作者：Pickering, Edward Charles
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The Future of Astronomy试读：
THE FUTURE OF ASTRONOMY
BY PROFESSOR EDWARD C．PICKERINGHARVARD COLLEGE OBSERVATORY
It is claimed by astronomers that their science is not only the oldest, but that it is the most highly developed of the sciences．Indeed it should be so, since no other science has ever received such support from royalty, from the state and from the private individual．However this may be, there is no doubt that in recent years astronomers have had granted to them greater opportunities for carrying on large pieces of work than have been entrusted to men in any other department of pure science．One might expect that the practical results of a science like physics would appeal to the man who has made a vast fortune through some of its applications．The telephone, the electric transmission of power, wireless telegraphy and the submarine cable are instances of immense financial returns derived from the most abstruse principles of physics．Yet there are scarcely any physical laboratories devoted to research, or endowed with independent funds for this object, except those supported by the government．The endowment of astronomical observatories devoted to research, and not including that given for teaching, is estimated to amount to half a million dollars annually．Several of the larger observatories have an annual income of fifty thousand dollars.
I once asked the wisest man I know, what was the reason for this difference．He said that it was probably because astronomy appealed to the imagination．A practical man, who has spent all his life in his counting room or mill, is sometimes deeply impressed with the vast distances and grandeur of the problems of astronomy, and the very remoteness and difficulty of studying the stars attract him.
My object in calling your attention to this matter is the hope that what I have to say of the organization of astronomy may prove of use to those interested in other branches of science, and that it may lead to placing them on the footing they should hold．My arguments apply with almost equal force to physics, to chemistry, and in fact to almost every branch of physical or natural science, in which knowledge may be advanced by observation or experiment.
The practical value of astronomy in the past is easily established．Without it, international commerce on a large scale would have been impossible．Without the aid of astronomy, accurate boundaries of large tracts of land could not have been defined and standard time would have been impossible．The work of the early astronomers was eminently practical, and appealed at once to every one．This work has now been finished．We can compute the positions of the stars for years, almost for centuries, with all the accuracy needed for navigation, for determining time or for approximate boundaries of countries．The investigations now in progress at the greatest observatories have little, if any, value in dollars and cents．They appeal, however, to the far higher sense, the desire of the intellectual human being to determine the laws of nature, the construction of the material universe, and the properties of the heavenly bodies of which those known to exist far outnumber those that can be seen.
Three great advances have been made in astronomy．First, the invention of the telescope, with which we commonly associate the name of Galileo, from the wonderful results he obtained with it．At that time there was practically no science in America, and for more than two centuries we failed to add materially to this invention．Half a century ago the genius of the members of one family, Alvan Clark and his two sons, placed America in the front rank not only in the construction, but in the possession, of the largest and most perfect telescopes ever made．It is not easy to secure the world's record in any subject．The Clarks constructed successively, the 18-inch lens for Chicago, the 26-inch for Washington, the 30-inch for Pulkowa, the 36-inch for Lick and the 40-inch for Yerkes．Each in turn was the largest yet made, and each time the Clarks were called upon to surpass the world's record, which they themselves had already established．Have we at length reached the limit in size? If we include reflectors, no, since we have mirrors of 60 inches aperture at Mt．Wilson and Cambridge, and a still larger one of 100 inches has been undertaken．It is more than doubtful, however, whether a further increase in size is a great advantage．Much more depends on other conditions, especially those of climate, the kind of work to be done and, more than all, the man behind the gun．The case is not unlike that of a battleship．Would a ship a thousand feet long always sink one of five hundred feet? It seems as if we had nearly reached the limit of size of telescopes, and as if we must hope for the next improvement in some other direction.
