Biography of Percival Lowell

by A. Lawrence Lowell

“Where illumination alone is concerned the camera reigns supreme; not so when it comes to a question of definition. Then by its speed and agility the eye steps into its place, for the atmosphere is not the void it could be wished, through which the light-waves shoot at will. Pulsing athwart it are air-waves of condensation and rarefaction that now obstruct, now further, the passage of the ray. By the nimbleness of its action the eye cunningly contrives to catch the good moments among the poor and carry their message to the brain. The dry plate by its slowness is impotent to follow. To register anything it must take the bad with the better to a complete confusion of detail. For the air-waves throw the image first to one place and then to another, to a blotting of both.”

There lay the difficulty which Mr. Lampland, then new to the Observatory, took up in 1903. The photographs, though better, still did not show the canals. Various adjustments were then made with the telescope; all manner of plates were tried between the rapid and the well-defining ones; and finally in 1905 upon the plates canals appeared, thirty-eight in all and one of them double.[16] On learning of the success Schiaparelli wrote in wonder to Percival, “I should never have believed it possible”; and the British Royal Photographic Society awarded its medal to Mr. Lampland.

With the observations of 1905 ended until the next opposition of the planet an exploration and a romance of which he wrote:

“To some people it may seem that the very strangeness of Martian life precludes for it an appeal to human interest. To me this is but a near-sighted view. The less the life there proves a counterpart of our earthly state of things, the more it fires fancy and piques inquiry as to what it be. We all have felt this impulse in our childhood as our ancestors did before us, when they conjured goblins and spirits from the vasty void, and if our energy continue we never cease to feel its force through life. We but exchange, as our years increase, the romance of fiction for the more thrilling romance of fact. As we grow older we demand reality, but so this requisite be fulfilled the stranger the realization the better we are pleased. Perhaps it is the more vivid imagination of youth that enables us all then to dispense with the hall-mark of actuality upon our cherished visions; perhaps a deeper sense of our own oneness with nature as we get on makes us insist upon getting the real thing. Whatever the reason be, certain it is that with the years a narration, no matter how enthralling, takes added hold of us for being true. But though we crave this solid foothold for our conceptions, we yield on that account no jot or tittle of our interest for the unexpected.”

CHAPTER XIV
THE SOLAR SYSTEM

In the intervals of personal observation Percival was often giving lectures or writing on astronomical subjects for the publications of the Observatory, and for scientific societies and periodicals. The substance of most of these found their way into his books, which are summations or expositions of his conclusions. In December 1902, for example, he gave six lectures on “The Solar System” at the Massachusetts Institute of Technology, of which he was a non-resident professor, and they were published by Houghton, Mifflin & Company. Then in the autumn of 1906 he gave a course of eight lectures at the Lowell Institute in Boston on “Mars as the Abode of Life.” These were so crowded that they had to be repeated, were then printed as six papers in the Century Magazine, and finally re-published by The Macmillan Company under the same title. Two years later, in the winter of 1909, he gave at the Massachusetts Institute of Technology, another course of six lectures on “Cosmic Physics: The Evolution of Worlds,” which were brought out in December by the same publisher with the latter half of the title. Although their names are so diverse, and far more is told of Mars in the book whose title contains its name, they all deal essentially with the same subject, the evolution of the planets and the development and end of life upon them. In the Preface to “Mars as the Abode of Life,”—for a preface, although printed at the beginning, is always written after the book is finished, and is the author’s last word to the reader, giving his latest thought as the work is being launched,—he tells us:[17] “Though dealing specifically with Mars, the theme of the lectures was that of planetary evolution in general, and this book is thus a presentation of something which Professor Lowell has long had in mind and of which his studies of Mars form but a part, the research into the genesis and development of what we call a world; not the mere aggregating of matter, but what that aggregation inevitably brings forth. The subject which links the Nebular Hypothesis to the Darwinian Theory, bridging the evolutionary gap between the two, he has called planetology, thus designating the history of the planet’s individual career. It is in this light that Mars is here regarded: how it came to be what it is and how it came to differ from the Earth in the process.”

At each opposition, in fact at every opposition during Percival’s life and long thereafter, Mars was observed at Flagstaff and more detail was discovered confirming what had been found before. He tells of a slight change in the estimated tilt in its axis; the fact that the temperature is warmer than was earlier supposed;[18] and he had found how to discover the gases by spectroscopic analysis applied according to an ingenious device of his own known as “Velocity Shift” and much used thereafter.[19] He tells also of an ingenious and elaborate experiment with wires, and with lines on a wooden disk, which showed that such lines can be perceived at a greater distance and therefore of smaller size than had been supposed, so that the canals might have less width than had been assumed. It is, however, needless, in describing his planetary theory, to do more than allude to his evidence of Martian habitation drawn from the canals, with which the reader is already familiar. Curiously enough, however, it is interesting to note that on September 9, 1909, about the time when “The Evolution of Worlds” was going to press, a strange phenomenon appeared in Mars. Two striking canals were seen where none had ever been seen before, and the most conspicuous on that part of the disk. Moreover, they were photographed. After examining all the maps of canals made at Flagstaff and elsewhere, Percival discussed them in the Observatory Bulletin No. 45, and concluded that they must not only be new to us, but new to Mars since its previous corresponding season of two of our years before: “something extra ordinem naturae.” We may here leave Mars for the time, and turn to the more extensive study of the evolution of the planetary system.

The desire to rise from a particular case to a more general law was characteristic of his attitude of mind, constructive and insatiable, and appears throughout these volumes. It may have been influenced by his great master Benjamin Peirce, who ever treated any mathematical formula as a special instance of a more comprehensive one. In such a subject as the evolution of the planets, especially of life on them, it involved dipping into many sciences, beyond the physical laws of matter; and he says in the same preface: “As in all theses, the cogency of the conclusion hangs upon the validity of each step in the argument. It is vital that each of these should be based on all that we know of natural laws and the general principles underlying them.” This did not mean that all his premises would be universally accepted, but that he found out all he could about them, convincing himself of their accuracy and of the validity of the conclusions he draws therefrom. That is all any man of science can do in a subject larger than his own special, and therefore limited, field.

But from the time of his resumption of research and the direction of the observatory in 1901, he was constantly enlarging his own field by the study of astrophysical subjects, and the methods for their determination. With this object he was initiating and encouraging planetary photography. He was constantly writing Dr. V. M. Slipher about procuring and using spectrographic apparatus and about the results obtained by him therefrom. By this process the rotations of planets were determined; and the spectra of the major ones—often reproduced in astronomical works—have been a puzzle to astrophysicists until their interpretation in very recent years. He was interested also in nebulae, especially in spiral ones, taking part in Dr. Slipher’s pioneering spectrographic work at the observatory, which showed that they were vast aggregations of stars of different spectral types, moving with great speed, and far beyond the limits of our universe. For over fifteen years the observatory was almost alone in this field of research, as well as in that of globular clusters. It is in fact, the discovery of the rapid motion of the spiral nebulae away from the solar system that has given rise to the conception of an expanding universe.

But these discoveries were still largely in the future, and to return to his books on the planetary system it may be noted that in the two larger and more popular ones the general planetary theory is expounded in the text, while the demonstrations of the more complex statements made, and the mathematical calculations involved, are relegated to a mass of notes at the end of the volume.