Although the NACA had very capable engineers, it had few men and women with advanced training in science and engineering. The disparity between the NACA professional staff, generally with undergraduate degrees in mechanical engineering, and the availability of superior research facilities had increased with the physical expansion of the NACA during World War II. The relatively low salaries paid to civil servants made it difficult to attract staff with advanced degrees in science and engineering, who found their skills in high demand after the war. Edwin P. Hartman, head of the NACA's Coordinating Office on the West Coast, wrote to headquarters to prod it to action. To Hartman, the construction of new facilities seemed profligate without a comparable effort to recruit scientific talent. "While spending millions of dollars and exerting the highest scientific skill in the design and construction of modern research facilities," Hartman stated, "the Committee appears penurious and juvenile in its apathetic efforts to provide research brains."1. Between 1945 and 1958 the NACA would struggle with the problem of recruiting highly trained individuals in a particular field and retaining its most experienced staff.
Hugh L. Dryden, named in 1947 to succeed George Lewis, symbolized the postwar effort on the part of the NACA to recruit outstanding scientific talent. He had formidable qualifications. After earning two Ph.D.'s at The Johns Hopkins University - one in physics in 1919 and the other in mathematics in 1920 - he had spent the first 30 years of his career as head of the Aerodynamics Section of the National Bureau of Standards. He had published widely on boundary layer theory and wind tunnel turbulence. As one of the country's leading aerodynamicists, he had attended the Volta Congress on High-Speed Aeronautics in 1935 with Eastman Jacobs. During World War II he had been appointed to both the National Defense Research Committee (NDRC) and to William Durand's Special Committee on Jet Propulsion. Deputy to Theodore von Karman on the Science Advisory Board's technical mission to Europe at the close of the war, he was well acquainted with the British and German contributions to basic research in high-speed aerodynamics and jet propulsion.2
Dryden shared Vannevar Bush's presumption that technology was applied science. Bush had emphatically stated in Science, the Endless Frontier: "A nation which depends upon others for its new basic scientific knowledge will be slow in its industrial progress and weak in its competitive position in world trade, regardless of its mechanical skill." 3 This statement was made with the awareness of the enormous contributions of British and German theoreticians before World War II. It was this intellectual capital which Americans, in both universities and government laboratories, were beginning to tap in the postwar period. Dryden knew that it was not enough to five off European  capital. The research laboratory provided Americans with the tools to contribute to the country's store of basic and applied science. Research was capital, a reserve, for the future. The integrity of the NACA laboratories had to be protected from undue influence from industry, whose drive for profits required them to focus on short term problems. Dryden was a quiet, religious man who believed intensely that his job was to protect the creativity and independence of the NACA laboratories under his stewardship.
Dryden knew that, without highly trained staff, it would be difficult to continue the NACA's commitment "to supervise and direct the scientific study of the problems of flight with a view to their practical solution." Missile development, the atom bomb, and radar had created a new generation of scientists. It had brought into being new national laboratories, like Oak Ridge and Los Alamos, as well as the important university-affiliated laboratories - the Radiation Laboratory at the Massachusetts Institute of Technology and the Applied Physics Laboratory at The Johns Hopkins University. After World War II, many of the national laboratories began to lose staff, who were attracted to prestigious positions in universities or higher paying jobs in industry. With a national shortage of scientists and engineers, the NACA found it hard to compete. In the 1920s and 1930s the mystique of flight had attracted talented engineers. During the Depression the security of a civil service position gave the NACA the leverage to select the cream of its applicants. Neither aviation nor the civil service had the same appeal after the war.
Addison Rothrock and other NACA staff worried about the implications of these changes. In a 1946 memo Rothrock informed Sharp that the Ford Motor Company, Standard Oil of New Jersey, General Motors, DuPont, and other companies had announced large-scale expansion of their research facilities. Locally, entry-level salaries were comparable to those of Cleveland-area firms, such as Standard Oil of Ohio, Brush Development Company, Dupont, Thompson Products (later TRW), and the Weatherhead Company. However, these companies could offer appreciably better salaries to attract NACA engineers in the higher professional grades. 4 Between 1945 and 1956 this problem would plague their efforts to recruit and retain personnel. In 1951 John Victory submitted the first draft bill to the Bureau of Budget to alleviate this problem by exempting the NACA from some Civil Service regulations. The response of the Civil Service Commission was not sympathetic. It argued that the preferential treatment of the NACA would allow it to pirate personnel from industry and other agencies, a practice that might jeopardize the programs of the Department of Defense. In 1955 Dryden gained the support of the Industry Consulting Committee by pointing out that the staffing of NACA wind tunnels (completed under the Unitary Wind  Tunnels Plan) was inadequate because of the personnel ceiling fixed by Congress. In Dryden's view, however, the ceiling on salaries in the civil service categories was even more damaging to the NACA, which was losing key personnel and could not find replacements without salaries commensurate with those of industry. Not until 1956, as the NACA period was drawing to a close, would the NACA finally obtain legislation for competitive compensation.5
In the early postwar period the laboratory had to cope with this shortage of research brains by falling back on its own resources. Its strategy was to ferret out talent from within. The "big switch" of 1945 to research in jet propulsion hastened the exodus of experienced staff, but they were the very men who had been tied to the old piston engine technology. Because turbojet, nuclear, and rocket propulsion required the shaping of a new community of practice, the relative inexperience and youth of the remaining staff was an advantage. They were flexible and eager to prove themselves, and reorganization caught their imaginations. Walter Olson recalled, "A number of us did not think that we were even going to stay and work for the government. The war was over. What were we going to do now? But then we reorganized. You get a new responsibility and some new challenges and you say, 'Well, I win try that! Next thing you know you've spent a lifetime." 6
Jet propulsion represented an educational challenge. Surprisingly, in the early postwar years, the Case School of Applied Science, located on the east side of Cleveland about 20 miles from the laboratory, played only a minor role in the effort to prepare the staff for the new theoretical demands of jet propulsion. The reputation of Case (renamed Case Institute of Technology in 1947) had been one of the selling points in the NACA's acceptance of the Cleveland Chamber of Commerce invitation in 1940. However, unlike the close connection between the California Institute of Technology (CalTech) and the jet Propulsion Laboratory, or the NACA Ames laboratory with Stanford University, the intended bonding between Case and Lewis Laboratory had only partial success. Work in aeronautics had begun auspiciously at Case in the 1930s under Paul E. Hemke, a Ph.D. from The Johns Hopkins University. He came to Cleveland from Langley after the unpleasant experience of attempting to work under the autocratic German theoretician Max Munk. During Hemke's tenure in Cleveland, Case had built a low-speed subsonic wind tunnel. In 1935 Hemke recruited John R. Weske to found a graduate program stressing fluid mechanics and aeronautics. Weske, a student of Lionel S. Marks at Harvard University, had worked with his professor to produce the first axial-flow compressor based on the isolated airfoil design theory, an approach that later came into standard use by American designers. 7 During World War II, Hemke left Case to found Rensselaer Polytechnic Institute's program in aeronautics and later became Dean of Faculty. Weske hung on at Case with minimal support for new facilities until 1944, when Case temporarily abandoned work in aeronautics because of the loss of students and faculty swept up by the draft or lured by new opportunities offered by the expansion of industry and government laboratories.
