BIBLIOGRAPHY

BOOKS ON VACUUM TECHNOLOGY

1. S. Dushman. Production and Measurement of High Vacuum, pp. 239, Schenectady, N. Y., Gen. El. Rev., 1922. 3 (German translation: S. Dushman. Hochvakuumstechnik J. Springer. Berlin 1926).

2. A. Götz. Physik und Technik des Hochvakuums, pp. 260, Vieweg, Braunschweig, 1926. R. M. 10.

3. L. Dunoyer. La Technique du Vide, pp. 225, Edit. Journ. de Physique, Paris, 1924. Frs. 15. (English translation: L. Dunoyer. Vacuum Practice).

4. F. Newman. The Production and Measurement of Low Pressures, pp. 192, Edit. Ernest Benn, London, 1925. Sh. 14.

5. W. Germershausen. Die moderne Hochvacuumstechnik, pp. 48, Hochmeister und Thal, Leipzig, 1926.

6. G. Kaye. High Vacua, pp. XII + 175, Longmans Green & C⁰, London, 1927. Sh. 10/6.

The books listed appeared during the last five years. Such a sudden appearance of a large number of books devoted to the treatment of one and the same question is not accidental and is undoubtedly explained by the interest on the part of a broad circle of readers, chiefly technicians and researchers in the field of high vacuum. The reason for this interest is easy to understand. The two fundamental problems now confronting physicists—the structure of matter and the nature of radiation—owe their development to a great extent to the development of means for obtaining a vacuum. The discovery and study of X-rays, electrons, positive rays, and isotopes followed as a result of the study of phenomena in vacuum tubes. The investigation of the large region of the spectrum between ultraviolet and X-rays became possible only thanks to the use of the vacuum spectrograph. The need for means of obtaining and measuring vacuum has become so great that at the present time it is difficult to find a physical laboratory that could do without them. Ready-made vacuum apparatus is also extremely widespread: amplifier and generator tubes, cathode oscillographs, rectifiers, photoelectric cells, all kinds of mercury lamps, glow-discharge lamps, vacuum-

thermoelements, vacuum furnaces, Dewar vessels, etc.—all this is not only widely used everywhere, but often also requires a thorough acquaintance with the science of vacuum.

1. If one does not count Getz’s book, which appeared in 1922 and is now considerably out of date, and which we shall therefore leave out of consideration, then Dushman’s book (1922) is, in age, the oldest, but at the same time one of the very best. In large part it is a systematic exposition of a great number of Langmuir’s works with collaborators, published in American journals during 1913–1921. Along with a brief exposition of the foundations of the kinetic theory of gases, the book gives a description of the most important pumps and manometers, and is supplied with a huge number of line references. The very brief presentation of the kinetic theory of gases is rather a merit of the book than a shortcoming, for on kinetic theory there exists in any case a whole series of special manuals. This conciseness of the first part allowed the author to devote sufficient space to describing the most important pumps and manometers and almost half the book to reserve for the description of the so-called sorption phenomena. With the aid of modern pumps one can theoretically attain an arbitrarily high vacuum. Practical difficulties arise as a consequence of the constant spoilage of the vacuum by gases given off from solid walls. Therefore the chapters on sorption phenomena should be regarded as a great plus in the book. Approximately the same value should be assigned to the chapter on physicochemical methods of obtaining high vacuum, which now, together with methods for degassing glass and metals, play a primary role in all vacuum technique. It must be said that in this second half of the book the discussion is chiefly of works in which the author himself also took part, and therefore, naturally, in places one notices in the book a lack of critical attitude toward certain assertions. It is to be regretted that too much attention is devoted to expounding the theory of the monomolecular layer, which in far from many questions of vacuum justifies the hopes placed upon it. It would have been better to devote more attention to the technique of pumping itself or to the description of factory “getters.” The book is supplied with convenient tables of formulae and constants from kinetic and electronic theory. It would have been good if, instead of two pages of detailed tables of contents, a small alphabetical index had been included.

Dushman’s book has been translated into German (1926). The translation is in places considerably expanded.

