of this country, baffles analysis; but to Nelson, above all his contemporaries, honour is due. It is Captain Mahan's great merit to have shown clearly that Nelson was far more than a fighting seaman. The great principle, that the offensive rôle was essential to the British Navy, dominated his actions. In 1795 he writes: 'I have no doubt but that, if we can get close to the enemy, we shall defeat any plan of theirs; but we ought to have our ideas beyond mere defensive measures.' He fully understood that, in certain circumstances, the loss of a squadron would be justified if the enemy's project could thereby be thwarted. When awaiting the incursion of Bruix into the Mediterranean, by which the British fleet was placed in a position of great numerical inferiority, he thus writes to St. Vincent: 'Your lordship may depend that the squadron under my command shall never fall into the hands of the enemy; and, before we are destroyed, I have little doubt but that the enemy will have their wings so clipped that they may be easily overtaken.' No one ever more perfectly grasped the fact that risks must be taken in war; no one certainly was ever more willing to take risks for a sufficient object. Yet Nelson, when determined to fight, left nothing to chance, never neglected details, willingly accepted counsel, while never for a moment evading responsibility, and was particularly careful in imparting his views to his captains. 6 A rare combination of qualities is thus implied. Captain Mahan sums these qualities as follows: For success in war, the indispensable complement of intellectual grasp and insight is a moral power, which enables a man to trust the inner light-to have faith-a power which dominates hesitation and sustains action in the most tremendous emergencies.' These qualities-rare in due combination-met in Nelson, and their coincidence with the exceptional opportunities afforded him constituted his good fortune and his greatness.' One other quality is, however, essential to a great commander-the power of winning the love of his subordinates and so of obtaining their best services. This also Nelson possessed in a marked degree. Restive under incompetent superiors, he was always thoughtful of the welfare of his inferiors. The man who, just before Trafalgar, recalled the mail by signal because a petty officer of the Victory had omitted to post a letter to his wife, and who refused to give to his valued friend the command of a seventy-four because it would rob a lieutenant of coming honour-'No, Blackwood, it is these men's birthright, and they shall have it'-could count upon the loyal support which never failed him in the hour of battle. Captain Mahan has given us incomparably the best life of Nelson that has yet appeared. No other writer could have paid so worthy a tribute to the greatest director of naval war-a tribute which gains in force because of its evident spontaneity. To the British nation the value of this book cannot be overrated. The principles which guided Nelson to victory are eternal; the qualities he displayed have now a far wider scope than in his day. For rapidity and certainty of movement favour the offensive, and, by conferring a vast increase of possibilities, distinctly enhance the importance of the personal factor. Nelson was the most brilliant exponent alike of a national policy and a national spirit. If we cling to the one and keep alive the other, the unknown future can be calmly awaited. G. S. CLARKE. THE NEW ASTRONOMY: A PERSONAL RETROSPECT WHILE progress in all branches of knowledge has been rapid beyond precedent during the past sixty years, in at least two directions this knowledge has been so unexpected and novel in character that two new sciences may be said to have arisen: the new medicine, with which the names of Lister and of Pasteur will remain associated; and the new astronomy, of the birth and early growth of which I have now to speak. The new astronomy, unlike the old astronomy to which we are indebted for skill in the navigation of the seas, the calculation of the tides, and the daily regulation of time, can lay no claim to afford us material help in the routine of daily life. Her sphere lies outside the earth. Is she less fair? Shall we pay her less court because it is to mental culture in its highest form, to our purely intellectual joys that she contributes ? For surely in no part of Nature are the noblest and most profound conceptions of the human spirit more directly called forth than in the study of the heavens and the host thereof. May we not rather greet her in the words of Horace: 'O matre pulchra filia pulchrior'? As it fell to my lot to have some part in the early development of this new science, it has been suggested to me that the present Jubilee year of retrospect would be a suitable occasion to give some account of its history from the standpoint of my own work. Before I begin the narrative of my personal observations, it is desirable that I should give a short statement of the circumstances which led up to the birth of the new science in 1859, and also say a few words of the state of scientific opinion about the matters of which it treats, just before that time. It is not easy for men of the present generation, familiar with the knowledge which the new methods