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EDWARD CHARLES PICKERING By the death of Edward C. Pickering American science has lost one of its most distinguished figures, one of the most noteworthy contributors to its progress during the past forty years, and one of its most inspiring and influential leaders. A full account of his long and active career would demand far more space for its presentation and time for its preparation than are at the moment available; only the main events and achievements of an exceptionally productive life can be touched upon in these few words of appreciation.

Born at Boston, in 1846, of an old New England family, and a graduate of Harvard of the class of 1865, after two years as instructor in mathematics, he became professor of physics at the Massachusetts Institute of Technology, where he established the first laboratory in America in which students were instructed by actual contact with physical instruments and measurements. Upon the death of Professor Winlock, the youngest physicist was called, in 1877, at the age of thirty-one, to the directorship of the Harvard College Observatory, which he held for nearly forty-two years, continuing the tradition of the institution, all of whose directors have died in office.

At this time most observatories were devoting themselves mainly to the old "astronomy of position”—the determination of the apparent positions of the stars and other heavenly bodies upon the celestial sphere, and of those constants of nature which can be derived from such observations and the "new astronomy” (now bet

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ter known as astrophysics) was in its in- with a view to increasing the accuracy of fancy. It is characteristic of Pickering observation, and, above all, to obtaining that he realized at once in what direction rapidity without sacrificing accuracy. In the greatest opportunities lay, and set to the latter particular he was indeed a master. work to employ the full resources of the He possessed a genius for organization observatory in fundamentally important which would undoubtedly have brought him work. Harvard had always been sympa- both wealth and fame in the world of busithetically inclined towards the newer de- ness: but he preferred to devote these talvelopments of astronomical science, and ents to the service of science, and, because considerable photometric work had been of them, enjoyed work of a sort which most done under Bond and Winlock; but, when other men would have regarded as drudgthe new director began to devote the main ery. He once said to the writer, I like portion of his own time, and that of the to undertake large pieces of routine work." fifteen-inch telescope (then one of the great- In the great masses of such work done est in the country) to photometric re- under his direction, the principles of searches, considerable criticism was aroused. "scientific management' were fully ap“Why," said these critics, “should obser- plied. All that could be done by assistants vations with the meridian circle and of moderate capacity was left to them, and micrometer, which yield results accurate al- the whole working time of the experienced most to one part in a million, be neglected specialists was devoted to such parts of the in favor of measures in which differences work as they alone could do. To extend the of five, or even ten per cent. habitually study to the stars of the southern hemisoccur? Can such inaccurate observations phere, a station was established at Arebe of any value in an exact science?quipa, Peru, in 1890, and has been actively

Undaunted by these cavils, he continued maintained ever since, and another has in his chosen course—with what abundant more recently been set up in the island of reason the nearly eighty volumes of the Jamaica. "Harvard Annals" which appeared during The results of these carefully reasoned his directorate may testify. The “old as- plans have been so extensive that only the tronomy" was not neglected-in fact, principal features can be mentioned here, twenty years' time was spent by several leaving a host of minor but highly interestmembers of the staff in preparing each of ing investigations undescribed. the two Harvard zones of the Astronomische In visual photometry, Pickering started Gesellschaft's scheme of international co- almost de novo, devising new measuring inoperation in star-cataloguing-but the as- struments, with which observations of all trophysical work accomplished under Pick- the accuracy necessary for his purpose ering's directorship, and bearing the marks could be made with great rapidity-notably of his genius, is of incomparably greater the meridian photometers, with which the volume and importance. He was a pioneer brightness of stars is measured, as they in several fields, in each of which he has had cross the meridian, by comparison with many followers.

some circumpolar star which is always availHe was never contented with the un

able as

a standard. With these instruthinking adoption of the methods and in- ments more than 45,000 stars have been obstruments of investigation which he found served at Cambridge and Arequipa, and in use, but was always designing new ones, the resulting system of visual stellar magnitudes has been generally adopted as an in- The third principal field of work is in ternational standard. When to these ob- stellar spectroscopy. Pickering led again servations, most of which were made by in the photography of stellar spectra with Professor Pickering himself, are added his the objective prism, and in the more precise numerous measures upon variable stars, classification of stellar spectra which this satellites and other objects, the whole num- made possible. Assisted financially by the ber of photometric settings which he per- liberal aid of the Henry Draper Memorial, sonally made rises to the amazing total of he and his very distinguished assistants, more than a million and a half.

