Popular Science Monthly/Volume 9/July 1876/Editor's Table



WE some months ago printed a paper describing briefly the leading features of Mr. Crookes's discovery of the mechanical action of light. We this month publish a more elaborate article under the same title, with new illustrations, in which the distinguished discoverer goes more fully into the subject, states how he was led into the investigation, explains the construction of the instrument, traces out the action of different kinds of rays, shows the value of the contrivance as a photometer or light-measurer, explains its magnetic and electrical relations and how its motions may be recorded, suggests its meteorological uses, and finally considers its results as determining the amount of the force of sunlight upon the earth. Nothing could better illustrate the wide and complex interactions and dependencies of natural phenomena than the circle of questions that is opened by the introduction of this ingenious invention.

The radiometer (so called because of its capacity of measuring radiations) is a very simple instrument (as will be seen by referring to Fig. 8, page 269), consisting of a small glass globe from which the air has been pumped out, and containing four arms supported at the centre by a fine point, and carrying at their extremities thin vanes or disks, white upon one surface and dark upon the other. When light from any source falls upon it the arms begin to revolve, the white surfaces approaching the light and the dark surfaces receding from it as if repelled or pushed away. We have before us a radiometer made by Geissler, the inventor of "Geissler's Tubes," which consists of a globe two and three-quarters inches in diameter, with its downward stem resting on a

wooden base, the whole being ten inches high. It is in motion constantly in the daytime, propelled by the diffused light from the window, and, if the curtain be dropped and the room darkened, the faint light that comes in at the side maintains it in slow revolution. As the intensity of the light increases the motion is quickened, and when the instrument is placed directly in the solar rays the revolutions are so rapid that they cannot be counted. Mr. Crookes made one instrument so delicate that a single candle would drive it at forty revolutions per second.

In the hands of many the radiometer is now only a curiosity and a toy, yet to the physicist it is an instrument of great interest as displaying a new aspect of dynamical phenomena, and may help to explain still further the nature of the radiant forces, and perhaps throw light upon other questions. It is attracting much attention from scientific men, who may be expected in due time to report the results of their own reflections and experiments upon the subject.


The exhibition at Philadelphia has many features of interest, one of the highest of which is that it stands out before the world in a moral and religious aspect as a tribute to the dignity, inspiration, and sacredness of conscientious and successful labor. The warriors, politicians, orators, have their honors elsewhere; the Centennial Exposition is an ovation to the "captains of industry." The multitudinous display is all due to the achievements of labor, to head-toilers and hand-toilers—the devotees and the heroes of science and art. Each product that is gathered ill that great museum has had its history, which in most cases will show a long, laborious, painful struggle after perfection, by faithful study of the laws of Nature, manifested in the operations of forces and the properties of matter. Now, these laws of Nature are the laws of God, or there are no laws of God. The divine will is disclosed in the immutable ordinances of being, and the order of the world, or there is no such disclosure to man. And to seek to know the divine will as expressed in the laws by which things are governed, and to conform action and conduct to them, is the essence of religion, or there is no religion. The denial that this great gathering of the noblest fruits of the world's thought and industry has in it a religious element, and is grounded upon a religious basis, answers to our notion of atheism and heathenism. Can we indeed assert that those who have thrown light into the dark places of Nature that the earth might be subdued, and humanity elevated, and life beautified and enriched, have not been engaged in an eminently religious service? Shall we say that the Eternal Mind, in instituting the laws of material things—chemical, physical, biological—has claims upon our religious reverence, while the human mind in discovering and applying these laws to ends of beneficence is engaged in a non-religious work? If God framed the mysterious order around us and adapted the human mind to unfold itself by studying out these mysteries, can we render him any truer homage than is implied in the consecration of thought to these studies, and in carrying on the constructive and creative works which the resulting knowledge makes possible? No! we heartily agree with Carlyle when he says, "Older than all preached gospels is that ever-enduring evangel, work is worship."

