The passing reference to Exner was not just an aside. The editor of the Annals of Hydrography and Maritime Meteorology had sent Wegener Exner’s recently published Dynamische Meteorologie for review. Wegener had agreed to review it, writing to Köppen that “he liked the book, and this has produced a charitable compulsion to read carefully. ‘Charitable’ because it helps overcome my aversion to his very abstract treatment.”67 If he read Exner’s book with a certain benevolence, that benevolence did not spill over into the review, which damned with faint praise and praised with faint condemnations. In 1911 Exner had accused Wegener of producing a book (Thermodynamics of the Atmosphere) that was incomplete, of mixed quality, seemingly composed of whatever the author had been reading at the moment, and in any case something that would not last more than a year or two. Here Wegener returned Exner’s favor, albeit without the haughty demeanor and biting tone.
Wegener’s review of Exner’s book began by announcing that most of the major topics covered and major findings had already appeared in a 1912 encyclopedia article in the Encyclopedia of Mathematical Sciences which had not reached its intended audience because reading it required the purchase of the entire volume. In the existing literature, Wegener continued, Exner’s book most closely resembled the work of William Ferrel and Adolf Sprung, mathematically updated, with special attention to Exner’s own work and “even more attention to the work of [Max] Margules, which in the words of the author [Exner] ‘is woven through the book like a red thread.’”68 So, suggested Wegener, the book mostly resembles textbooks of weather science characteristic of the later nineteenth century, with updated mathematics: an antique approach to the subject, with some new mathematics, fronting the work of the author, but depending throughout on another scholar’s conception of the subject.
The book, Wegener continued, was very much like the work of Bjerknes: a purely theoretical treatment of the subject matter, not based in observations, in sharp contrast to the work of Teisserenc de Bort and Hildebrandsson’s Les bases de la méteorologie dynamique, which took these foundations not to be mathematical principles but observations, and which was organized historically rather than theoretically. While there is some treatment of thermodynamics in the works of Exner and Bjerknes, said Wegener, it stands in sharp contrast to his own view of thermodynamics, where thermodynamic principles are introduced to explain the observations and not the other way around. In both Exner and Bjerknes, the relationship is rather like that of experimental physics to theoretical physics: the only observations of the atmosphere they discuss are those they can explain by current thermodynamic principles. In a more complete treatment of the phenomena, there would also be mechanics, acoustics, radiation, electricity, and the optics of the atmosphere. This sort of work would be an applied physics, “while Bjerknes and Exner provide instead applied mathematics, the first in the form of a single large theory, the latter more referential in form as a collection of important mathematical-theoretical investigations.”69
The great utility of Exner’s book, from Wegener’s standpoint, was that it demonstrated (largely through the author’s admission in the later chapters) that the problem of atmospheric dynamics was very far from a solution. Exner’s clear presentation of the main lines of mathematical theorizing showed the difficulty of trying to harness meteorology to preexisting mathematical structures of theoretical physics or laboratory investigations alone. This, of course, was Wegener’s standpoint from the beginning of his career in meteorology. In his book on Thermodynamics of the Atmosphere he had insisted that we move from the treatment of thermodynamic processes in ideal gases to those processes in a real atmosphere. He had insisted that the state curves of the atmosphere predicted by theory surrender to the state curves demonstrated by observation.
We can see now that Wegener was removing the study of turbulence from his list of “67 topics” because the approach taken in the literature of meteorology was moving away from the empirical materials necessary to build the atmospheric physics that would be the bridge between pure theory and pure observation. Exner’s book, the predilections of the editors at Meteorologische Zeitschrift, the theoretical work of his good friend Bjerknes, and even the orientation of his father-in-law and closest collaborator all pointed to meteorology as the science of atmospheric dynamics in the troposphere, aimed first and foremost at understanding the genesis and history of midlatitude cyclonic storms. Wegener, on the other hand, was devoted to a much more phenomenological viewpoint: “meteorology” was the study of everything that happened in the atmosphere from Earth’s surface to the outermost layers, and meteorological phenomena were any phenomena that helped to understand the physical characteristics of that atmosphere, irrespective of the discipline to which such phenomena seemed to belong.
Wegener’s conception of meteorology was not quite as broad as that of Aristotle, but nearly so. If we consider that he was also actively at work in geology, geophysics, and climatology, through his work on continental displacements, then in some sense his science was equivalent to Aristotle’s “meteorology,” which held all these things within its ambit. This created a very serious problem for the kind of work he wanted to do.
The partitioning of meteorological research in the early twentieth century, and indeed of research in most fields of science, is closely documented in the multiplication of journals. Within meteorology in Germany there was Das Wetter, largely anecdotal reporting of interesting weather phenomena and qualitative discussion of their patterns; there was Meteorologische Zeitschrift, with its predilection for study of weather from both a practical and a theoretical standpoint; and there was Aßmann’s Beiträge zur Physik der freien Atmosphäre, invented specifically to provide an outlet for studies of the atmosphere not pertinent directly to weather.
