Alfred Wegener

by Mott T. Greene

  Benndorf and Ficker had discussed the matter with the other two general editors of the series, Arnold Eucken (1884–1950), a physical chemist at Göttingen, and Erich Waetzmann (1882–1938), and they agreed that Wegener would be an ideal choice to replace Lummer, not least because he had worked in almost every single field covered in the book. Benndorf and Ficker asked Wegener during the meeting whether he would be willing to take it on. The coverage could be expanded so that he could himself write the articles on atmospheric optics and atmospheric acoustics.46

  This was an enormous undertaking, and whatever else Wegener decided to work on, it would likely be with him for years. On the one hand, it would slow down his plan to write a textbook on the physics of the atmosphere; on the other, it would put him in charge of a major reference book whose authors were some of the most celebrated scientists in Germany and Austria. Further, the editorial correspondence and a constant connection with the leading scientists in these fields could keep him up to date and solidify professional relationships somewhat endangered by the great distance of Graz from the rest of Germany. What Kurt had said about Graz being isolated and really good for some kinds of scientific work was true, but it made it very hard to get to libraries and to meetings.

  Before the meeting had even ended, Wegener decided to take on the job, on the stipulation that he could widen the coverage a little bit to include the physics of glaciers and the physics of the oceans. These were topics that were of great interest to him and represented both the solid and liquid states of Earth’s envelope of water; geophysics seemed incomplete to him unless Earth, its oceans, its ice cover, and its atmosphere could all be included. It had been thus in Rudzki’s text in 1909 which had so influenced him, and it is difficult in any case to imagine that a polar scientist who had also written a theory of the origin of the oceans would want to edit a textbook on “physics of the Earth” which did not contain these topics. Moreover, he had just spent the period from April through July teaching an introduction to oceanography and was aware that this work needed to be brought up to date as well; the last general textbook of oceanography in Germany had been Krümmel’s handbook from 1911. A formal letter soon came from Waetzmann, and Wegener accepted the terms, which included the expansion into glaciology and oceanography.

  Benndorf later said that Wegener had not begun any fundamentally new work in Graz but had stuck with topics he had already worked on. He said that part of the fault was that “Wegener was not spared, in the ‘handbook epidemic’ that had broken out in Germany.”47 Benndorf here was perhaps expressing remorse at having gotten Wegener deeply into a monumental undertaking, in which Benndorf was already involved. However, the Handbuch and Lehrbuch traditions, epidemic or not, were what kept Germany at the forefront of world science, especially in physics and chemistry, even while shut out of international scientific cooperation, and this was the sort of undertaking that made good use of Wegener’s monumental appetite for work. Finally, at age forty-four (really almost forty-five), he was entering that phase of his career where, as he saw it, the moral responsibility of a scientist included the obligation to write summary works for the benefit of younger investigators—exactly the sort of work that had made his theory of displacements possible.

  Back in Graz for the fall term by mid-October, Wegener began his lecture course entitled “Physics of the Atmosphere, Part 1,” already planned before he had learned about the editorship. He had designed a full year of lectures that would cover the material for his planned textbook. Beginning in the autumn of 1925, he would lecture on mechanics, thermodynamics, and radiation; for the summer term in 1926 he planned to lecture on optics, acoustics, and atmospheric electricity. The textbook of atmospheric physics, of which these lectures were the foundation, was now postponed but not canceled, and the lectures would serve the subsidiary function of organizing his thinking about these topics.48

  Immediately on returning from the meeting on the Zugspitze, he found a letter waiting for him from Berlin, announcing the death of Alfred Merz (1880–1925) from pneumonia, in Buenos Aries, Argentina. Merz was the lead scientist on the “German Atlantic Expedition,” also known as the “Meteor” Expedition, following the oceanographic convention of naming the expedition after the ship. Merz had originally wanted an expedition in the Pacific, but funds were very limited, and he had to settle for the Atlantic. It was a combined expedition, planned to last two years, which would use sonar to establish depth profiles from the equatorial regions all the way to Antarctica. In addition, it would sample water for salinity to try to trace the flow of the currents in the Atlantic at various depths, and the scientific staff would also pursue maritime meteorology.

