Beautiful language, true poetry, often contains little truth and not much passion; we feel that the poetry is in the beauty of the images evoked, or in the sheer unanalysable charm of the words as sounds, or—more generally—both combined. The more "thought" there is in poetry the less poetical it is.
There is much virtue in inverted commas, and no doubt "thought" is absent from the Antigone, the Divina Commedia, Hamlet, Paradise Lost, Tintern Abbey, and The Ring and the Book; but we cannot follow Mr. Hill in his contention that these poems lack truth or passion. Nor indeed can we remember any poem of which his remark would be true. Mr. Hill's observations on Emerson's style and his biographical portions of the essay are not quite so off the mark. Few readers will accept his very high estimate of Emerson, and he fails to remove our suspicion that the great American writer, who was never known to laugh, was at times perilously near being an ordinary prig. As to Emerson's influence on his contemporaries and successors, it is generally underestimated. The Essays in particular are always a delight to youth, and are read with avidity by boys at the most impressionable age. A great deal of modern individualism, of modern defiance, which is often put down to the discredit of Ibsen, or Nietzsche, or Blake, is really due to Emerson. He was the first eminent man to preach disobedience as an ethical duty; his conscience was always uneasy if he caught himself conforming; and this uneasiness, which a more vigorous man in a more natural society would have recognised as an emotional mood, Emerson distorted into a kind of council of perfection. "Whoso would be a man must be a nonconformist," he proclaims exaltedly, not seeing that this sentiment has, as a generalisation, already been contradicted by his birth and his marriage, and is to be finally quashed by his death.
SCIENCE
A TREATISE ON GYROSCOPIC AND ROTATIONAL MOTION. By Andrew Gray, F.R.S. Macmillan. 42s. net.
It was quite time that we had in English a standard treatise on gyroscopic motion. Space is, of course, devoted to the subject in various well-known text-books on rigid dynamics, and there are one or two good little books of an elementary nature, such as Perry's Spinning Tops and Crabtree's Spinning Tops and Gyroscopic Motion, but hitherto the man in search of detailed information on problems concerning tops in the widest sense has had to go to Klein and Sommerfeld's Theorie des Kreisels, if he could not find what he wanted in Sir George Greenhill's Report. That Professor Gray should be the man to supply our want is only fitting. At the University of Glasgow, where he succeeded to the chair of Natural Philosophy left vacant by Lord Kelvin's death, an interest in gyroscopic motion is traditional, and Professor Gray inherited a collection of apparatus for experiment in this field which he has extended by many ingenious and convenient forms of gyroscope described in the book before us. His own researches on the general dynamics of gyroscopic systems have added clearness to that branch of applied mathematics, and his son is an expert in the design and application of practical gyrostats. A judicious combination of experimental and theoretical treatment forms the great attraction of Professor Gray's book.
The problems of gyroscopic motion range from the behaviour of the schoolboy's top to that of this great top, the earth, and include a great number of engineering applications. The torpedo is kept in its course by a gyroscope; the gyroscopic compass, which makes no use of magnetic properties, has rendered possible the navigation of a submerged submarine; Schlich invented a gyroscopic apparatus, which has been tried successfully in small ships, for keeping a vessel from rolling in a rough sea; with Brennan's monorail the car is kept upright by means of a gyroscopic device; and many other ingenious uses have been made of the seemingly paradoxical properties of spinning tops. The gyroscopic compass is, unfortunately, not treated in Professor Gray's book, nor is there any account of other naval and military applications of the gyroscope, since the author, finding that the official secrecy, necessarily imposed at the time of writing, would prevent him giving anything but a fragmentary account, has preferred to reserve his discussion of these appliances to a promised second volume. Very little is said of the monorail (in fact, Brennan's name is not mentioned), which is less explicable. Many practical applications of gyroscopic theory to such problems as the drift of projectiles, golf balls, and boomerangs (the last-named treated necessarily in a very general manner) come up for consideration, and the forgotten diabolo, child of a passing craze, is resurrected to provide an example of the effect of equality of the principal moments of inertia on the stability of rotation of a body under no forces. Most attention is, however, given to the first two subjects mentioned above—the top spinning on a flat surface, and the earth spinning through space—which are, of course, the classical problems in rotational dynamics. It need scarcely be said that Sir George Greenhill's work is abundantly cited.