The Cleveland laboratory could not wait for Case to rebuild its aeronautics program. Within the Wind Tunnels and Flight Division, Abe Silverstein created a Special Projects Panel to attract badly needed analytical talent from other divisions. Although theoretical aerodynamics could not be strictly viewed as related to propulsion, Silverstein recognized that the problems of jet engines were also related to supersonic aerodynamics, where the design of the inlet was particularly susceptible to the special conditions created by flight at supersonic speeds. According to former staff member Eli Reshotko, who later joined the Case' faculty, Silverstein strongly believed that,  in addition to the more applied work, research at more fundamental levels ought to be supported.8
Silverstein asked John Evvard to head the Special Projects Panel because he was one of the few staff with an advanced degree in physics. Evvard had written his Ph.D. thesis at CalTech on ion bombardment using mass spectroscopy. Within the division, Silverstein organized study groups that met weekly, often on Sunday evenings. One group humorously called itself Brutsag, the reverse abbreviation of gas turbine. The other group claimed the name of Cinosrepus, or supersonics spelled backward. A staff member selected a research topic and reported to the others "so that he could bring the others up to the level that he had reached."9
Silverstein asked Evvard to begin his work in supersonics by preparing a report on Allen Puckett's linearized theory for three-dimensional supersonic wings, When Evvard objected that he did not know anything about supersonics, Silverstein replied that it was new to everyone else too. He handed Evvard a copy of Pucketts' paper as Evvard left for a laboratory-sponsored trip. Evvard read it on the plane. After the presentation of his report to the members of the Special Projects Panel, Evvard continued to think about Puckett's theory. It appeared to be superior to that of the German aerodynamicist Ackeret, who had dealt with two-dimensional wings at angle of attack, Puckett's supersonic wing theory allowed the wing to be contoured; it could have any plane shape, but required supersonic leading edges. Evvard thought that the theory could be extended to include wing tip regions with subsonic leading edges. He was able to set up an integral equation that greatly simplified the original theory. This paper established his reputation and was the foundation for the future work of Lewis Laboratory in supersonic aerodynamics. "After I came up with my wing tip theory for supersonic wings," Evvard recalled, "we mustered a sizeable effort in supersonic aerodynamics to capitalize on the breakthrough."10
Evvard's simple but elegant solution to the problem of thin, finite wings stimulated other members of the division. Wolfgang Moeckel, who later took charge of the Theoretical Section of the Supersonic Propulsion Division, tackled the design of a supersonic inlet. What was the best aerodynamic shape to ensure the smooth passage of air into the engine? He carefully studied the work of Herman Oswatitsch on the spike inlet before beginning his own work, which soon went beyond that of the Germans. In general, early supersonic work at Lewis Laboratory focused on various types of diffusers and the inlets for supersonic ramjets."11 By 1947 the workers had developed from a group of novices in the field into a research team that made significant contributions to supersonic wing theory, despite complaints from Langley that the Cleveland laboratory should stick to propulsion.
In the late 1940s, through its own efforts, the laboratory had established a reputation in areas such as supersonic aerodynamics. In 1949 Evvard was able to persuade Franklin K. Moore to join his staff. Moore had worked at CalTech under William Sears, one of Theodore von Karman's outstanding students. Moore's contributions to three-dimensional and unsteady boundary layer theory stimulated others to tackle theoretical problems. By the early 1950s, papers by Leroy Turner, Herbert Ribner, William Perl, Clarence B. Cohen, Wolfgang Moeckel, Harold Mirels, and others established Lewis Laboratory's reputation for basic work in supersonic aerodynamics.
The basic outlines of some fields necessary to advance engine development were only beginning to take shape in the 1940s. For example, tribology - the study of friction, lubrication, and wear - did not yet exist as an engineering discipline when Langley hired Edmond Bisson in 1939. Bisson moved with the Power Plants Division to Lewis Laboratory in 1943. During World War II, work focused on quick fixes for piston rings and cylinder barrels. However, in 1945 Bisson and  his staff were able to turn to more fundamental problems. When the nature of the work began to change, some of his staff, hired during the war, lost interest and left the NACA. Bisson wanted research people for his division. It was not sufficient to solve friction problems, for example, simply by coating a surface and testing to see how it worked. He needed people who would ask, what is physically occurring when two metal surfaces, separated by a thin film, interact? His staff needed knowledge of boundary layer theory and chemistry to understand the problems of lubrication, friction, and wear. Most of the group who made the transition from the piston engine to the gas turbine engine had degrees in mechanical engineering. Bisson saw the need to make the Division of Lubrication, Friction, and Wear more interdisciplinary. He looked for people with different backgrounds in science, and he hired carefully.
Bisson's division had two branches, one for lubrication fundamentals headed by Robert L. Johnson and the other to study bearings and seals under William J. Anderson. They approached lubrication problems using both analysis and experiment. From the late 1940s through the 1960s, this division worked to establish the basic outlines of tribology. The publication of one of the first texts in the field, Advanced Bearing Technology, in 1965 by Bisson and Anderson marked tribology's coming of age as an engineering discipline.13
Between 1946 and 1952, the very years that the new fields of supersonics and jet propulsion made the Cleveland laboratory's educational needs most pressing, the aeronautics program at  Case Institute of Technology languished without support for facilities or new faculty.14 The "make-shift" equipment at Case stood in striking contrast to the impressive new facilities for research at Lewis Laboratory. In 1947, to compensate for the weakness of its program, Case offered evening extension courses leading to a masters degree. These courses were taught at Harding junior High School in Lakewood, a suburb on Cleveland's west side close to the laboratory. This saved NACA employees the trip to the Case campus. The courses were taught by either laboratory personnel (who were designated as adjunct professors) or by Case faculty members. So highly regarded were these extension courses that some Case students were motivated to drive to the west side to attend. Research for masters theses land in a few cases the doctoral dissertations) was done using the superior facilities that Lewis Laboratory could provide. Evening courses were offered on the Case campus in mathematical foundations of fluid mechanics, taught by one of the members of the mathematics department. Eugene Manganiello assumed a strong role in the organization and teaching of these courses. Manganiello had earned his bachelors degree in electrical engineering from the City College of New York (CCNY) in 1934 and his masters degree in 1935, at a time when the CCNY was extremely selective. He was typical of the bright and articulate engineering students from middle- and lower-income families that the NACA attracted in the late 1930s.
