It was at the end of the 19th century, when the tower had just finished, that Dr. Hénocque was studying the effects of the ascent to the summit on the human body, at a time when it was still possible to climb to feet to the top. The report which follows, which was written by this doctor, evokes a lot of physiological effects and details by type of efforts to be made. It mentions a unit of human effort, Kg.m, (weight x distance to be covered). The rest of this document contains the text he has written and provides Gustave Eiffel for the writing of his book "The 300m tower".
Introduction
When ascending the elevators to the terrace of the 3rd Tower Platform (278 m), the body is influenced by differences in altitude, temperature, ventilation; but, whatever may be the variation of these conditions, the engineers, the employees, the visitors, all those who are transported by elevator above the said platform, where the laboratories are situated, have found that they felt an impression in general analogous. Breathing becomes wider and easier; the pulse beats faster, then becomes more regular and more resistant. At the same time, they feel a sense of well-being, of general activity, of excitement. The satisfaction of an isolation on a plateau where such a vast horizon is developing, and where an air of great purity and particularly invigorating reign, determines, mainly in women, a psychic excitement resulting in cheerfulness, lively conversations joyful, laughter, the irresistible attraction to climb even higher, up to the flag, in short, a general excitement which reminds travelers of the fact that they caused climbs in the high mountain resorts. If the stay at the summit continues, this impression is accentuated. There is a sensation of remarkable appetite; at the same time, the mind being occupied by this splendid spectacle, the notion of the duration of the stay weakens singularly, then increases the desire to prolong the rest and this contemplation.
Note: This text from the nineteenth century, do not be surprised at the distinction that can be read between men and women about the natural euphoria that everyone feels to be at the top ...
These effects, due to rapid and fatigue-free transport in an atmospheric layer 300 m above the ground from which it is completely isolated, deserved to be studied with care. To this end, I made many observations which gave me interesting results that could not be suspected a priori. I will present here the most important part of this research by studying successively the principal phenomena of modification in circulation and respiration. I will examine especially the modifications produced in one of the physiological phenomena which summarize them all, the activity of reduction of the oxyhemoglobin, that is to say the activity of the respiratory exchanges between the blood and the elements of the tissues. The results obtained by this special examination are much more concordant and more demonstrative than the findings of pulse rate and respiration.
Mechanical work due to walking uphill
By studying the phenomena related to the activity of the reduction after a climb on foot by the stairs, I had the opportunity to make observations, which are not without interest, on the conditions in which this climb takes place and on the mechanical work that is developed there. I will point out that the Tower, by the exceptional development of an almost continuous staircase, lends itself particularly well to researches of this kind. It is the result of these which is indicated below.
Mechanical work due to climb
The walk up to the 3rd Tower platform includes a vertical climb of 277 m, and a horizontal course on the stairs and platforms of 438 m, following the table below.
These figures will allow us to calculate, for a man with an average weight of 70 kg, the mechanical work he must develop to climb the various floors taking into account its horizontal movement; we will deduce his work in kilograms very per second, involving the time of the ascent. These calculations will lead us to an estimate of the number of labor due to walking on a horizontal ground, the value of which, in spite of all the work done on this subject, remains rather uncertain. Let us first speak of the facts established by an already long series of observations. The normal time of the climb taken by the workers of the Tower, either during construction or during operation, is:
- At the 1st platform: 6 minutes
- At the 2nd platform: 21 minutes
- At the 3rd platform: 30 minutes
This speed of ascent was surpassed by Dr. Francis, who climbed in 21 minutes on the third floor, and by two students, MM. Duhamel and Murer, who climbed in 25 minutes. These are, to my knowledge, the shortest times that have been achieved to date (These figures are from the late nineteenth century) The famous traveler Mr. d'Abadie, aged 70, has made himself a Ascent ascension as fast as it could perform, It was 35 minutes. On the other hand, the duration of 60 minutes was carried out by two medical students who proposed to avoid fatigue (observations N ° 43 and 44).