1. In his Vacuum Technique Dunuayé does not set himself the task of giving an exhaustive description of all pumps and manometers, but instead, with greater detail than Dushman, describes only some of them, the most applicable. Special attention is devoted to condensation pumps and to Knudsen’s manometer. Another essential difference between these two books is that Dunuayé speaks only in passing about gases in metals, the action of charcoal, and chemical reactions.

in a lamp. This must be regarded as a major shortcoming of the book, though one that is partly excusable if one takes into account the small size and low price of the book. In return, the book contains a whole series of extremely useful data on vacuum technique, which is in fact the principal subject of the book. The methods of microanalysis of gases are described in sufficient detail, which is especially valuable because these methods were published during the war years (1916–1919), owing to which the original literature is not entirely accessible, especially to Russian readers. In other books this question is still not covered at all. The author devotes more attention than Deshman to Campbell’s very important work on the disappearance of gases during an electrical discharge. Finally, the author gives a whole series of very valuable practical pieces of advice: on the calculation of tubing, on the arrangement of all vacuum apparatus, on the use of waxes and mastics, etc. All this distinguishes this book from Deshman’s. Otherwise, the book is written also in its theoretical part. The book does not contain a systematic exposition of the kinetic theory of gases, but in some places, where this is directly required for an understanding of one or another point, theory is also given. All theoretical explanations are made with sufficient completeness, rigor, and, in places, even elegance. Among the shortcomings one should also point out the somewhat lengthy exposition of Langmuir’s work on the adsorption of gases by glass, mica, and platinum, and the derivation of the isotherm equation. For in this work the discussion concerns gases which in vacuum technique play a quite insignificant role. On the other hand, almost nothing is said about water vapor, which in most cases is a real bugbear for those working with vacuum. Duniway sometimes devotes too much attention to describing the most precise work with certain manometers (for example, MacLeod’s and Knudsen’s), but at the same time says very little about glass, which is the chief cause of such deterioration of the vacuum in which overly precise work with manometers is wholly superfluous.

The book was translated into English (1927).

1. Newman’s book, which appeared in 1925, could to a considerable extent no longer be new in comparison with the books published earlier. It represents something intermediate between “Deshman” and “Duniway.” In the character of its exposition it resembles a small encyclopedia. Instead of describing in detail pumps and manometers already described in other books, the author confines himself to short summaries. He devotes special attention only to condensation-type pumps, which he considers the pumps of the future, and, moreover, supplements these chapters with several new descriptions—for example, a description of Coolidge’s manometer with a double quartz fiber and of several pumps of various types, which, however, are not of great importance. The book contains almost no theory—the practical side of the matter is in the foreground. In this respect, however, it differs from Duniway’s book. Newman gives a whole series of interesting practical directions, chiefly

in this way with respect to those questions which are not touched upon at all by Dunoyer and Deshman. The problem of gases and vapors occluded by glass and metals is the most difficult one in the science of vacuum. Newman therefore devotes considerable space to the description of such phenomena as the absorption of gases by various metals, by carbon, and by glass. This large chapter differs somewhat in content from the corresponding passages in Deshman’s book and may be regarded as very successfully compiled, if one excludes the excessively large number of tiresome and unimportant tables (various kinds of carbon and various gases). The description of chemical, thermal, and electrical processes (clean up), as well as of gases in glass, contains little that is new in comparison with Deshman. At the end of the book there is an alphabetical index and a number of very useful tables: elasticities of various vapors, as well as comparative tables for the most commonly used pumps and manometers with brief characteristics of them. The book is written in a very compressed but clear language, contains much good and varied material, and must in general be considered successful, if one does not demand from it detailed information on particular questions.

1. “Physics and Technique of High Vacuum” by Goetz, published in a second, supplemented edition in 1926, differs from the first three by greater systematicity in the description of the most important physical phenomena. The author does not content himself with simple references to the literature, and in places, with considerable detail, gives certain derivations of formulas of kinetic theory, for example Maxwell’s law of the distribution of velocities, Goetz’s formulas concerning the diffusion of gases, etc. The description of the most important pumps and manometers is usually preceded by a sufficiently complete theory. In this way the author almost completely relieves readers of the need to consult the original works. Another difference of this book from the first books consists in a somewhat different selection of material for the chapters on pumps and manometers. Instead of the secondary pumps described in the other books, there is included here a description of a number of the most important modifications of condensation pumps, a description of the water-jet pump—forgotten by other authors—and others. A detailed table indicating the features of many pumps (applicability, operating conditions, limiting vacuum, pumping speed, etc.) is an excellent addition to the chapter on pumps. Approximately the same may be said of the criteria of vacuum. Little space is allotted to the description of secondary manometers, which were discussed in the other books. Instead, the spiral and membrane mechanical manometers, the vacuum thermoelement—also, however, secondary ones—and the luminous discharge are described. Ionization methods are described in much greater detail and better than in the other books. In the chapter on manometers there is also a convenient comparative table. The chapter on evacuation by sorption agents is for the most part borrowed from Deshman’s book. On the action of carbon and metals, as well as on “getters,” unfortunately little is written, but in compensation Goetz has supplemented this part