The inadequacies of the Case offerings in aeronautics were not unusual by American standards. In contrast to German technical institutes, only a handful of American universities offered formal courses in either aircraft gas turbine technology or supersonics during World War II. Suitable English texts for these subjects were not available until the late 1940s. Introduction to Aerodynamics of a Compressible Fluid by W H. Liepmann and A. E. Puckett was published in 1947, about the time that courses in supersonics in a few universities (like CalTech) began to be offered. For the study of gas turbine technology, Aurel Stodola's Steam and Gas Turbines, published in translation in 1927 and reprinted many times up to 1945, was all that was available. This was a comprehensive work on all facets of steam turbine technology; it included some theoretical discussion of the subject, but focused on turbines made by specific companies in the field. The section on gas turbines was short because of the lack of interest at the time the book was written. Despite its limitations, before 1948, when the Principles of Jet Propulsion and Gas Turbines by M. J. Zucrow of Purdue University filled this gap, Stodola was a basic reference for engineers. Abe Silverstein recalled studying Stodola, and a well-thumbed copy of this two-volume work in the laboratory library attests to its usefulness to the first generation of jet propulsion students. They taught themselves what they needed to know.
The continuing national shortage of engineers in the early 1950s tantalized Case Institute of Technology with the promise of new opportunities in graduate education. Case had a solid undergraduate program in engineering, but to become a first-rate engineering institution, it needed to strengthen its graduate offerings. This new direction affected its relationship with Lewis Laboratory. In 1947 the university trustees chose T Keith Glennan to take the reins of the presidency. From humble origins, Glennan had a solid engineering and business background. The son of a train dispatcher, Glennan attended elementary, high school, and college at the state normal school in Eau Clair, Wisc. With the railroad in his blood, he aspired to a career as a railroad electrical engineer. He transferred to the Sheffield Scientific School at Yale University, where he married the daughter of a well-known professor of economics. After graduation cum laude in 1927, Glennan worked for the motion picture industry for ten years as an operations and studio manager. During World War II, he concentrated on the development of sonar as head of the  Underwater Sound Laboratory at New London, Conn., operated by Columbia University for the Office of Scientific Research and Development.15
Glennan's presidency transformed Case from a small regional technical school focused on undergraduate training to a major engineering institution with strong graduate programs. He set in motion plans to overhaul the engineering curriculum and sparked a drive for faculty that ended in a 60 percent increase. Hard driving, gregarious, with a retentive memory for facts and figures, he raised $40 million for ten additional academic buildings, as well as additional dormitories.16 Glennan's vision included a strong program in the humanities to supplement the more narrow engineering disciplines. He supported interdisciplinary programs, including graduate programs in the history of science and the history of technology, and the founding of the journal Technology and Culture by former Case professor Melvin Kranzberg. To attract an impressive faculty for these programs, he won a substantial grant from the Ford Foundation.
In 1950 Glennan recruited Ray Bolz from Lewis Laboratory to head an Aeronautics Division to be set up within the Department of Mechanical Engineering. A graduate of Case, Bolz had begun his career with the NACA in 1940, first at Langley and later in Cleveland. In 1946 he enrolled in the Phaprogram at Yale University. He taught under Henike at Rensselaer while he was completing his dissertation. Bolz was the first of several Lewis staff to be drawn to the Case faculty, a group that included Louis Green, Paul Guenther, Stan Manson, Alexander Mendelssohn, Harry Mergler, Simon Ostrach, and Eli Reshotko. The presence of the NACA laboratory in Cleveland thus contributed to raising Case's standards and reputation in aeronautics. By 1950, Case had awarded 25 degrees to Lewis employees, and Lewis had provided employment for 150 graduates of Case.
In 1951, to upgrade the graduate program in aircraft propulsion, aerodynamics, and general fluid mechanics, Bolz and others at Case decided that their program could not depend on part-time students, provided to a large extent by the NACA.17 Bolz worked to build a resident program centered on the Case campus with full-time faculty teaching fun-time students. Requirements for the Ph.D. were to include one year of residency.
To continue to teach extension courses on the west side would have divided the efforts of the small faculty, since any course would have to be taught twice. The Case faculty in charge of planning the new propulsion curriculum criticized the past practice of using Lewis Laboratory personnel to teach courses: "The men teaching were competent, but full-time research jobs left little time for development of good graduate courses."18 This statement requires some scrutiny. Evvard, a Ph.D. from CalTech, for example, had credentials equal or superior to those of the Case faculty. Lewis Laboratory personnel could teach the new principles of jet propulsion with the benefit of specialized knowledge acquired through the study of theory and experimentally in the laboratory's wind tunnels. NACA engineers and scientists had studied the German documents available through Wright Field, and they had the benefit of interaction with the German pioneers of the caliber of Hans von Ohain and Anselm Franz. In contrast to this large and supportive engineering community at Lewis Laboratory, in 1952 Case had an Aero Division that consisted of only three full-time faculty members. Facilities for research were also lacking until the late 1950s, when Case completed a jet Propulsion Laboratory.
Although it wanted to drop the west side extension courses, Case hoped to keep its talented pool of part-time students from Lewis Laboratory. It instituted a program of late afternoon classes on the Case campus that full time resident students, as well as NACA, Thompson Products, and other industry employees could attend after work. The laboratory personnel who had previously  taught the extension courses turned over their lecture notes and course outlines to the Case faculty. The end of their formal connection with Case, in Eugene Manganiello's view, marked the end of the school's dependence on the NACA for the most advanced knowledge in the field. "This is an example where the schools, partially because of the national security restrictions, were unable to keep pace with a rapidly advancing technology. Our efforts in this regard were designed to assist the college until such time as it was able to incorporate this advanced material into its own curriculum."19
On a graduate level, Case now could offer five courses in incompressible, compressible, and viscous flow theory; three aircraft propulsion courses: aircraft propulsion principles, compressor and turbine theory, and advanced gas turbine power plant design; and one course on the dynamics of aircraft and missiles.20 The new arrangement meant that Lewis employees now had a 45-minute commute after a day of work. Although some laboratory personnel did make the journey to the Case campus to complete their degrees, the new, more stringent Case policies had the effect of encouraging Lewis personnel to look to more prestigious institutions when they considered graduate work. When a division head encouraged a staff member to go to graduate school, he (or, in very rare cases, she) often passed over Case in favor of Brown, Columbia, CalTech, Rensselaer, Cornell, the Massachusetts Institute of Technology, or Cambridge University in England to spend the required year of residency. They brought the benefits of contact with faculty in these schools back to Lewis Laboratory.
