appetite returned and he felt well; during the night he died without a struggle, and at the autopsy there was absolutely nothing abnormal to be found." Blows upon the neck often produce sudden collapse. Prize-fighters are well aware of the effects of a blow on the jugular vein. Maschka, quoted by Warren, reports the case of a boy of twelve, who was struck on the anterior portion of the larynx by a stone. He fell lifeless to the ground, and at autopsy no local lesion was found nor any lesion elsewhere. The sudden death may be attributed in this case partly to shock and partly to cerebral anemia.

Soldiers have been seen to drop lifeless on the battle-field without apparent injury or organic derangement; in the olden times this death was attributed to fear and fright, and later was supposed to be caused by what is called "the wind of a cannon-ball." Tolifree has written an article on this cause of sudden death and others have discussed it. By some it is maintained that the momentum acquired by a cannon-ball generates enough force in the neighboring air to prostrate a person in the immediate vicinity of its path of flight.