These various times correspond to each other at a vertical average speed of 0.154 m. But they bring, especially for the third platform, shortness of breath and fatigue; such work could not be prolonged. We find, therefore, quite exaggerated the figure of 0.15 m found in most works dealing with the mechanical work which man can produce, such as the average of a speed which can be maintained for eight hours ( Courtesy, Animated Engines, and others). The fatigue is already much less with the usual duration of 45 minutes taken by men less exercised. Nevertheless, the staff of the Tower considers that it would be impossible, even normally, to maintain this duration during a daily work of 8 hours, and it generally thinks that the man, not to feel at the end of the day an excess of fatigue, could not perform more than 8 climbs per day of 8 hours of work, only one climb per hour. It is on these data of a prolonged experience that we will operate.
For a man whose average weight is 70 kg including clothing, the total mechanical work includes that due to the vertical rise of 277 m, that is, without any dispute, 70 x 277 = 19 390 Kgm, and more work due to its horizontal displacement on a flat ground of 438 m. This work is much more difficult to assess than the first, and needs to be studied with some developments.
This horizontal movement can occur only under the influence of a horizontal force whose point of application moves at a certain speed and which produces a certain mechanical work in kgm, adding to the first.
By calling this horizontal component of the step, ie the horizontal force that man must develop to maintain it on a flat ground, the total work done, expressed in kilogrammetres, is:
19 390 + F x 438
To realize the value of the horizontal component of the walk which we have called F, we can look for an equivalence between the total work above and that resulting from the displacement of a walker on a level ground during the same time. Mr. Courtois, a highway engineer, gives animated engines in his treatise, the speed of 1,00 m as the average normal for a traveler without burden on a good flat road. This speed corresponds to the normal rhythm at 70 double steps of 1.37 m length and has a course of 3700 m per hour. It can last for eight hours, or 40 km in a day. We consider that from the point of view of the muscular energy expenditure, we can assimilate the daily work of the 8 ascents of which we spoke to this horizontal course of 40 km during the same time. But the work during the 3600 "of the horizontal step is F x 1.60 x 3600, or F X 3.700.
If we accept the equivalence that I just indicated in the average work of a climb and that of a horizontal course of 5 700 m, we will have the equality: 10 300 + F x 438 = F x 5,700, hence: F = 19,390 / 5,322 = 3.80 Kg.
With this value of F, the work of ascension due to the horizontal displacement will be 3.80 x 438 = 1 664 kgm. Adding the work following the vertical, ie 19,390, the total work of the climb will be 19,390 + 1,991 = 21,054 Kgm for 3,600 ", or per second: 31,051 / 3,600 = 5.84 Kgm This figure is very close to that of 6 kgm per second generally accepted for the human force represented by the action of the man on a crank, and a little above that of 7 kgm, that is to say horse, which figure in most books.
It can be seen that the preceding figures correspond per hour to a vertical rise of 277 m, ie at a speed of 0.77 m per second. This figure is about half that of the author already quoted, M. Courtois, who wears it at 0.15 m for a prolonged average work. This last figure leads to quite erroneous consequences on the work of the man climbing a staircase. This value of 0.15m obtained momentarily by the highly trained workers, who ascend in half an hour, is about a maximum, but by no means an average. With this speed, the work of the workers is double of the previous one, that is to say 11.68 Kgm per second, which is certainly an excessive work beyond the human forces. We can therefore say that the work of climbing stairs is 6 kgm per second for continuous work and can be increased to 12 kgm for a single ascent. In a general way, by designating the weight of the man by P, the height of ascension by H, the horizontal distance traversed by D, and the time in seconds of the ascent by t, one will have equality:
P.H + F.D = 1,60.F.t, ie : F = P.H / (1,60t - D)
And the work T per second will be:
T = (1 / t) x (P.H + D.F) = (P.H / t) x (1 + D / (1,60 t - D))
If P = 68,50 Kg, t = 1 800, H = 277 and D = 438 that's means F = 7,8 Kg and T = 12,5 Kgm
It is with this formula that the values entered in the last column of Table No. 2 are calculated. The work following the vertical is indicated, in the example which we have just taken, by the figure of 18,073 kg. work following the horizontal by 3 410 which are in the ratio of 5.50 to 1.