The first engineers to seek advanced training did not receive any financial support from the NACA. They took leaves of absence and paid their tuition out of pocket, with the expectation of a higher civil service grade when they returned. In 1950, with the passage of the NACA-Graduate Study Leave Act, it was possible to partially compensate employees for their loss of salary. However, tuition still had to be paid by the employee. In the first year the act went into effect, the laboratory had a training budget of $10,000 for seven participants. By 1958 it had 51 participants and a budget of $31,000. Other personnel took graduate courses at their own expense. During the same period the Department of Defense could offer much more generous financing for the training of its scientists and engineers. The laboratory had to wait until Sputnik forced the passage of the government Employees Training Act in July 1958. This act provided a uniform government-wide training program. Only then was it possible to cover all the expenses of graduate education for Lewis employees.21
When Case discontinued its extension courses on the west side, Lewis formalized the seminar approach practiced since the days of Brutsag and Cinosrepus. It began a program of free, non-credit, in-house courses. These courses had the advantage of focusing on areas related to general aspects of current work at the laboratory. They fostered communication among divisions, thus strengthening an interdisciplinary approach to common problems. "Courses taught at the Lewis Center," Manganiello pointed out, "also offered an excellent means of communicating advanced concepts developed by one particular research group to others whose research activities were in broadly related fields."22
In its first year the course attracted 150 employees. John Evvard took charge of the curriculum. In 1951 the laboratory offered courses on heat transfer, taught by Robert Deissler and Simon Ostrach, who later joined the Case faculty. John Livingood, a Ph.D. from the University of Pennsylvania, taught mathematical analysis. Dr. Robert B. Spooner's course in theoretical physics, originally a Case course, also became part of the non credit offerings. Members of the staff of the Compressor and Turbine Division used a team approach in their courses in that subject, and  chemical background for combustion research was taught by members of the Fuels and Thermodynamics Division. With weekly meetings of two hours, one on the employee's own time, the courses were regarded as an important supplement to the experimental work of the laboratory. They were rigorous, with required mid term and final exams. 23
The imprimatur of an advanced degree did not necessarily guarantee that a particular individual could be useful to the laboratory. As Walter Olson, then chief of the Combustion Branch, explained, "A professor nurtured in academia would likely not have encountered and diagnosed the physical problems involved in the new types of propulsion systems."24 Educated at Case at the end of the Depression, Olson had gone to work for Lubrizol, a Cleveland-based company that made oil additives. Since much of the Lubrizol research was being carried on at Case in Carl Prutton's laboratory, Olson remained at Case to earn his Ph.D. in chemistry and chemical engineering in 1941. He was well acquainted with the pace and prerogatives of academe. When he looked back on the engine situation after World War II, he explained that a formal degree program did not always meet the needs of those who were deeply immersed in the perplexing problems of jet propulsion. His remarks highlight the sense of urgency and impatience to get results in the Cold War atmosphere of the late 1940s. National security concerns shaped the research programs of government laboratories. "We were trying to get into specialties fast. We needed to get out to the cutting edge and sometimes it was more useful to bring in a specialist in a particular field."25
Ernst Eckert was just such a specialist in heat transfer - a scientist who had worked at the Luftfahrtforschungsanstalt (LFA), the German laboratory for basic research at Braunschweig during World War II. Presented with the opportunity to bring him to Lewis Laboratory, Abe Silverstein, the laboratory's new Chief of Research, lost no time in seizing it. Eckert accepted a generous offer from the NACA and left Wright Field for Cleveland in 1949. He brought to Lewis Laboratory knowledge and experience of basic work in Germany in jet propulsion and, more important, a new approach to the problems of heat transfer. It was through his role as a teacher at the laboratory and later at the University of Minnesota that Eckert personally reinforced the American synthesis of advanced German work in heat transfer begun by Wilhelm Nusselt and his successor, Ernst Schmidt, at the University of Munich.26
By training and experience, Eckert's background contrasted with that of his American colleagues, who struggled to find ways to acquire advanced training comparable to that available in Germany before World War H. He completed a Ph.D. in mechanical engineering at the German Institute of Technology in Prague in 1931. Intrigued by photographs of turbulence and separation of flow of heat, in 1934 he chanced upon Abriss der Stromungslehre, Ludwig Prandtl's introduction to fluid mechanics. This was a turning point in his intellectual development. It required a leap of the imagination to see that Prandtl's boundary layer theory could be applied not only to the flow of air over the wing of an airplane but also to the complex processes involved in the transfer of heat. After study with the well-known expert in radiative heat transfer, Ernst Schmidt, at the Institute of Technology in Danzig, in 1937 Eckert followed Schmidt to Braunschweig, where Schmidt was head of engine research.
In Germany basic and applied research were kept physically separate. Applied research was carried on near Berlin at the Deutsche Versuchsanstalt fur Luftfahrt (DVL). The concentration of more basic research at Braunschweig allowed considerable interaction between theoreticians involved in engine research and those in other disciplines, particularly fluid mechanics. In contrast,  the NACA had isolated its engine research at one location, preventing the fruitful exchanges with aerodynamicists that Eckert had enjoyed at Braunschweig. Adolf Busemann, Herman Schlichting, and Ludwig Prandd (at nearby Goettingen) were his colleagues. These associations reinforced his awareness of the importance of fluid mechanics in the study of heat transfer. His book, Warme und Stoffaustausch, applied Prandtl's boundary layer concept to heat transfer problems; it was not published in 1944 as he had expected, because Allied bombing repeatedly destroyed the plates for the book. In 1940, almost immediately after Hans von Ohain had demonstrated the feasibility of jet propulsion, Eckert's Division of Thermodynamics dropped piston engine research and began to focus on the problems of turbojet engines. Through his research using an optical instrument developed in the late 19th century - the Mach-Zehnder interferometer - to study heat transfer, Eckert began to lay the theoretical basis for turbine cooling.27
Eckert was among the 260 scientists and engineers invited by the Army Air Forces to come to the United States under "Operation Paperclip" in 1945.28 At Wright Field Eckert joined Hans von Ohain, Theodor Zobel, Anselm. Franz, Helmut Schelp, Alexander Lippisch, Eugen Ryschkewitsch, and others who had been doing advanced work in high-speed aerodynamics and jet propulsion in Germany. At the expiration of his one-year contract with the Army in 1946, it was renewed for an additional five years.