of research of which I am. about to speak have revealed to us, to put themselves back a generation, into the position of the scientific thought which existed on these subjects in the early years of the Queen's reign. At that time any knowledge of the chemical nature and of the physics of the heavenly bodies was regarded as not only impossible of attainment by any methods of direct observation, but as, indeed, lying altogether outside the limitations imposed upon man by his senses, and by the fixity of his position upon the earth. It could never be, it was confidently thought, more than a matter of presumption, whether even the matter of the sun, and much less that of the stars, were of the same nature as that of the earth, and the unceasing energy radiated from it due to such matter at a high temperature. The nebular hypothesis of Laplace at the end of the last century required, indeed, that matter similar to that of the earth should exist throughout the solar system; but then this hypothesis itself needed for its full confirmation the independent and direct observation that the solar matter was terrestrial in its nature. This theoretical probability in the case of the sun vanished almost into thin air when the attempt was made to extend it to the stellar hosts; for it might well be urged that in those immensely distant regions an original difference of the primordial stuff as well as other conditions of condensation were present, giving rise to groups of substances which have but little analogy with those of our earthly chemistry. About the time of the Queen's accession to the throne the French philosopher Comte put very clearly in his Cours de Philosophie Positive the views then held, of the impossibility of direct observations of the chemical nature of the heavenly bodies. He says: On conçoit en effet, que nous puissions conjecturer, avec quelque espoir de succès, sur la formation du système solaire dont nous faisons partie, car il nous présente de nombreux phénomènes parfaitement connus, susceptibles peut-être de porter un témoignage décisif de sa véritable origine immédiate. Mais quelle pourrait être, au contraire, la base rationnelle de nos conjectures sur la formation des soleils eux-mêmes? Comment confirmer ou infirmer à ce sujet, d'apres les phénomènes, aucune hypothèse cosmogonique, lorsqu'il n'existe vraiment en ce genre aucun phénomène exploré, ni même, sans doute, EXPLORABLE? [The capitals are mine.] We could never know for certain, it seemed, whether the matter and the forces with which we are familiar are peculiar to the earth, or are common with it to the midnight sky, All sow'd with glistering stars more thicke than grasse, For how could we extend the methods of the laboratory to bodies at distances so great that even the imagination fails to realise them? The only communication from them which reaches us across the gulf of space is the light which tells us of their existence. Fortunately this light is not so simple in its nature as it seems to be to the unaided eye. In reality it is very complex; like a cable of many strands, it is made up of light rays of many kinds. Let this lightcable pass from air obliquely through a piece of glass, and its separate strand-rays all go astray, each turning its own way, and then go on apart. Make the glass into the shape of a wedge or prism, and the rays are twice widely scattered. First the flaming red Sprung vivid forth: the tawny orange next; Within this unravelled starlight exists a strange cryptography. Some of the rays may be blotted out, others may be enhanced in brilliancy. These differences, countless in variety, form a code of signals, in which is conveyed to us, when once we have made out the cipher in which it is written, information of the chemical nature of the celestial gases by which the different light rays have been blotted out, or by which they have been enhanced. In the hands of the astronomer a prism has now become more potent in revealing the unknown than even was said to be Agrippa's magic glass.' It was the discovery of this code of signals, and of its interpretation, which made possible the rise of the new astronomy. We must glance, but very briefly, at some of the chief steps in the progress of events which slowly led up to this discovery. Newton, in his classical work upon the solar spectrum, failed, through some strange fatality, to discover the narrow gaps wanting in light, which, as dark lines, cross the colours of the spectrum and constitute the code of symbols. His failure is often put down to his using a round hole in place of a narrow slit, through the overlapping of the images of which the dark lines failed to show themselves. Though Newton did use a round hole, he states distinctly in his Optics that later he adopted a narrow opening in the form of a long parallelogram-that is, a true slit-at first one-tenth of an inch in width, then only one-twentieth of an inch, and at last still narrower. These conditions under which Newton worked were such as should have shown him the dark lines upon his screen. Professor Johnson has recently repeated Newton's experiments under strictly similar conditions, with the result that the chief dark lines were well seen. For some reason Newton failed to discover them. A possible cause |