Work in the descent
For the descent on foot, we have, as for the climb, consulted the staff of the Tower for which a prolonged experience gave the results that we will relate. The descent by the stairs of the 3rd platform on the ground requires a normal duration of 14 to 15 minutes, not to bring special fatigue. The pace of this descent is, from the point of view of the efforts developed, quite comparable to that of the climb in 45 minutes. The ratio of the speed of the climb to that of the descent would thus be from 1 to 3.
This ratio of 1 to 3 is maintained for the lively paces a little exceptional; the descent can be done in just 8 minutes, and comparable to the 25 minutes of the rapid rise. In the descent, the mechanical work is weak and the work is almost entirely a physiological work; however, it must be quite high because of the ratio of the speed of the climb to that of the descent. In a next chapter, we will see examples of the results produced by the descent on the activity of the reduction.
More research on this point would be very interesting and we propose to realize them soon, by making climbs in a continuous way during a whole day, the descents being done by the elevators, and by doing during a other day only descents, elevators used for climbs and for rest.
Oxyhemoglobin Reduction Activity
To understand the importance of this study, it is essential to recall in a few words the data on the role of oxyhemoglobin, and the changes it undergoes in the body.
Hemoglobin is the coloring material of blood. This substance contained in the globules of the blood, to which it gives a red color, contains all the iron of the blood; it owes its unstable combination with oxygen its role of agent vector of oxygen in the tissues. It is this which, charging itself in the lungs with the oxygen of the air, transports it through the vascular system into the heart, arteries and capillaries, distributing its oxygen to the elements of the tissues. In this exchange between the blood and the organic elements, which represents the interstitial respiration, the constitutive principles of the tissues oxidize at the expense of the hemoglobin, which, yielding to them its oxygen, is itself reduced. This reduced hemoglobin, which gives the venous blood its dark color, is brought back to the lungs to make a new supply of oxygen necessary for life. The amount of oxygenated hemoglobin or oxyhemoglobin, in the state of health, varies between 12 and 14% of the weight of the blood; moreover, the richness of this oxyhemoglobin humor corresponds to the weight of iron and is proportional, not only to the number of globules, but also to their volume.
In anemic patients, the amount of oxyhemoglobin decreases; it is 10.9, 8.7%, depending on the degree of anemia, but can fall to 4% and even less in cachexia; on the contrary, it rises to 15% in the plethora. Spectroscopic examination of hemoglobin, when studying undiluted, pure blood, under varying thicknesses and graduations, in a hematoscope, demonstrates several absorption bands in the spectrum, which distinguish oxyhemoglobin from hemoglobin. reduced hemoglobin and its various derivatives. In summary, the characteristic phenomenon of the two bands, located in the clearly defined yellow and green beaches, easy to define and measure, serves as a basis for hematospectroscopy.
The amount of oxyhemoglobin is measured by the spectroscopic analysis of a few drops of blood placed in a small capillary vessel called a hematoscope. It is also by means of the spectroscopic examination of the blood circulating in the thumb that one appreciates the activity of the reduction, that is to say the time necessary for the oxyhemoglobin to be reduced in the tissues, abandoning to cellular elements the quantity of oxygen which it contains, a phenomenon which constitutes interstitial respiration, a phenomenon of gaseous exchange between blood and tissues. The activity of reduction in physiological conditions varies within certain limits. This activity is increased by efforts, walking, climbing, gymnastics, horse riding, fencing, cycling, provided you do not reach the excessive fatigue and overwork that lead to slower trade.
It is permanently reduced in certain diseases, such as anemia, chlorosis, cancer, etc. It can be regularized for an appropriate medication. The evaluation of the quantity of oxyhemoglobin and the activity is done by the hematoscopic method which bears my name.