Because Eckert was the first to recognize the usefulness of the Mach-Zehnder interferometer for basic studies of heat transfer, he was anxious to have one built at Wright Field so that he could continue work begun in Germany.29 The success of the American built interferometer made it a model for other interferometers at universities such as Rutgers, Ohio State, and the University of California at Berkeley in the late 1940s.
The Air Force appears to have viewed Eckert as too valuable to lose prematurely to a university. Eckert was denied permission to join L. M. K. Boelter's heat transfer group at the University of California at Los Angeles.30 However, the Air Force had a keen interest in assisting the research in jet propulsion in Cleveland, and with the funds for expensive experimental apparatus more available to the NACA than the Power Plants Laboratory at Wright Field, Eckert was allowed to become a consultant for the Cleveland laboratory. He was assigned to the Turbine Cooling Branch under Herman Ellerbrock to complete the last two years of his contract. Eckert's presence stimulated the group in turbine cooling to move beyond the foundations of heat transfer laid by W. H. McAdams in his book Heat Transmission, published in 1933.31
 When the laboratory embarked on a study of the solid and air cooled turbine blades of the Junkers Jumo 004, Eckert pointed out the limitations of Franz's method of internal air cooling. Heat had to penetrate the metal blade to reach to cooling air in the interior, a slow and inefficient process. He encouraged the laboratory to consider other methods of turbine cooling. At Braunschweig he had begun to explore potentially more effective approaches like transpiration, film, and natural convection liquid cooling. At Lewis Laboratory he continued this work. "I developed, together with members of the Turbine Cooling Branch [at Lewis], the theory of these cooling methods by analysis and furthered their development by experiments."32 Film cooling, now in general use, particularly attracted him, and he spent much of his time advocating further basic research on this method. While at Lewis Laboratory, he also worked out the theories for transpiration cooling and natural convection liquid cooling. He had begun to experiment with various methods of applying these new theories.33
Eckert's efforts to turn the opinion of the Viscous Flow Panel in favor of basic research were only partly successful. He suggested that more precise values of Prandtl numbers were necessary for high-temperature investigations and proposed a method to measure these numbers based on work he had done at Braunschweig. In a memo prepared for the panel, he suggested that a test set-up, based on the analytical relation for a flat plate, could use a cylinder to investigate the temperature relations in the gas flow. After considerable discussion, the panel agreed that Eckert's proposal demonstrated a "pressing" need, but recommended that this research be undertaken by a university.34 Exactly why Eckert failed to receive support for this basic work is unclear, but it appears that Lewis's leadership was skeptical that research at such a fundamental level would yield tangible results.
Eckert chafed at the emphasis on applications at Lewis Laboratory. Unlike the clear-cut German organization of research, which kept basic research and applications separate, at Lewis there was a shifting, never quite defined, line between them. Those who practiced on the most analytic levels were never allowed to lose sight of the connection of their research to the improvement of American engine technology. The organizational structure, which usually included fundamental and applied branches within divisions, reflected this supposition.
Testing of full-scale turbojet engines was, in Eckert's view, less valuable than work on isolated problems using scale models of components. He advocated a careful, systematic approach, working from simple to more complex experimental rigs. Eckert viewed Silverstein as a man "too eager for quick results, and not patient or meticulous enough" to allow research to proceed in a careful and rational manner from simple turbine wheels consisting of one stage, through models of several stages up to full-scale testing.35 Silverstein was willing to skip steps to reach the hardware stage, where full-scale testing took over. He could never see research as an end in itself. Eckert did not feel that the role of a research laboratory was to design engines or components. Although Eckert was allowed to set his own research agenda, he did not have an entirely free hand. He was frustrated in his desire to address the entire range of basic heat transfer problems. For example, Eckert could not work on the problem of aerodynamic heating, an interest' that he had developed at Braunschweig in connection with the supersonic flight of the V-2.
Silverstein appears to have preferred Eckert to work on calculations, rather than build expensive experimental apparatus, although he did authorize the construction of several large turbine wheels for Eckert to continue his work on natural convection liquid cooling after Eckert had....
 ....worked out the theory with a Lewis mathematician, Thomas W Jackson. Why a Mach-Zehnder interferometer for heat transfer studies was not built at Lewis Laboratory is not entirely clear, but it seems that Eckert's personal research interests were viewed by Silverstein as subordinate to his role as mentor to the capable, but not as highly trained staff at Lewis. Robert Deissler, a quiet giant in the heat transfer field who spent his professional career at Lewis, recalled Eckert's helpful attitude and his ability as a teacher to make extremely complex subjects appear simple.36 George Low, later Deputy Administrator of NASA, worked with Eckert on a heat transfer problem in connection with the design of nuclear reactors.37
Eckert stimulated the work of others both directly through work on specific problems and through his course in heat transfer. He used his text, Introduction to the Transfer of Heat and Mass, translated at Wright Field with the help of Robert Drake, to teach a seminar in heat transfer.38 After Eckert left in 1952, his book continued to serve as a text for courses in heat transfer.
Why Eckert did not press to have a Mach-Zehnder interferometer built for heat transfer studies at Lewis is not clear, but it seems that Eckert's energies were directed toward fostering analytical talent. Members of the Instruments Division built an interferometer for studies in supersonic aerodynamics, but Eckert had no contact with this work. Donald R. Buchele and Walton Howes recalled that they used the early papers of H. Shardin as a guide in building their first interferometer. By the time they could take advantage of the presence of Eckert and Zobel at Wright Field, they had perfected their instrument to a point that rivaled Zobel's German-built interferometer.39
Eckert's impatience with the applied emphasis of the laboratory, his interest in teaching, and his desire to see the field of heat transfer established as a coherent body of knowledge pulled him toward university research. When he left Lewis in 1952, after turning down an offer of an endowed professorship at Case, he established his own heat transfer laboratory at the University of Minnesota. There he built his second Mach-Zehnder interferometer.
Although his tenure at the laboratory was brief, Eckert's association laid the foundation for an extremely creative and productive group in the field of heat transfer. By the 1960s German work in heat transfer had become integrated into the general curricula of the best schools. When the strength of the heat transfer group at Lewis Laboratory was at its height, graduate schools like the Massachusetts Institute of Technology, Cornell, and Purdue had active programs in heat transfer, and Lewis staff were recruited from these programs. Robert Siegel, for example, worked under Warren Rohsenow at the Massachusetts Institute of Technology. He wrote, with John Howell, Thermal Radiation and Heat Transfer, this basic text, now in its second printing, has been translated into twelve languages.