While Meteorologische Zeitschrift occasionally permitted Wegener and others to publish short notes on studies of the upper atmosphere, a review of Wegener’s publication history (up to 1917) shows that he was repeatedly driven to physical and chemical journals not typically read by meteorologists in order to report the results of his investigations. In 1917, he could see that meteorology was moving farther away from and not closer to his broad conception of the subject. He was increasingly aware of the extent to which he was being forced to “bury” his research (his own word) in marginal publications, and he was increasingly unwilling to put energy into topics that would not find an audience.
Continental Displacements, 1917
In the midst of all this discussion of the future of meteorology, as well as Wegener’s own research and his publication plans, one might well ask, Where are continental displacements in all of this? The answer is, effectively, nowhere. At the end of a long letter to Köppen in mid-May Wegener closed with the following:
Prof. Andrée, the geologist at Königsberg (earlier a Priv. Doz. [instructor] in Marburg) sent me a long article from Petermanns Mitteilungen, a review of the displacement theory, where he takes an intermediary position. He reviews the contrary evidence put forth by Prof. Diener (Vienna), which made a scant impression on me, because he [Diener] has for the most part misunderstood me. In one place he has mistaken a position on the globe by 90°! Articles by Soergel, Semper and others have appeared in the same vein—all unknown to me—and Dacqué, the author of a substantial paleogeography, has written to me that he will fire off a review of the various recent “anti-Wegener.” Best regards, Alfred.70
The author of this article, Karl Andrée (1880–1959), was an acquaintance of Wegener from Marburg and a protégé of Emanuel Kayser (as was Hans Cloos). Andrée, no relation to the celebrated cartographer, had taken his PhD in Göttingen in 1904, and in 1917 he was a professor (a wartime “Extraordinarius,” like Wegener) of geology and paleontology at Königsberg. The full title of his review was “Alfred Wegener’s Hypothesis of the Horizontal Displacement of Continental Blocks, and the Permanence-Problem in Light of Paleogeography and Dynamical Geology.”71
That Wegener showed no inclination to study or r
espond to this article in 1917 does not make it any less significant a part of his life story. It was the first extensive review of his work in a leading earth science periodical which was not an outright attack or an outright defense. It was influential in framing the terms of the debate in Germany on Wegener’s work for some time to come. The issues Andrée chose to address, as well as those he did not address, would turn out to be of some importance for Wegener at a later date. This is to say that if Wegener had a strong influence on Andrée in the conventional sense that we speak of one thinker being influenced by another, Andrée influenced Wegener by helping to determine the way in which he was read and understood by German earth scientists. We will return in a moment to a consideration of Andrée’s critique of Wegener’s hypothesis of continental displacements, but first we must consider Wegener’s situation in May and June of 1917.
Even had Wegener wanted to engage with the question of displacements in spring 1917 (and he clearly did not), there was no time. He was immersed in plans to produce a cloud atlas with Mylius, who was so excited about the project that he had crated and shipped 400 watercolors of cloud forms to Marburg, so that Wegener might go through them with Köppen—should Wegener obtain leave.72 Alfred had also promised Kurt to look through the latter’s manuscript “Vom Fliegen” on the prospect for scientific research after the war using fixed-wing aircraft.73 He was also still running Field Weather Station 12; his regular duties as station commander, though not onerous, were real and continuing even with the stabilization of the western front.
Jüterbog
On top of all this, Wegener learned in June that he would be ordered home to Germany in early July 1917 to take over a reorganization of the Domestic Weather Service. The central office, the Hauptwetterwarte der Heimat, was headquartered at Jüterbog, a picturesque old town 65 kilometers (40 miles) southwest of Berlin. Gustav Hellmann, head of the Field Weather Service, had engineered this transfer and promotion. Hellmann had assisted Wegener in finding accounts of tornadoes and waterspouts for his book and had tried to find money to publish Else’s translation of the account of the crossing of Greenland; Hellmann admired Wegener as an excellent officer with outstanding organizational skills. Their collegial relationship and coinciding interests made Wegener a natural choice for this job, and Hellmann’s choice reflects Wegener’s growing reputation and importance as a meteorologist.
This pressure to reorganize Germany’s domestic weather service in time of war may seem odd, but it was driven by the need to accommodate military and civilian aviation, which had grown rapidly since the beginning of the war. Kurt and Alfred had often discussed the need for accurate forecasts of the wind for the use of pilots; forecasting wind speed and direction had been one of the principal tasks at Field Weather Station 12. Alfred had known since his Greenland observations in 1906 that the direction and velocity of the wind even 10 meters (33 feet) above the surface could be very different from the surface wind, and that the prevailing wind half a kilometer aloft would be different still.