The trophies of productive knowledge and inventive genius are brought together in the vast exhibition, and what are they but witnesses that men have studied faithfully and labored well? The honesty and integrity of human effort are attested in the processes and results. The laws of Nature hold true—there is never a break in the continuities of effect—and heat, light, air, affinities, cohesions, attractions, and all the properties of elements, and the habitudes of energy, never falter for an instant, and all goes on harmoniously and successfully. Who but the irreligious can fail to recognize the solemn implications of these wonderful results; and how otherwise can they be construed by the reverent mind than as God's immediate maintenance and indorsement of the work?

The exhibition has been planned and carried out for one purpose—to be seen and to become a source of instruction and elevation to the beholders. It is designed for all classes to come and examine its treasures, and learn its lessons. The public has been taxed to establish it for purposes of public use, to be attained only by opening its gates to all comers. Its influence is undoubtedly salutary and elevating and to be every way promoted. Attendance is expensive, difficult to many, and impossible to many more. It has been enormously costly that it might be greatly valuable; and its managers are bound to leave nothing undone to carry out its design, which is to be open to the inspection of the largest possible number of people.

Yet, strange to say, the commissioners who control it have decided that it shall be shut up fourteen per cent. of the available time! They have decided to destroy one-seventh of its usefulness. They decree that one day in the week nobody shall see it. Though so extensive that much time is required for even a partial observation of it, the managers determine that the little time visitors have shall be curtailed. And, what is worse, they shut it up the very day of all others when it would be most available to thousands. Though designed to honor labor, it is closed at the only time when multitudes of laborers have an opportunity to attend it.

And what is the reason of so apparently extraordinary and stultifying a course? After so much trouble to get it open, why do the commissioners shut it up this considerable portion of the time? The answer is, it is done in the name of religion! Religious people protest that its opening on Sunday would be a violation of the sacredness of that day, and a violation of the laws that enforce its religious observance. Influential religious bodies have passed resolutions and sent committees to Philadelphia to press this view upon the commissioners. Now, we strongly protest against this assumption that the opening of the exhibition any day of the week will be an irreligious act. The Jew may hold it wicked to visit the show on Saturday, and the Christian may hold it sinful to visit it on Sunday, and both may obey their consciences and stay away on the days they hold sacred; but to force their views upon people who think differently is not a dictate of religion but of persecuting bigotry. A century or two hence, in revising the "History of the Conflict," it will be contemptuously denied that religion was responsible for shutting up the Industrial Exhibition of 1876, against the people, and nullifying its usefulness one day in the week. It will be attributed to superstition, to theological influence and sectarian intolerance. It will be said it is a libel on religion to charge it with the narrowness and prejudice of the times when such a thing could be done.

The position of the Sunday question is simply this: there are two Sundays which we are called upon to recognize in different ways, and on totally distinct grounds, namely, the Sunday of rest from labor for secular reasons, and the puritanical Sunday, devoted to pious observances. The former is enforced by the state, on grounds of public and general utility; the latter is enforced by theological influences for reasons claiming to be religious, and stands upon an ecclesiastical basis. The secular Sunday—the Sunday of rest from labor—is an institution aiming to promote the social welfare, appealing to the sanctions of reason, and is enforced with the discretions of commonsense, and under limits which recognize the admissibility of a certain amount of labor for the general benefit. These are the considerations to which all parties appeal in advocating a day of rest, and they are the sole considerations by which legislators have any right to be moved in legally establishing it. Granting their right to ordain a general suspension of labor one day in the week, for the general good, they have no warrant to go a step beyond this in the direction of restraints upon the free action of individual citizens. They have no more authority to establish a particular religious day than to establish a particular religion. When people desist from work on Sunday, they comply with all that the state can justly require of them, and are left free to occupy themselves in any way they please, subject to the usual regulations of conduct which are in force at all times.