Changes in oxyhemoglobin reduction activity in the Eiffel Tower climbs
I took more than 60 observations by varying them in order to study the effects produced: 1st by mechanical ascension in elevators; 2nd by climbing up the stairs at various heights; 3rd by walking down the stairs
Climb stairs
The observations are 28 in number. The details are in the form of Table 1. As an example, we reproduce the results of one of the ascents practiced on August 24, 1889.
These observations and all those shown in the table show that in individuals with different amounts of oxyhemoglobin and variable activity, the increase in activity is a constant fact. Another observation demonstrates the persistence of increased activity for two hours at 285 m and even after the descent.
The details of all our observations are given in Table No. 1 which includes the results of 28 observations of elevator ascents.
Let's look at the general conclusions that result from the study of the big picture:
- Of the 28 cases, the activity is increased 26 times
- There are only two cases of decreased activity, and still very small (0.18 to 0.15), and it must be attributed to a moral influence (vertigo or nervous state). The increase can therefore be considered as the rule. It ranges from 0.08 to 0.54; the average is about 0.28 (it reached exceptionally 1.15 in an observation, # 23)
Activity of the reduction in the climbs
As an example of the phenomena produced in the climb on foot, I reproduce three observations that were taken on June 26, 1896 following a lecture made at the Tower in the presence of Professor Proust and his students of the Cours d'Hygiene à la Faculty of Medicine, numbering 80.
In these three observations, we note a very significant increase in activity of 0.20, 0.34 and 0.45, in other words a quarter, a third, and more than half of the activity taken in the past. departure. The study of Table 2, which summarizes 26 observations of climbs, will allow to appreciate the variations which occurred in the various circumstances.
In examining this table from the point of view of the activity of reduction, we find that it has been diminished only in four out of twenty-three cases. On the contrary, it has been increased in all the others (19 cases). The increase in activity is therefore the rule. The decrease occurred only in cases of shortness of breath, that is to say, overwork due to the effort too fast or too intense, which is also observed in all the exaggerated physical exercises.
The increase in activity is about the same as for the climb in elevators, although having a tendency to be higher. It varies from 0.04 to 0.60; it is on average 0.29. The minimum of 0.04 coincides with a certain degree of breathlessness. The two maxima 0.55 and 0.60 coincided with prior ingestion of concentrated coffee. It therefore seems that one conclusion is necessary: in the passive ascent, the increase is certainly due to the influence of the rapid change of the medium, whereas in the active ascent, the work produced and the muscular exercise give an increase, but it is not as pronounced as one might suppose. The influence of the surrounding environment alone seems to be of nearly equal importance to that of the expenditure of muscular energy, combined with that of the medium. These two influences do not necessarily act in the same direction, as is proved by the few cases in which the diminution has been observed. This is one of the reasons why it was not possible for us to find a relationship between the mechanical work produced by the climb and the increase in activity. These studies would need to be continued and done on a much larger number of individuals, and under even more precise conditions.
Downhill walk
It has been possible for us in some observations to notice modifications of the activity of the reduction in the descent on foot. Here is the summary table of these observations:
In another observation (No. 14), the descent was 20 minutes without causing shortness of breath and without significant acceleration. In two other cases of ascension on the 2nd floor (N ° 51 and 53), the descent was carried out in 5 minutes, without breathlessness, but with a feeling of fatigue mainly in the muscles of the calves and the right anterior of the thigh. (The climb lasted a quarter of an hour.) Looking at this chart, we find that in the first three observations, where the previous climb had lasted 45 minutes, the descent lasted only 25 minutes. The pace, moreover, had not been settled in advance; but in all three cases there is an increase of the activity of the superior reduction even to the increase produced by the rise, that is, 0.25 + 0.42. Moreover, in the third case, the rise having produced fatigue and shortness of breath, the activity was, at the summit of the Tower, diminished by 0.12. On the contrary, after the descent, the activity was increased by 0.24. In the last two observations, the descent took place in 5 minutes, while the climb took 15 minutes.