This need for wind forecasts in a reorganized weather service makes sense of the request from Köppen in January 1917 that Wegener advise him about the height of meteorological masts for weather stations. Now Wegener was in charge of deciding this for all of Germany: masts with anemometers mounted on them should be the same height above ground at each station, and similarly the precipitation gauges, barometers, and thermometers should all be identically shielded, located at standard distances from surrounding obstacles, and established at fixed heights above ground. All of this had to be written down and integrated with protocols for making observations and calibrating the instruments. Because much of the work was to be done by volunteer weather observers (as is the case in many parts of the world today), it was essential that the instructions be clear, simple, and direct.
All of this pointed to Wegener’s suitability for the task: he had turned ordinary college professors into research meteorologists on the western front, and he had turned deckhands and field scientists in other disciplines into weather observers while in Greenland. He understood colloquial descriptions of weather phenomena and was expert in the calibration of simple instruments. He wrote fluidly and well, and he had an enormous appetite for work.
Wegener would remain at this task all of July and part of August 1917, during which period he barely had time to eat and sleep, let alone respond to comments about a hypothesis on continents and oceans he had offered in 1912 and (somewhat reluctantly) recast in 1915. Nevertheless, the displacement hypothesis was “out there,” and on the home front it was attracting increasing attention, not least because of the serious consideration given by writers such as Dacqué, Andrée, Tornquist, and Koßmatt. While Wegener was at work in Jüterbog on forecast meteorology, his ideas were at work in a broad and ongoing discussion of major topics in geological theory. It is appropriate, then, to turn to a consideration of the wartime geological debate in which Wegener’s ideas, but not Wegener himself, took part.
The Permanence Problem
In 1912 Wegener had framed his argument about continental displacements as a way out of an impasse. According to Wegener, European geologists, in order to explain continuities in flora and fauna on widely separated continents, had opted for a version of the contraction theory in which the deep oceans were relatively recent geological phenomena created by the collapse of huge blocks of Earth’s crust. North American geologists, however, who had eagerly embraced the principle of isostasy, asserted that the deep oceans, like the continental blocks themselves, were permanent and primordial features of Earth’s crust. The continents had always been continents, and the oceans had always been oceans. Wegener concluded that the Europeans had a sound version of paleontology allied with a deficient geophysics, whereas the North Americans had a sound version of geophysics allied with a deficient paleontology that ignored strong evidence of former continuity in geology and paleontology. Wegener characterized his own work as a way to put sound paleontology and sound geophysics together.
This framing of the question injected him prominently into a major debate in the earth sciences over the permanence or impermanence of the continents and the age of the oceans. While Wegener had certainly grasped the logical importance of “the permanence problem,” he was not initially aware of the extent and contentiousness of the debate. In 1915, Edgar Dacqué had said, “Wegener himself has so far only alluded to the idea that his theory also throws new light on the ‘question of permanence’ but has not yet explained how.”74 Dacqué actually went to some trouble in 1915 to reframe Wegener’s contribution to this debate.
While the two positions Wegener had sketched out as the “European” and the “North American” positions did exist, it was not so much that Wegener mediated them, Dacqué wrote, as that he had created a third position, or a third solution to the problem of permanence. That this should be the case was because there was also a fourth position. In this last solution, the continents have always been continents, and the oceans have always been oceans. Shallow seas have sometimes covered the continents, and in general in the past the oceans were shallower than they are now. Through time, weighted down by sediment from continental interiors, the continental shelves had been pressed down and area lost permanently to the ocean. Only Australia and Antarctica were once part of a larger continent; the others had always been as they are, where they are. No attention was given to geophysics in this solution, which remained attached to the contraction theory, albeit a contraction that only had the effect of gradually creating abyssal oceans slowly through geologic time. This deepening of the oceans swamped the relatively unimportant (geologically speaking) but paleontologically vital land bridges and island arcs and archipelagoes that explained floral and faunal connections that could not otherwise be explained away.75
One can now see that the debate in the teens of the twentieth century was essentially a four-way conjugation of two variables: geophysical evidence and paleontological evidence. North Americans paid maximal atte
ntion to geophysics and minimized intercontinental flora and fauna—minimal attention to paleontology. A certain group of Europeans paid minimal attention to geophysics and maximal attention to intercontinental correlation of species of animals and plants. These were the two positions that Wegener saw himself reconciling. Actually, however, Wegener’s position was maximal attention to geophysics, combined with maximal attention to intercontinental correlation of animals and plants—maximal paleontology. As Dacqué pointed out, there was a fourth position that was opposite Wegener: this was minimal attention to geophysics, combined with an absolute minimum of intercontinental correlation of animal and plant species. All four of these alternatives, in Dacqué’s view, could be concentrated in a single point: “One can reduce the entire permanence-impermanence debate to a single question: At what point did the deep-sea come into existence?”76 Wegener’s strikingly original view was that the continental surfaces had always been continents (allowing shallow marine incursions) and the oceans had always been deep oceans—but not always in the same configuration or in the same location on Earth’s surface. The continents themselves were the necessary “land bridges,” interrupted by rifting and drifting, not by sinking either of narrow isthmian links or of broad conjectural surfaces over the bed of current oceans.
Alfred Wegener Page 68