Mrs. Fleming and Miss Cannon, studied He was also a pioneer in stellar photog- these spectra, devised the empirical classiraphy, and especially in the use of the doub- fication of the original Draper Catalogue, let lenses which combine great light grasp and improved upon this by omitting some with a wide angle of field, and can with an of the original classes and rearranging exposure of an hour or two, record on a others, until the resulting classification single plate the positions and magnitudes of proved so convenient, and so remarkably a number of stars which may run into the representative of the actual facts, that it hundreds of thousands. The Harvard was adopted without a dissenting voice by equipment includes instruments of this the International Union for Solar Research type ranging from the 24-inch Bruce tele- as a universal standard. The fact, which scope at Arequipa and the 16-inch Metcalf

was first brought out by this investigation, instrument at Cambridge to the little lenses and served as the basis of the final classifiof one inch aperture which are used to cation, that the spectra of almost all the photograph as large a portion of the visible stars fall into a single sequence, along heavens as possible on every clear night. which each type grades almost impercepThe plates are developed, indexed, and filed tibly into the next, is now recognized as the in the great “Harvard Photographic Li- very foundation of modern astrophysics, brary,” which its creator described as “a and the progress of discovery serves steadlibrary of 250,000 volumes, every one ily to emphasize the importance of classifiunique, and with but a handful of readers cation according to spectral type in the to work in it." The very magnitude of the most diverse problems of sidereal astronmass of information stored in this vast col- omy. In this field, too, the Harvard work lection makes it impossible to extract it all; is of imposing extent, culminating in the but whenever an object of unusual interest “New Draper Catalogue” containing the is discovered, it is only necessary to refer spectra of about 215,000 stars, classified by to the Harvard plates to find out just where Miss Cannon. Professor Pickering took and how bright it was on some three or the liveliest interest in this monumental four hundred dates during the last thirty work, and in the admirably arranged plans years. Among the most notable examples for its production; and it is cause for of this may be mentioned the recognition of gratification that the first volume saw the images of the asteroid Eros upon plates light while he was alive to enjoy it. taken two and four years before its discov- One other series of investigations that ery, and the recent tracing of the history of should not be passed over deals with photothe brilliant new star in Aquila through an graphic photometry. This was one of the interval of thirty years, up to the very day chief interests of his later years, and an inbefore the great outburst.

creasing part of the work of the observatory was devoted to it. The establishment His abiding willingness to use his powerful of a standard system of photographic mag- influence to aid other astronomers in obnitudes proved a difficult and intricate taining instruments for the expansion of problem, but again the results are of pri- their researches, or funds to provide assistmary importance, for the color of a star, ance in the reduction and publication of which is best measured by the difference their observations, is known to all. between its visual and photographic mag- It may be pardonable to speak of one or nitudes, proves to be almost as important as two instances. In conversation, referring its spectral type, to which it is very inti- to the Metcalf Telescope, for which he had mately related. Here again the principal found the funds to purchase the glass disks work of observation was done by others- for the lens, and provide the mounting, Miss Leavitt, Professor Bailey and Pro- while the figuring of the lens was done, as fessor King—but the unifying guidance a labor of love and in his spare time, by the was Pickering's. Closely related to this is distinguished amateur whose name it bears, the discovery of variable stars, which, "I felt as if a great artist had said to me previously largely a matter of chance, was 'If you will buy the canvas, and the brushes reduced to a system, whether by the com- and paint, I will paint you a picture.' parison of plates of the same field taken at If a more personal allusion may be exdifferent times, or by means of certain spec- cused, it may be recorded that, shortly after tral peculiarities. The new methods were the writer's first interview with Professor so successful that the number of variable Pickering (during which he had described stars discovered at Harvard within a few his first serious astronomical work, on years was three times as great as that of stellar parallax) a letter arrived from Harall those detected by all the astronomers of vard, saying in substance “I think that it the world during the previous history of would be useful to determine the magnithe science.