But ecclesiastical influence is constantly striving to turn the secular Sunday to theological account, and to invoke the interference of law with the freedom of citizens in religious matters. The history of the puritanical Sunday has been for centuries the history of meddling with the liberties of conduct, of the coercion of conscience, and the enforcement of observances on alleged religious grounds. The most innocent actions have been held as profanation of the Lord's day. All amusements were forbidden as wicked, and it was held as sinful to kindle the fire, or dress meat, or visit the neighbors, or walk abroad in the fields. Acts intrinsically proper have been construed as crimes if done on Sunday. The absurdities of sabbatarian legislation illustrate the grossest superstitions of the past. The following statement from Cox's "Sabbath Laws" represents the character and logic of the old practices: "At Aberdeen, in the month of November, 1608, a great panic arose by reason of an earthquake which had visited the city, and as the cause of the earthquake was distinctly traceable to the custom of salmon-fishing on Sunday, the proprietors of the salmon-fishings were summoned before the Session and solemnly rebuked." This may seem ridiculous, but do we not still hear of the judgments that follow Sabbath-breaking?

And it is important to note that, when viewed even theologically, the strictness of the Puritan Sunday is without authority. If the Old Testament is appealed to, the fourth commandment forbids work with emphatic detail on the seventh day of the week, but forbids nothing else. If the New Testament is appealed to, we find Christ nowhere establishing Sunday, but entertaining such latitudinarian views on the subject as to incur the reproaches of the pietistic Pharisees for Sabbath-breaking. And in reply to their puritanical notions he curtly told them that "the Sabbath was made for man, and not man for the Sabbath." Hence it has been justly said that "Christ himself did nothing more by word or act than protest against the superstitious abuses which in course of time had grown around the Sabbath." Paul exhorts the Colossians to independence of thought upon the subject, and to let no man judge them in respect of holidays, new moons, and Sabbath-days. It is alleged that there is no evidence that the early Christians kept Sunday, or the first day of the week, with Jewish strictness, but that it was first enforced by law in a. d. 386 by the Emperor Constantine, "who attached just as much importance to his own birthday as to the day of the Lord." But the puritanical spirit grew apace. "In proportion as the Church triumphed over paganism, so did the Christian days over those of the old world. The Church naturally used every effort to secure an increased respect for the days of its own creation. And though it was not till the time of Leo the Philosopher (889-910) that Sunday field-work was forbidden by an imperial law, in reference to public games and amusements the ascetic tendencies of the Church were earlier and more generally felt. The first innovation in this direction was the law of Theodosius the Elder, which included in its prohibition not only secular business but secular amusements. Abstinence, therefore, from toil and pleasure, having thus become the law of the Christian empire, the subsequent history of Sunday resolves itself simply into an extension of the principle."

Coming down to the Reformation, we find its master-spirits still struggling against the tendency to sabbatarian intolerance. "Cranmer speaks of Sunday and other days as mere 'appointments of the magistrates,' but considers that a sufficient reason for their observance." Tyndale says: "As for the Sabbath, we be lords of the Sabbath, and may yet change it into Monday, or into any other day as we see need, or may make every tenth day a holy day, only as we see cause why; neither need we any holy day at all if the people might be taught without." Luther said: "If anywhere any one sets up its observance on a Jewish foundation, then I order you to work on it, to ride on it, to dance on it, to do anything that shall remove the encroachments on Christian liberty." Calvin, in this, was equally liberal, and set an example by playing the game of bowls on Sunday. In all these cases we note the recognition of Sunday as a human institution, subordinate to the uses of man, while the puritanical Sunday, which represses recreations and stifles worldly enjoyments, is resisted and repudiated. The institution in its theological aspects is, therefore, destitute of any authoritative religious sanction. But, after centuries of contest between liberality and intolerance, the issue is still the same. As a day of rest from labor, Sunday is objected to by but few; and to the slave and the convict, and the millions of toil-worn operatives in factory, mine, and field, who earn their subsistence by the sweat of the brow, it is indeed a precious boon. To the multitudes doomed to a life of brutalized drudgery in barbaric times, it came as a blessed relief; and it is, perhaps, scarcely less necessary when the pressures of enterprise and competition would wear men out if no check was interposed. But the sour and gloomy Sunday of religious asceticism—the austere Sabbath of the sanctimonious Pharisee—requires to be resisted now as much as it was resisted by the founder of Christianity himself. In regard to the strict observance of Sunday, men have undoubtedly a right to do as they please under our guarantees of religious liberty; but they have no right to force their views upon others by perverting the legal day of rest to assumed religious objects, and by making it a hinderance to enjoyment and improvement on the part of those who desire so to employ it, and who are not to be judged by others in their manner of doing it.

