G. H. Bryan Reviews Joukowsky

Who was Lanchester’s anonymous reviewer? 55 The most likely candidate was G. H. Bryan. There are three reasons for drawing this conclusion. First, Bryan had been involved with Klein’s mathematical encyclopedia (contributing the article on thermodynamics) and so was in a position to have come across the mention of Kutta in that work. Second, Bryan was the usual reviewer on aeronautical topics used by Nature and was later to review the second volume of Lanchester’s treatise.56 Third, there is a piece of internal evidence. The 1908 review of Lanchester broached one of Bryan’s pet themes: the dependence of aerodynamics on hydrodynamics and the more fundamental status of hydro­dynamics compared to that of the new, would-be discipline. As far as math­ematical theory was concerned, said the reviewer, “aerodynamics as applied to problems of flight does not differ from hydrodynamics” (337). This denial of the independent status of aerodynamics was taken up again a few years later in a review of Joukowsky’s work that appeared in Nature, under Bryan’s name, on February 15, 1917.57

Joukowsky had already published a German-language account of the cir­culation theory in the Zeitschrift fur Flugtechnik for 1910 and 1912.58 In 1916 a book-length exposition of Joukowsky’s seminal work, based on his lectures, appeared in French under the title Aerodynamique, and it was this that Bryan reviewed.59 The subject matter of Joukowsky’s book, insisted Bryan, was not of a sufficiently distinct character to form the nucleus of a new science— aerodynamics. It was “hydrodynamics pure and unadulterated” (465). Bryan also pointed out that there were two ways of “reconciling the existence of a pressure on a moving lamina with the properties of a perfect fluid.” One was by assuming a circulation, and this, he said, appeared to be the basis of Joukowsky’s work. The other, “which has now been greatly elaborated in this country,” was the theory of discontinuous motion. “Of this theory,” sniffed Bryan, “Prof. Joukowski’s treatment is practically nil” (465).

Bryan did not explain why Joukowsky should have discussed the discon­tinuity theory. Though Bryan still adhered to it, most British experts had abandoned it, so some justification for the reproach would have been appro­priate. Nor did Bryan say what might be wrong with the circulation theory. The absence of any detailed engagement with the theory suggests that it was simply considered to be a nonstarter and that the reviewer believed he could count on his readers’ agreement in this matter. But if this part of the argu­ment was implicit, other parts were explicit. Bryan insisted at some length that Joukowsky’s book was of an elementary nature from which little was to be learned—except, that is, by a certain class of engineer. “According to the usual conventions in this country,” said Bryan, “practical and experimental considerations regarding the motion of fluids are classified under the des­ignation of hydraulics” (465). He went on to insist that both hydraulics and hydrodynamics should form the basis of a good engineering education:

It is very important that engineering students who are proposing to take up aeronautical work should be equipped with a knowledge of the necessary hy­drodynamics and hydraulics, and Prof. Joukowski’s lectures were probably admirably adapted to the students in his classes. But the book goes only a very little way towards covering the subject-matter contained in the English treatises on hydrodynamics of more than thirty years ago, with their chapters on sources, doublets, and images, motion in rotating cylinders in the form of lemniscates and cardioids, motions of a solid in a liquid, tides and waves, and detailed treatment of discontinuous motion in two dimensions. (465)

The subjects mentioned by Bryan look suspiciously like the syllabus of an aspiring wrangler. This suspicion is confirmed when Bryan goes on to recommend that any “advanced student” revisit the standard, English trea­tises for “a thorough grounding in hydrodynamics” rather than rely on the “more superficial and fragmentary treatment of the same subject” offered by Joukowsky. Both the tone and the content of Bryan’s review suggest that Jou – kowsky’s book was not taken seriously in its own terms but was being judged as a Tripos textbook in hydrodynamics—and found wanting. It might do for the engineering students in Joukowsky’s technical-college classes, but it would not get anyone through their Senate House examinations.