  Wegener had been deeply interested in this expedition, which had departed Germany in April 1925. He had worked hard and successfully to get his old colleague Erich Kuhlbrodt a position on it as meteorologist.49 Kuhlbrodt eventually sent up more than 800 balloons in the course of this expedition, tracking them with the theodolite that he and Wegener had designed and built. The expedition had been much on Wegener’s mind in the summer of 1925 when he was teaching oceanography at Graz. He was extremely interested in what their profiles of the Atlantic floor would show. The expedition planned fourteen such transatlantic profiles, covering most of the coast of Africa and South America. The depth information, especially at the continental shelf margins, could be very important for his theory.

  Because Merz was an Austrian and there were many obituaries to be written, Wegener got a request to write a brief obituary for him for Meteorologische Zeitschrift, and he complied, writing a two-page appreciation of Merz’s life and work; they had met but did not know each other well.50 This was, however, not the last request that would come to Wegener concerning Merz and the expedition. Merz had been the director of the Berlin Oceanographic Institute (founded by Penck), professor of oceanography at Berlin, and head of the Oceanographic Museum. Even though the expedition would proceed without him, he would have to be replaced; the institute and the university needed a professor of oceanography.

  In November, Wegener received a letter from Albrecht Penck, asking him whether he would be interested in replacing Merz in Berlin. Penck praised Alfred as a great student of both the atmosphere and the solid Earth and wondered whether he could be enticed to add the ocean to his realm of expertise. Of course, said Penck, in addition to the professorship at Berlin he would have to run the institute, with all its administrative work, and be in charge of the outreach through the museum.51

  He already knew that Wegener had been interested in the professorship at Graz precisely because of the lack of administrative responsibility. On the other hand, Penck stressed that in Germany there was no one within oceanography who was not “merely statistical,” no one capable of moving oceanography in the geophysical direction, and this had led the search committee to look not only outside oceanography but also outside Germany for a successor.

  Penck added at the end of the letter, “I’ve heard from your father-in-law how happy you are in Graz, and I can well understand this. I myself would also love to pursue my work in the midst of the mountains. But remember that old Hann moved from there back to Vienna. The atmosphere in Graz was, for him, too isolated. He longed for a different kind of fresh air, and then found what he was looking for again in a large city.”52

  Penck’s letter was followed by another on the very next day, from Alfred Rühl (1882–1935), then an associate professor (Extraordinarius) at the University of Berlin in the Institute for Oceanography (Meereskunde) specializing in economic geography. They had been instructors together at Marburg, and Rühl wanted Wegener to know that the entire staff and faculty of the institute, as well as the Ministry for Education, were solidly behind the idea of bringing Wegener to Berlin as the director of the institute. The faculty was so excited by the prospect that they wanted to make the offer “primo et unico”—he would be the only candidate. Rühl knew, he said, of Wegener’s “horror of all administrative duties” and knew that Penck
had said these were an essential part of the job. Rühl wanted Wegener to know that these duties could be off-loaded onto others, that Merz himself had done so, and that in the last two years before the beginning of his expedition he had not been impeded in his own scientific work by his title as director of the institute.53 Rühl was very enthusiastic and pressed Wegener to come to Berlin.

  Intellectually, the offer was extremely tempting, and he actually considered it for about ten days before turning it down. Penck had been very persuasive; Wegener was deeply interested in oceanography and had just finished teaching it. Penck had hit another nerve as well: Wegener had also begun to chafe at how far Graz was from large libraries, institutes, and scientific meetings in Germany, as well as at the expense of travel and the tiresomeness of wresting travel grants from the ministry in Vienna. Nevertheless, he wrote back to both Penck and Rühl on 18 November 1925 requesting that his name not be put in nomination to replace Merz.54