tudes and spectra of all your stars. If you Finally, and by no means least, should will send me a list of them, we will have be recorded his deep interest in, and sup- them observed, and send you the results.'' port of, cooperation between the whole fra- This involved the photometric and spectroternity of astronomers, whether in this scopic observation of some three hundred country or abroad. There was hardly an stars (the photometric settings being made organization for the furtherance of any by Professor Pickering himself) and was specific astronomical aim, such as the Com- offered as an unsolicited contribution to the mittee on the “Carte du Ciel” or the Solar work of a young and unknown instructor! Union, in which he did not take an active The Harvard Observatory never admitted part, and his counsel and advice were al- graduate students of the ordinary sort; and ways of weight. But equally influential, doctoral theses are absent from the long though less conspicuous, was his ever gen- list of its publications. But, under Pickerous aid to individual investigators, to ering, it was an educational center of the whom he was continually transmitting in- first rank, and its pupils were not the imvaluable material from the treasures under mature students, but the working astronhis charge, sometimes observations already omers of the country. Who among us has made, but unpublished, and again data con- not gone to Harvard, enjoyed the delightcerning stars which had been put upon his ful hospitality and finished courtesy of the observing lists for that especial purpose. director, and returned, loaded down with

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data for investigations new or old, and in- scriptive geography, for instance, is geology. spired by his experience with new enthusi- Its value is great and unquestioned, but its asm alike for the magnificent researches of function, like the function of geography, is the great observatory, and for his own

merely to describe and not to explain. humbler work!

Meteorology, on the other hand, is con

cerned with causes, it is the physics of the Such a career deserved unusual recogni- air, a vast subject of rapidly growing imtion, and received it in a merited degree. portance upon which peace and war alike are Almost all the honors of the scientific world becoming more and more dependent. Only fell to his lot, and the list of these distinc- yesterday we tions is too long to detail here. But those

Heard the heavens fill with shouting, and there who knew him will mourn less the disap- rained a ghastly dew pearance of the distinguished leader of sci- From the nations' airy navies grappling in the cen

tral blue; ence than the loss of a warm and loyal

and to-day friend, one of the kindliest and most gen- Saw the heavens fill with commerce, argosies of erous of men.

magic sails, HENRY NORRIS RUSSELL Pilots of the purple twilight, dropping down with PRINCETON UNIVERSITY OBSERVATORY,

costly bales. February 6, 1919

It is, therefore, no longer an opportunity, a

shamefully neglected opportunity, that invites, SOME RECENT CONTRIBUTIONS TO but an imperative duty that commands our THE PHYSICS OF THE AIR1

leading institutions to add to the various subTHERE has come to us from ancient times jects taught, studied and investigated in their the story of a foolish man who sold his birth- departments of physics that eminently valright for a mess of pottage, and that story

uable and fascinatingly difficult branch of to-day is right applicable to us physicists, geophysics—the physics of the air.

No doubt the great majority of colleges and except in one important particular-we haven't

universities would find it highly impracticable even got the pottage. No department of learning has a richer birthright than has the

to add a proper course in meteorology to their

present long list of electives. Neither is it department of physics in meteorology-the

practicable nor desirable for all of them to physics of the air. And yet the few institu

teach anthropology, say, despite its fascinations that even profess to teach this subject

tion, nor even any whatever of the a-to-z kinds in any form offer it through the department of engineering. But it is insisted with all of geology, or, more frequently still, that

possible emphasis that if taught at all it be omnivorous department which, for want of a

taught right-taught as a branch of physics. better name, is called the department of geog

It is also insisted that there is a growing raphy. Statistical meteorology, if such ex

need, especially in connection with both the pression will be permitted, or climatology, is

science and the art of aviation, for young men of course of great interest alike to the geol

who understand the phenomena of the atogist and the geographer and this they should

mosphere. Nor should it be forgotten that teach and in great measure do teach, but when our army called for men trained in climatology is no more meteorology than de- meteorological physics it called in vain—they 1 Address of the vice-president and chairman of

did not exist. Furthermore, it would be a Section B-Physics, American Association for the

godsend to our national Weather Bureau if in Advancement of Science, Baltimore, December,

the future it could secure a larger portion of 1918.

its personnel from among university gradu

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