These results seem to lead to this conclusion, at least for this small number of observations, that the fatigue due to the physiological work of the descent, which is mainly due to the extensors of the foot and the leg, is ie, the calf area and the upper part of the thigh, results in an increase in the activity of the reduction greater than that produced by the ascent and even added to it. These conclusions would, moreover, be in agreement with the observations made in the daily practice of the work at La Tour, as we have explained elsewhere.
Pulse modification
Mounted by lifts
The pulse changes do not show the constancy of the increase observed for the activity of the reduction. The decrease was observed in 6 cases out of 17 observations. On the contrary, the increase seems much more usual. Indeed, in 11 out of 17 cases, these increases were from 2 to 8 and very exceptionally from 11.
Mounted on foot
On the contrary, in climbs on foot, the decrease was only observed twice in the same individual, despite an increase in activity of 0.34 and 0.53 (Observation 13 and 17). The increase is in the following 14 cases, ranging from 1 to 76.
From the examination of this table, it follows that there is generally concordance between the increase of the pulse and that of the activity.
Vascular tension
In a first ascent with Dr. Potain who wanted to study the action of the ascension on the pulse of his students, we obtained the following results on two subjects: Dr. Segond and Dr. H. The tension is there expressed in centimeters of mercury.
A third observation was made by Dr. Porge on a walk up to the 2nd platform in 15 minutes.
It is noted that the increase in tension was more pronounced in passive ascents at 300 m than in the climb on foot. In these observations, the blood pressure was taken using the sphygmomanometer and following the method of Professor Potain, by the professor himself and by Dr. Porge.
Changing breathing
The variations in the number of breaths are very irregular. Whatever the mode of ascension, we usually observe a slight decrease of 3 or 4 breaths per minute, but almost as often equality. The increase seems to be exceptional. This absence of accentuated results can be explained by the difficulty of the precise evaluation of the number of breaths in a rapid examination and subordinated to the auto-suggestion of the observed subject. However, in general, breathing has shown a noticeable increase in the amplitude of inspiration.
Conclusion
It follows from all these observations and their study from the different points of view that I have considered, that the characteristic of the influence of the ascents to the Tower without any work, and consequently the action especially due to the rapid transport, is the very noticeable and almost constant increase in the activity of the reduction.
This increase is, it is true, found in climbs in funiculars, on high mountains; but it does not happen here at a thousand meters or more, but at the mere height of 300 m.
In the funicular ascents at Glyon (742 m), Murren (1,673 m), Righi Kulm (1,800 m), I observed differences as little as 0.10 , that is to say, lower than the average increases observed at the Tower. It is therefore necessary to admit a special action in relation to the position of the isolated tower of the atmospheric layer in contact with the earth. At the top of the Tower, one would thus be in a sort of climate comparable to that of much higher mountains; and besides, the meteorological observations prove well for the variations of the aeration, the temperature, the radiation and the mode of the winds, as well as for the electric tension of the atmosphere, a similar analogy with the variations observed on very high mountains. This results from work of the same kind, previously reported in this book.
It is permissible to draw a conclusion from a therapeutic point of view: it is that the influence of ascension is favorable in all morbid states where there is an indication to excite the activity of reduction. for example, in the first place, in anemia, chlorosis, certain dyspepsia, etc.
This opinion, expressed by several doctors, that we could use the stay of the 3rd platform for a therapeutic purpose, that is to say to install a kind of altitude cure, was reasonable. . As a matter of fact, the staff, and especially the women employed in the establishments of the various platforms, and even in the men suffering or convalescing, have noticed a marked improvement in the general condition, especially the increase of the appetite and regularization of the general nutrition activity.
It would be interesting to consider these results in altitude cures to which could be added an easy mode of rapid and repeated climbs on summits as abrupt and isolated as possible, where one would be under the the influence of an atmosphere quite special and very different from the neighboring layers of the soil, however high it may be.
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