The second great advance in astronomy originated in America, and was in an entirely different direction, the application of photography to the study of the stars．The first photographic image of a star was obtained in 1850, by George P．Bond, with the assistance of Mr．J.A．Whipple, at the Harvard College Observatory．A daguerreotype plate was placed at the focus of the 15-inch equatorial, at that time one of the two largest refracting telescopes in the world．An image of α Lyræ was thus obtained, and for this Mr．Bond received a gold medal at the first international exhibition, that at the Crystal Palace, in London, in 1851．In 1857, Mr．Bond, then Professor Bond, director of the Harvard Observatory, again took up the matter with collodion wet plates, and in three masterly papers showed the advantages of photography in many ways．The lack of sensitiveness of the wet plate was perhaps the only reason why its use progressed but slowly．Quarter of a century later, with the introduction of the dry plate and the gelatine film, a new start was made．These photographic plates were very sensitive, were easily handled, and indefinitely long exposures could be made with them．As a result, photography has superseded visual observations, in many departments of astronomy, and is now carrying them far beyond the limits that would have been deemed possible a few years ago.
The third great advance in astronomy is in photographing the spectra of the stars．The first photograph showing the lines in a stellar spectrum was obtained by Dr．Henry Draper, of New York, in 1872．Sir William Huggins in 1863 had obtained an image of the spectrum of Sirius, on a photographic plate, but no lines were visible in it．In 1876 he again took up the subject, and, by an early publication, preceded Dr．Draper．When we consider the attention the photography of stellar spectra is receiving at the present time, in nearly all the great observatories in the world, it may well be regarded as the third great advance in astronomy.
What will be the fourth advance, and how will it be brought about? To answer this question we must consider the various ways in which astronomy, and for that matter any other science, may be advanced.
First, by educating astronomers．There are many observatories where excellent instruction in astronomy is given, either to the general student or to one who wishes to make it his profession．At almost any active observatory a student would be received as a volunteer assistant．Unfortunately, few young men can afford to accept an unpaid position, and the establishment of a number of fellowships each offering a small salary sufficient to support the student would enable him to acquire the necessary knowledge to fill a permanent position．The number of these scholarships should not be large, lest more students should undertake the work than would be required to fill the permanent paying positions in astronomy, as they become vacant.
In Europe, a favorite method of aiding science is to offer a prize for the best memoir on a specified subject．On theoretical grounds this is extremely objectionable．Since the papers presented are anonymous and confidential, no one but the judges know how great is the effort wasted in duplication．The larger the prize, the greater the injury to science, since the greater will be the energy diverted from untried fields．It would be much wiser to invite applications, select the man most likely to produce a useful memoir, and award the prize to him if he achieved success.
The award of a medal, if of great intrinsic value, would be an unwise expenditure．The Victoria Cross is an example of a successful foundation, highly prized, but of small intrinsic value．If made of gold, it would carry no greater honor, and would be more liable to be stolen, melted down or pawned.
Honorary membership in a famous society, or honorary degrees, have great value if wisely awarded．Both are highly prized, form an excellent stimulus to continued work, and as they are both priceless, and without price, they in no way diminish the capacity for work．I recently had occasion to compare the progress in various sciences of different countries, and found that the number of persons elected as foreign associates of the seven great national societies of the world was an excellent test．Eighty-seven persons were members of two or more of these societies．Only six are residents of the United States, while an equal number come from Saxony, which has only a twentieth of the population．Of the six residents here, only three were born in the United States．Not a single mathematician, or doctor, from this country appears on the list．Only in astronomy are we well represented．Out of a total of ten astronomers, four come from England, and three from the United States．Comparing the results for the last one hundred and fifty years, we find an extraordinary growth for the German races, an equally surprising diminution for the French and other Latin races, while the proportion of Englishmen has remained unchanged.
A popular method of expending money, both by countries and by individuals, is in sending expeditions to observe solar eclipses．These appeal both to donors and recipients．The former believe that they are making a great contribution to science, while the latter enjoy a long voyage to a distant country, and in case of clouds they are not expected to make any scientific return．If the sky is clear at the time of
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