  The Berlin job had many pitfalls and drawbacks, personal and professional, in spite of the intellectual stature it would have conferred and the advantages of Berlin. In the end, he used the same reasons to fend off the appointment which he had in readiness if he had been called to replace Gustav Hellmann at the Meteorological Institute in Berlin, namely, his close relationship and collaboration with Köppen. To this reason he was able to add that his parents-in-law had sold their house in Hamburg, that they were all living together in Graz, and that he could not in conscience now abandon the old pair to live alone so far away from their family. Köppen was now seventy-nine, he wrote, and too old to move again. However, he thanked Penck effusively and said, “I will not deny that your assumption that oceanography would entice me is entirely true, more true than perhaps you might imagine.”55

  With that behind him, he could turn to a very pressing issue at home: he had to teach the girls to ski. They were all three big enough now to ski cross-country, and they had proven themselves as hikers and climbers. In November, even before there was enough snow, he had them practicing the motions at home.56 That Christmas, the whole family left for a ski vacation in the Ramsau, a high plateau between the Dachstein range and the Enns Valley. It offered unusually smooth terrain for this part of the world, had many cross-country trails, and included widely spaced villages. It was a favorite with many of the Graz faculty, who decamped Graz to stay in a chalet and gather together in the evening after a day of skiing. Benndorf had never learned to ski, and although Alfred was happy to teach him, he was reluctant. So, knowing this, Alfred gave him a short “book” he had just written: “Proven Methods for Old Men to Learn How to Ski.” At fifty-four, Benndorf was only ten years Alfred’s senior, but he enjoyed the joke and accepted the challenge; he and his family accompanied the Wegeners to Ramsau that Christmas and for years afterward.57

  As winter turned to spring in 1926, Wegener found himself once again a full-time theoretical meteorologist. He was teaching meteorology and reviewing books in meteorology and geophysics—more reviews in 1926 alone than in the previous decade. The most difficult review was the one he had agreed to write of Felix Exner’s second edition of his Dynamische Meteorologie; it was a better book than the first edition, but Exner had still not been able to bring himself around to accept Bjerknes’s theory of frontal weather and of cyclones as wavelike disturbances moving along the “polar front” between the prevailing polar easterlies and the prevailing westerlies to their south. It was already clear to most meteorologists in Europe and elsewhere that Bjerknes had gone a long way toward solving “the cyclone problem.” The best Exner could say about it was that the parts of the theory he disagreed with were the work of Bjerknes, and the parts he agreed with had been provided by Bjerknes’s Austrian predecessors. There was actually a good deal to this criticism, as the animosity between Exner and Bjerknes had led the latter to be less than generous in citing Exner’s and Margules’s important work. Wegener made note of this dispute, praised the utility of the book and the superiority of the second edition over the first, made a few minor criticisms of Exner’s treatment of precipitation, and was done.58

  Wegener was willing to be gentle in the review with Exner, whom he had come to like, and to whom he felt indebted for his support in getting the job at Graz, the nomination to the Academy of Sciences, the summer vacation on the Stolzalpe, and other matters; Exner was also the editor of Meteorologische Zeitschrift. But Wegener had also to go on record, as a research meteorologist, and as a friend to Bjerknes, about his intellectual judgment of “where things stood” with the cyclone problem and with the theory of frontal weather.

  Under such circumstances, Wegener turned to his favorite method of procedure: writing a review article about recent developments in the field. He set to work to write a brief (for him) history of dynamical meteorology from the beginning of the century. The centerpiece, or main line of discussion, was the career of Bjerknes, but set in the context of his time in Leipzig and of the contributions of many Germans and Austrians to the advancement of understanding of the cyclonic storms which had been the principal aim of meteorology for more than 100 years.59

  He gave a very good and very fair summary of Bjerknes’s career and thought, illustrated with nice line drawings of cyclonic waves, and left no doubt that this was the direction that forecast meteorology would take. Without criticizing Bjerknes directly, he managed to advance Exner’s claims, by insisting that what Bjerknes was doing with his cyclone model was much more kinematic than dynamic; it concentrated on the phenomena of motion and their evolution but had not yet arrived at a clear and unambiguous treatment of the causes. Moreover, Wegener’s treatment shows that he sided with Tor Bergeron and Sandström in arguing that the evolution of cyclones was not a matter of waves on a single continuous polar front, but that breaks occurred in this front. This, by the way, had been one of Exner’s main points in his recent book on dynamical meteorology. Wegener ended his discussion by recommending Exner’s book as a good place to go to understand, in great mathematical detail, the complexities of this problem.60