In terms of basic research, the heat transfer group seems to have come close to the Braunschweig model. Robert Deissler recalled that it remained the philosophy of the group in fundamental heat transfer that problems should be "approached in such a way that results might have some lasting value, independent of a particular application." Although the group took up problems that could apply to aircraft nuclear propulsion, "the fact that nuclear propulsion never quite materialized as a viable scheme did not lessen the value of the research, which aided in understanding heat transfer in a variety of situations."40 The Analytical Section at Lewis Laboratory became a center for basic research on the problems of radiation, convection, and conduction, a distinction it held until the early 1970s, when government support was drastically reduced.41
 Simon Ostrach's career at Lewis sheds light on how the laboratory encouraged basic research within an institutional framework whose main focus was the improvement of turbojet engines. Ostrach graduated from the University of Rhode Island with a degree in mechanical engineering in 1944. At Lewis Laboratory he went to work under John Sanders to find quick fixes for the burned-out pistons of the Pratt & Whitney R-2800 and the exhaust valves of the Wright R-3350. William Perl, a theoretical aerodynamicist who transferred from Langley in 1944, was the laboratory's "resident genius." He served as the role model for aspiring theorists like Ostrach. Perl had designed one of the early supersonic duct tunnels at the laboratory. In 1946 he took a leave of absence to study under Theodor von Karman at CalTech. By chance, Alexander Mendelssohn, a branch chief, noticed his analytical ability. In 1947 Sanders suggested that Ostrach get a Ph.D.
Ostrach went to Brown University to study in the Graduate Division of Applied Mathematics, at that time one of the outstanding programs in the country. George R Carrier was his thesis advisor and mentor. He studied fluid mechanics under Sydney Goldstein, C.C. Lin, and Wallace D. Hayes. Ostrach recalled that his professors rejected one thesis topic after another until he heard about the thesis topic of a fellow student: the problem of gas bubbles dispersed throughout a solid material. It was a problem in heat transfer by natural convection, an individual bubble treated as a horizontal cylinder of circular cross section and infinite length. Ostrach suggested a second approach to the problem, allowing him to treat it as a boundary layer problem. This appealed to his professors because boundary layer theory was only beginning to be applied in the study of heat transfer.42 Ostrach completed his thesis, "A Boundary Layer Problem in the Theory of Free Convection," in 1950.
After graduation he was offered an assistantship at Harvard University, but the salary was low. Abe Silverstein promised him a double jump in civil service professional grade if he would come back to Lewis Laboratory. Ostrach was assigned to work under John Evvard, who informed him that workers with doctoral degrees were expected to produce 2.34 reports per year, which filled Ostrach with trepidation. Evvard gave Ostrach permission to work on buoyancy flows, still virgin territory for theoretical investigation in the United States. He decided to simplify the problem he had tackled in his thesis by examining free convection about a vertical flat plate. He solved the problem deductively with the help of a colleague from another division, Lynn U. Albers, using a Card Programmed Electronic Calculator.
At one of the periodic research reviews, Ostrach presented a summary of his flat-plate theory; Silverstein exploded, "Hell, man, we're not interested in home heating!" Evvard was hardly more sympathetic. He never missed the opportunity to scoff good naturedly that Ostrach was "becoming the world's expert in a field in which no one was interested."43 Fortunately, Eckert was making his weekly Visits to Lewis Laboratory at this time. Eckert encouraged Ostrach to continue. He told him that Ernst Schmidt and W. Beckmann had solved the identical problem in 1930!
Ostrach needed a justification for his work, and Eckert may have told ' him that Ernst Schmidt had used natural convection to circulate a fluid to cool turbine blades. Ostrach began to refer to the paper he was preparing as "natural convection parallel to a generating body force" to imply a relationship to turbine cooling. "But anyhow," Ostrach recalled, "I started making all this noise about the importance of it, and I tried like hell to justify it."44 Shortly afterward, the American Society of Mechanical Engineers (ASME) accepted Ostrach's paper describing work on buoyancy flows. Coincidentally, Ernst Schmidt, then on a visit to the United States, planned to attend the meeting. Eckert asked Ostrach to accompany Schmidt on the train from Cleveland to Chicago. Ostrach  described his work and gave Schmidt a copy of his paper, not knowing what to expect. After Ostrach's presentation, Schmidt rose and introduced himself as a "pioneer in this field." He commented on the soundness of Ostrach's calculations and his approach to the problem. The Chicago meeting, Ostrach recalled, was the "beginning of a long, friendly, and stimulating relationship between US."45
Fortunately, Ostrach found another justification for his work when Ben Pinkel flagged him down for a ride on his way to the laboratory when Pinkel had a flat tire. Since Pinkel knew that Ostrach was working on heat transfer problems, he invited Ostrach to attend a meeting with Admiral Hyman Rickover. Rickover described how the early sodium-cooled nuclear reactor for submarines produced greater heat transfer in the control rods than they had expected. Thinking over the problem, Ostrach suggested that natural convection could be the cause. "I was told, in no uncertain terms, that that could not be the case since natural convection was an innocuous process and could not possibly result in such large heat transfer."46 Knolls Atomic Power Laboratory later verified Ostrach's prediction. Rickover's reactor problem provided Ostrach with material for his next paper, "Laminar Natural-Convection Flow and Heat Transfer of Fluids With and Without Heat Sources in Channels with Constant Wall Temperatures."47
Few people were interested in natural convection in the early 1950s. However, Ephraim M. Sparrow, a young Harvard University student working at the Raytheon Corporation, had noticed some of Ostrach's papers and wrote that he was interested in verifying some of his solutions experimentally. Ostrach encouraged him to come to Lewis Laboratory to work with him. Sparrow returned to Harvard for a Ph.D. and later joined Eckert and another former Lewis colleague, Perry Blackshear, at the University of Minnesota.
In the mid-1950s Silverstein created the Applied Mechanics Group within Evvard's division. This group consisted of Ostrach, Steven Maslen, Franklin Moore, and Harold Mirels, who shared the same office. Moore and Ostrach contributed to three-dimensional, unsteady boundary layer theory. Mirels and Maslen focused on acoustic screaming. In 1987 all four had achieved the highest professional distinction conferred on an engineer, membership in the National Academy of Engineering.48
It is doubtful that the theoretical work of the Special Projects Panel, the Applied Mechanics Group, and the Heat Transfer Group had a great impact on the work of the laboratory as a whole. Commitment to basic research was probably never more than 5 to 10 percent of the laboratory's resources.50 Relative to the costs of testing, which took a lion's share of the laboratory's budget,  it was not expensive. A room, a pencil, a slide rule, and computing facilities, when available, were often all that basic research required.