BIBLIOGRAPHY

the book with a description of drying agents (\(P_2O_5\), etc.), to which the other authors for some reason paid no attention. Quite appropriately, there is a table characterizing various sorption agents with respect to different gases. The book contains a whole series of data on vacuum technique (purification of gases, assembly of apparatus, etc.); in places all this is described with great and interesting detail, but—one must regret this—the evacuation process itself, as in the other books, is described with insufficient completeness. The book has an extensive bibliography, two alphabetical indexes (of names and subjects), and several useful tables illustrating the kinetic theory. In comparison with the other books, Goetz’s book is published much better. Errors occur here and there, though for the most part they are insignificant.

1. In the small book by Gemershausen (1926) there is nothing new. It contains a brief description of the most important pumps, manometers, the glow discharge, and some directions concerning the assembly of apparatus.

2. Almost every one of the authors of the books named above tried to give a sufficiently complete manual on vacuum. None of them succeeded fully. This is understandable, for the science of vacuum has now expanded to such an extent that it is impossible to fit all the most important information on vacuum into 15–18 printer’s sheets. This explains why, after the appearance of a whole series of essentially very good manuals in 1927, Kay issued a new book. Is there anything new in it? Of course, it too appears interesting, but far from for as large a circle of readers as the other books were intended. Kay is a radiologist, and with his little book he comes chiefly to the aid of X-ray technicians, who in other places will find little material directly of interest to them. But for those working in other fields the book will provide less that is new. In order that the booklet should represent something complete, the author, like the others, also discusses a whole series of pumps and manometers, without, of course, going into great detail. To give the book in this respect too a touch of originality, he introduces descriptions of pumps previously left without attention—for example, the water-jet pump, the old rotary pump of Kaufmann, Holweck’s molecular pump, and some new modifications of condensation pumps. But all this is secondary. Very important (though, again, for a narrow circle of readers) is the description of the new powerful condensation pumps of Parsons and others. Also curious is the description of attempts to replace mercury pumps with cadmium ones, although perhaps this is a matter of the distant future. The excessively brief information on physico-chemical phenomena in vacuum is a great minus for the book. What is written about the use of charcoal is quite insufficient even for X-ray technicians, not to mention certain other categories of readers. Of the manometers described in other books, of course, very little is written. On the other hand, other manometers are described more or less in detail. Instead of a description

BIBLIOGRAPHY

for a new manometer with damping (King), it would have been possible to confine oneself to a brief notice and an appropriate reference to the original paper. The important thermocouple manometers of Campbell (G. E. C.) are described quite fully. The book contains no theory, apart from calculations concerning the determination of the speed of action of pumps; these, however, could have been considerably shortened without detriment to the book. In some questions of vacuum technique the book is partly similar to Dunoyer’s book. But the book also contains a whole series of very valuable pieces of information that are not found in other manuals. These include, for example, an extensive chapter on joints between various glasses, with quartz and with metals; further, one should note the description of devices for admitting vacuum (needle valve). In this respect the book differs greatly from previously published books. Another of its features is its extremely lively and popular language. The historical introduction is written very interestingly. One must also acknowledge as quite appropriate the detailed description of discharge in vacuum tubes and of the phenomena occurring thereby. The book may prove to be an excellent supplement to some other book, for example to Gett’s book.

Summarizing this review, let us note the following as well: vacuum technique, having developed chiefly in factories, has gone far ahead of theory. In the art of obtaining high vacuum, scientific laboratories for the most part cannot compare with any of the vacuum factories. There is no doubt that the authors, most of whom work in factory laboratories, know considerably more about vacuum than they write. Nevertheless, in their books we do not find sufficiently complete information, sometimes on extremely important matters, as is clear from the foregoing. Instead, some books are at times replete with entirely superfluous details in the description of one or another secondary subject. The theory of vacuum, likewise, is not presented with sufficient completeness in any of the books; this, however, is to a certain extent compensated by numerous references to the literature (Dushman, Gett, Dunoyer) and is justified by the insufficient size of the books.

N. Shishakov.