  This was Wegener in teaching mode, encyclopedic mode, and Handbuch mode. Unsolved problems of meteorology were for him, at this point, less and less urgent challenges and more and more the perpetual status quo of every line of investigation—once one understood it deeply enough. Looking over the fields of science he had pursued, he could see everywhere that theoretical models always had to give way from their original beautiful simplicity to the empirical complexities the world offered. He was certainly willing to take this stance relative to his own work on continental displacements and on atmospheric acoustics (his current fascination in 1926). If he could accept this for himself, he could, in reviewing, comfortably suggest it to his colleagues as well.

  This was an important development in his intellectual life, and it is not something every theorist experiences. Both Bjerknes and Exner were still “digging in” in defense of their own personal views of a large and complex problem—Bjerknes was, as always, relentlessly self-promotional, and Exner was chronically angry at being underappreciated. It was the same sort of dispute as that on ocean circulation which had poisoned relations between Brennecke at Hamburg and Merz at Berlin. Seen from inside, the issues were life and death to these men; from outside, it could often appear as the “pathology of small differences.” Wegener saw this and took note that beyond a certain threshold of elaboration, any important theoretical idea would live or die on its capacity to generate empirical results that would, in turn, test its validity.

  He was willing—it was certainly the role of a Handbuch (or Lehrbuch) editor to be willing—to offer a number of plausible solutions as wayposts for others finding their way forward. It is notable that he championed, in this review of the cyclone model in dynamic meteorology, the work of Lewis Fry Richardson (1881–1953), a British meteorologist and author of a complex mathematical treatise entitled Weather Prediction by Numerical Process.61 Richardson had developed a series of fundamental equations which, with sufficient da
ta and computing power, would allow one, if one knew the distribution of temperature and pressure across a broad area at a given time, to calculate a new temperature and pressure map at a later time. His initial results using real data had been disappointing, but Wegener said that both the optimists and pessimists were currently overstating the case, and the technique was promising even though difficulties were formidable. One notes that these equations by Richardson are the basic foundation of all computer forecast models in meteorology today.62 Wegener’s essential focus was always Die Arbeit (the work) and how that was proceeding, much more than how his own ideas were faring.

  Nearly twenty years earlier, when Wegener had given his Antrittsvorlesung on joining the faculty at Marburg, he had stressed that meteorology alternated between periods of gathering of data and synthesis into theory. Certainly his own career had shown this sort of alternation. During the war years, especially with regard to his work on tornadoes and waterspouts, it was a matter of data gathering; immediately after the war, of experimentation. The succeeding period of 1919–1924 was quite definitely a period of synthesis.

  Now, in Graz, teaching and editing a major textbook/handbook, he was once again in gathering mode. He was working at his desk, not in the laboratory or in the field. The only empirical results he reported in his publications in 1926 were the quite ordinary sunlight intensity measurements he had made on the Stolzalpe in the summer of 1925 and a brief note on inversions based on a few photographs he had taken at the summit of the Zugspitze that autumn.63

  Continental Displacements and Climates of the Past, 1926

  The end of the summer semester in 1926 marked the end of Wegener’s second full year in Graz. His whole life was in Austria now, both during the academic year and during his vacations—winter and summer. He was more deeply involved with family life than ever before, actually taking a hand in raising his children. The life they lived together in Graz had a measured and predictable routine unlike anything he had experienced since childhood. He had been out of Austria only once—a trip to Göttingen to give a lecture—if we do not count the outing on the Zugspitze. He had given a few lectures on his theory of displacements and climate, in Innsbruck, Vienna, and Graz. All his intellectual energy from the time of his arrival had been directed toward atmospheric physics and theoretical meteorology.