"In the present work my aim has been to refer, as far as possible, each gyrostatic problem directly to first principles, and to derive the solutions by steps which could be interpreted at every stage of the progress," says the author in his preface, and he has followed this aim with considerable success. It is, of course, impossible to treat many of the problems of rotational dynamics without mathematical analysis of some complexity, and a knowledge of elliptic functions and such-like weapons of the applied mathematician lies, perhaps, outside the scope of the average engineer and inventor. Professor Gray, who deplores the present ignorance of inventors in the matter of gyroscopic motion, has kept the needs of this class before him, and has taken care to arrange his matter so that those who cannot always follow the mathematical exposition given can, at least, gain a clear knowledge of the results. The first chapter, which contains no mathematical symbols, forms an excellent introduction to the subject and is quite elementary, and elsewhere in the book, when practical problems, such as the drift of a projectile, are being discussed, the nature of the investigation is stated as simply as may be. Throughout the inquiry is illustrated, as far as possible, by experiment and diagram.
"Les Anglais enseignent la méchanique comme une science expérimentale; sur le continent, on l'expose toujours plus ou moins comme une science déductive et a priori. Ce sont les Anglais qui ont raison, cela va sans dire." In these words, the late Henri Poincaré, the greatest mathematician of his generation, praised the British tradition of teaching dynamics as an experimental subject, which is so well maintained in this book. Some specialists, no doubt, will find minor omissions in their subject, but, on the whole, with the exceptions already noted, the book is very complete. It is printed with the well-known elegance in all that pertains to mathematical symbols of the firm of Robert Maclehose, and the general production is very good. We do not understand, however, why the illustrations in the first chapter are nearly all reproduced a second time further on in the book, especially as they are mostly photographs of apparatus, which do not necessitate frequent reference. And—the question that has to be asked so often with English books—why is the index so defective?
EVERYDAY EFFICIENCY: A PRACTICAL GUIDE TO EFFICIENT LIVING. By Forbes Lindsay. W. Rider & Son. 4s. 6d. net.
It is stated in the preface that the material of this Practical Guide to Efficient Living has been used extensively as a correspondence course, so that anyone who is thinking of paying pounds to be taught by post how to be efficient can save most of his money. All the most notable authorities on Efficiency—Ike Marvel, Buddha, Arnold Bennett, Walter Dill Scott, Prentice Mulford, Yoritomo-Tashi, and Baudelaire (to what the last-named said is added what he might have said)—are quoted, and many varieties of type and a liberal use of capital letters add to the strenuousness of the book. There is much about Ideals ("Ultimate and Other Ideals") and much about Money, much about Character Formation and much about Vocational Efficiency. We attribute our own inefficiency largely to the fact that we cannot whistle, for this seemingly trivial accomplishment is of far-reaching use—"Whistle and wear a smile for fifteen minutes, and you will most assuredly begin to feel cheerful"; "Sing and whistle as you dress." But, again, we have not done the essential thing, which is, we are told, to read the lessons of the Course again and again, and to devote close thought to them. Alas, we fell a victim to Waning Will, a fault early handled in the book, and although somewhat comforted to learn that it is a "common form of weakness," we could not bring ourselves to adopt the cure, which is "When a resolution is formed, record it definitely in your file under the head of Ideals, Aspirations, Tasks, Duties, or other appropriate designation." The appropriate designation for the reading of this book is undoubtedly Task. The author, who has also written books entitled Efficiency and The Psychology of a Sale, is a man who has evidently obeyed his own great precept, "Don't admit any limit to your attainment and capacity." His intense self-respect will prevent him feeling hurt on learning that a smile is the only aid to efficiency which we have derived from his book.