It is objected to the opening of the exhibition on Sunday that it would involve the labor of many in attending to its operations, running trains, etc. But even the superstitious Jews had sense enough to interpret the fourth commandment as allowing works of necessity. A certain amount of Sunday labor is everywhere recognized as unavoidable, and as long as cooking, the running of Sunday cars and carriages, police surveillance, and the distribution of the mails, are carried on in Philadelphia under Pennsylvania laws, the objection to opening the exhibition because it would violate the law against Sunday labor is futile.

But we insist upon keeping the argument upon its highest grounds. We showed at the outset that the character and influence of such an exhibition are not only in the highest degree moral and salutary, but are also essentially religious; its opening every day of the week is therefore defensible on strictly religious grounds. We have furthermore shown that the religious reasons offered, for shutting it up on Sunday, are baseless. The considerations urged for closing are hence exactly those which require it to be free of access to the public—in other words, religion requires the opening. If it be alleged that the people would not see these higher meanings of the objects displayed, that only shows the defects of their religious training; and that there is all the more need of insisting upon this higher office of the exhibition. And if they are thus insensible to the moral and religious significance of so grand a collection of the noblest and most perfect products of human thought and skill, what more proper than to point out to them the elevated lessons that they teach? And if, instead of demanding that the exhibition shall be suppressed one day in the week, as if it were a public nuisance, the committees who have taken so deep an interest in the matter had asked the commissioners to arrange for religious services in one of the great halls, and to provide for discourses designed to bring out the higher instructiveness of the occasion and the demonstration, we think that they would have much better subserved the interests of true religion. The religious lesson that the commissioners have now lent themselves to inculcate is that people shut out from the Centennial buildings shall go to other buildings to think upon God; and that, therefore, the Centennial collection is a mere godless, sordid, anti-religious affair. But the people do not go to the appointed places of religious assembly. They crowd around the grounds by thousands, and occupy themselves in drinking at the saloons, and in cursing the bigotry of the management which forbids them to look upon the objects within, on the day that the State forbids them to work.

We fear, however, that any considerations of principle will be wasted upon the commissioners. The reasons they avow for forbidding entrance to the grounds on Sunday are not of a very elevated kind. In the report of the majority, after referring to the legislation of the country to prevent "secular business operations" on the "Christian Sabbath," they say: "Any action of this commission which is in conflict with the public sentiment expressed in these laws and in their practical observance will, in the judgment of your committee, so shock the moral sense of the country that it will jeopardize the success of the Centennial Exhibition, and turn the most powerful agencies throughout the land from active support to decided opposition. Your committee, therefore, recommend that the commission adhere to the policy which has heretofore governed its actions on this subject." It is not the "moral sense" of the community that would be shocked by opening the exhibition on Sunday. The "powerful agencies throughout the land" that would oppose it by deterring people from attendance on week-days, because those who wish it were admitted on Sunday, are not impelled by "moral sense," but by a narrow spirit of intolerance which is as immoral as the spirit of any other tyranny. The commissioners are of course bound to do every proper thing to insure the success of the exhibition; but they are not bound to eliminate all higher considerations from their conception of "success." We could wish them a little more elevation of view on this great national occasion; and in regard to their Sunday policy a little more of the spirit of Christ and Paul, Tyndale and Luther; a little more, indeed, of the genuine "spirit of Seventy-six."