The influence of these men lay outside the laboratory through their NACA reports and papers in the Transactions of the ASME. Their presence at the laboratory was due in no small measure to Abe Silverstein's commitment to basic research. Like Dryden and Vannevar Bush, he believed that basic research was the nation's technical capital. Although Silverstein was more comfortable with creativity expressed in tangible objects - a new compressor or afterburner - he usually recognized the value of the theoretical contributions of people like Ostrach. A new theory was like a new piece of hardware, something on the shelf, ready if it was needed in the future.
The significance of the laboratory's theoreticians in the history of the laboratory does not lie in what they contributed to on-going work. During this period the bread and butter of the laboratory still remained full-scale testing of turbojet engines and components. Rather, what the laboratory provided to young theoreticians at a formative time in their careers was incentive to continue their educations and a nurturing environment for creative work. They stimulated each other. Beyond the publication of their papers and the recognition of their engineering peers, they were free from the demands of teaching or tangible product. Their theoretical skills were complemented by comparable mechanical ingenuity on the part of the laboratory's support services personnel. They could build a small supersonic tunnel or a test rig, or modify a computer to test their results experimentally. They were at Lewis Laboratory at a time when engineering was becoming more scientific. Ernst Eckert had modestly written in the preface to his important text, "It is the opinion of the author that a physical process is understood thoroughly only where it is possible to calculate the occurrences from basic knowledge and when these calculated results are checked by experiments."52 American engineers did not yet have sufficient theoretical tools to understand what happens inside engines as predictable physical processes. Innovation in gas turbine engines in the 1950s still came more from systematic testing of full-scale engines than the theoretical approach of Lewis Laboratory's academicians.
1. Edwin R Hartman to R. G. Robinson, "NACA Personnel Program," 6 May 1946, NASA Lewis Records, Box 34, file 200. The problem of a shortage of engineers between 1949 and 1955 is documented in Paul Forman, "Behind Quantum Electronics: National Security as Basis for Physical Research in the United States, 1940-1960." Historical Studies in the Physical and Biological Sciences, vol. 18, part 1, p. 166-167.
2. See discussion of NACA's effort to strengthen science influence in Arthur L. Levine, "United States Aeronautical Research Policy, 1945-1958:'A Study of the Major Policy Decisions of the National Advisory Committee for Aeronautics," Ph.D. Dissertation, Columbia University, 1963, p. 92-103. For biographical information on Dryden, see Alex Roland, Model Research, NASA SP-4103 (Washington, D.C.: U.S. Government Printing Office, 1985), vol. 1, p. 225-226.
3. Quoted by Edwin I Layton, Jr., "American Ideologies of Science and Engineering." Technology and Culture 17:689.
4. Addison Rothrock to Manager, "Comparison of Professional Salaries at Cleveland Laboratory of NACA with Corresponding Industrial Salaries," 12 February 1946, NASA Lewis Records 341200. "Memorandum for Manager, Report of Trip by C. T. Perin, January 19 to January 28, 1946," 18 February 1946, PB 341200. See also Robert Seldon for Manager, "Comments on Nuclear Energy Aircraft Propulsion Laboratory," 21 September 1946, NASA Lewis Records, Box 34. Overall, national laboratories lost nearly 20 percent of their staffs. See Clarence Lasby, Project Paperclip; German Scientists and the Cold War (New York: Atheneum, 1971), p. 150 and note 8, p. 308.
5. Documents describing the effort for legislation for Competitive Compensation Proposals can be found in a carton designated "NACA Documents 1913-1960," located in the NASA History Office, Washington, D.C.
6. Interview with Walter Olson, 16 July 1984. 1 am indebted to Edward Constant, The Origins of the Turbojet Revolution (Baltimore: The Johns Hopkins University Press, 1980) for defining an engineering "community of practice," and for calling attention to the discontinuity between the piston engine and turbojet engine communities.
7. Brian J. Nichelson, "Early jet Engines and the Transition from Centrifugal to Axial Compressors: A Case Study in Technological Change," Ph.D. Dissertation, University of Minnesota, 1988. On Hemke, see James R. Hansen, Engineer in Charge NASA SP-4305 (Washington, D.C.: U.S Government Printing Office, 19871 p. 93,
8. Eli Reshotko, telephone interview, 30 January 1987.
9. Interview with Abe Silverstein, 5 October 1984. Interview with Irving Pinkel, 30 January 1985.
10. Letter from John Evvard to V. Dawson, 18 March 1985. See John C. Evvard, "Distribution of Wave Drag and Lift in the Vicinity of Wing Tips at Supersonic Speeds," NACA TN 1382, 1947, and "Use of Source Distributions for Evaluating Theoretical Aerodynamics of Thin Finite Wings at Supersonic Speeds," NACA TR 951, 1950. See also Allen E. Puckett, "Supersonic Wave Drag of Thin Airfoils." J Aero. Sci. 13:475-84 and papers by Lewis personnel L. Turner, Clarence B. Cohen, Wolfgang Moeckel, and Harold Mirels, among others
11. Carlton Kemper to NACA, "Outline of Research Projects for the 18- by 18-inch and 20-inch Supersonic Tunnels at the Cleveland Laboratory," 4 October 19466, NASA Lewis Records.
12. Interview with Edmond E. Bisson by V. Dawson, 22 March 1985. See also Tribology in the 80s, NASA Conference Publication 2300, 1984.
13. Edmond E. Bisson, Advanced Bearing Technology, NASA SP-38, (Washington, D.C.: U.S. Government Printing Office, 1965). For a detailed description of Lewis Laboratory's contributions to the field of tribology, see "LeRC Contributions to Aeronautics in the Field of Tribology," undated typescript. Files of the author.
14. "Planning and Goals for Instruction and Research in the Fields of Aircraft Propulsion, Aerodynamics, and General Fluid Mechanics at Case Institute of Technology," 1952, Case Western Reserve University Archives, Case Institute of Technology Engineering Department Records, 19FL, 2:1.
15. C.H. Cramer, Case Western Reserve: A History of the University 1826-1976 (Boston: Little Brown and Company, 1976), p. 262, Glennan served as President of Case from 1947 to 1966. He took a leave of absence from Case to serve as NASA's first administrator for 29 months, from August 1958 through December 1960.
16. Cramer, Case Western, p. 63-70
17. Telephone interview with Ray Bolz, September 1987. See also "Planning and Goals for Instruction and Research in the Fields of Aircraft Propulsion, Aerodynamics, and General Fluid Mechanics at Case Institute of Technology," 1952, CWRU Archives, CIT Engineering Department Records, 19FL, 2:1
18. "Planning and Goals," CWRU Archives, 19FL, 2:1.
19. Eugene J. Manganiello and Vincent R Hlavin, "Post University On-the-job Training for Engineers:' Presentation at 1961 Annual Meeting of the Society of Automotive Engineers, 11 January 1961. 221, NASA Lewis Records.
20. "Planning and Goals," CWRU Archives, 19FL, 2:1.
21. Manganiello and Hlavin, "Post University On-the-job Training."
23. Syllibi for courses between 1952 and 1957, 296/116.1, NASA Lewis Records.
24. Telephone conversation with Walter Olson, 12 September 1986.
26. On Ernst Eckert, see V. Dawson, "From Braunschweig to Ohio. Ernst Eckert and Government Heat Transfer Research," in History of Heat Transfer, Edwin T. Layton, Jr., and John H. Lienhard, eds. (New York: American Society of Mechanical Engineers, 1988), p. 125-37.
27. See Dawson, "From Braunschweig to Ohio: Ernst Eckert and Government Heat Transfer Research," P. 125-137. E. R. G. Eckert, "Gas Turbine Research at the Aeronautical Research Center, Braunschweig, during 1940-1945," Atomkerenergie (ATKE) Bd. 23 (1978) Lfg 4: 208-211. Braunschweig is described in Leslie E. Simon, German Research in World War II: An Analysis of the Conduct of Research (New York: John Wiley & Sons, 1947).
28. For the story of the importing of German scientists, see Clarence Lasby, Project Paperclip and the Cold War Lasby incorrectly identifies Eckert as an "expert in jet motor fuels," (p. 29). Thin Bower, The Paperclip Conspiracy (Boston: Little Brown and Company, 1987) also contains inaccuracies.
29. E. R. G. Eckert, R. M. Drake, Jr., and E. Soehngen, "Manufacture of a Zehnder-Mach interferometer," Wright-Patterson Air Force Base Technical Report 5721 (1948).
30. On L. M. K. Boelter, see John H. Lienhard, "Notes on the Origins and Evolution of the Subject of Heat Transfer." Mechanical Engineering 105(6):26.
31. William H. McAdams, Heat Transmission, 2nd ed. (New York: McGraw Hill, 1942). Nine NACA memoranda on turbine cooling were published as RM E7Blla-h and RM E8HO3. Authors included W. B. Brown, Lincoln Wolfenstein, Gene Meyer, John Livingood, and John Sanders.
32. Anselin Franz, the designer of the Jumo, 004, used hollow blades in which the cooling air was ducted through passages in the blade. His Cromadur sheet metal blades contained less than five pounds of chromium and no nickel at all, an achievement that particularly pleased him. They reached production in Germany in 1944 in the Jumo, 004B. See Anselm Franz, "The Development of the 'Jumo 004' Turbojet Engine," in The Jet Age: Forty Years of jet Aviation, Walter J. Boyne and Donald S. Lopez, eds, (Washington, D.C.: Smithsonian Institution Press, 1979), p. 73.
E. R. G. Eckert, "Comments to the Draft by Dr. Virginia Dawson on the History of Lewis Research Center," 9 January 1987; and E. R. G. Eckert's notes appended to "Interview with Dr. Ernst Eckert," 13 January 1987,by Edwin T Layton, Jr.
33. See E. R. G. Eckert and John N. Livingood, "Method for Calculation of Heat Transfer in Laminar Region of Air Flow Around Cylinders of Arbitrary Cross Section (Including Large Temperature Differences and Transpiration Cooling)," NACA TN 2733, June 1952. See also E. R. G. Eckert, Martin R. Kinsler, and Reeves R Cochran, "Wire Cloth as Porous Material for Transpiration-Cooled Walls," NACA RM E51H23, November 1951.
34. This work, carried out with W. Weise, was published in Forschung auf dem Gebiete des Ingenieurwesens, vol. 13 (1942). See "Memorandum to Dr. John Evvard, Chairman of the Viscous Flow Panel at the Lewis Laboratory," 1950, 295/100.71, NASA Lewis Records.
35. "Interview with Dr. Ernst Eckert," 13 January 1987, by Edwin T. Layton, Jr.
36. Personal communications by Robert Deissler, John Livingood, and Robert Hickel.
37. E. R. G. Eckert and George M. Low, "Temperature Distribution in Internally Heated Walls of Heat Exchangers Composed of Noncircular Flow Passages," NACA Report (1951) 1022, superseded TN 2257.
38. Ernst Eckert, Introduction to the Transfer of Heat and Mass (New York: McGraw-Hill 1950); published in German in 1949; revised English edition, 1963.
39. Interview with Donald Buchele and Walton Howes, 8 July 1986. I am indebted to Mr. Howes for providing me with a copy of "Visit to Wright-Patterson Air Force Base on April 26, 1949 to Discuss Interferogram Evaluation in Supersonic Airflow." See also H. Shardin, "Theorie und Anwendungen des Mach-Zehnderchen Interferenz Refraktometers," Zeitschrift fur instrumentenkunde, vol. 53, p. 396-403 and 424 -436.
40. Personal communication from Robert Deissler, October 1986.
41. See J. H. Lienhard, "Notes on the Origins and Evolution of the Subject of Heat Transfer." Mechanical Engineering 105(6):20 26. See work by C. B. Cohen, Robert Deissler, Patrick L. Donoughe, Marvin Goldstein, John Howell, John Livingood, George M. Low, F. K. Moore, Simon Ostrach, Eli Reshotko, Robert Siegel, and Maurice Tucker.
42. Simon Ostrach, "Memoir on Buoyancy-Driven Convection," unpublished manuscript, 1989, p. 2.
43. Ibid, p. 4.
44. Interview with Simon Ostrach, 29 September 1987.
45. Ostrach, "Memoir on Buoyancy-Driven Convection," p. 3.
46. Interview, 29 September 1987.
47. NACA TN 2863, 1952.
48. In 1987 the National Academy of Engineering had 1285 members in 12 fields of engineering and 106 foreign associates. Ohio had 34 members; New York, 110; California, 328; and Maryland, 34. For Franklin Moore's papers, see NACA TR 1124, TR 1132, TN 2279, and TN 2521.
49. Interview with Simon Ostrach, 29 September 1987.
50. This is based on a statement made by Abe Silverstein to the author and Arthur L. Levine, "United States Aeronautical Research Policy, 1915 1958: A Study of the Major Policy Decisions of the National Advisory Committee for Aeronautics:' unpublished Ph.D, dissertion, Columbia, 1963, p. 97.
51. Transcript of interview with Abe Silverstein, 5 October 1984, p. 11. 52 Eckert, Introduction to the Transfer of Heat and Mass.
52. Eckert, Introduction to the Transfer of Heat and Mass.