success; and if the same test of efficiency cannot be applied to the other, it must at least be confessed that his task is an exceptionally discouraging one. What would you say, Sunday after Sunday, to five hundred madmen? For the matter of that, what would you say to five hundred sane persons? I have an idea that, if given sufficient time in which to prepare it, I could preach one really admirable sermon, and it would not surprise me to hear that you also entertained a similar modest notion. But what about fifty-two or a hundred and four sermons in the course of the year? And next year?-and the year after? Among all the spinners of emptiness, I think the clergy are those who merit the largest share of leniency and obtain the least. The unfortunate occupant of the pulpit must hold forth once a week, whether he will or no; and it would be as unreasonable to require a perpetual supply of grain without chaff from that hebdomadal mill as to expect a similar boon from the politicians with whose oratory a general election deluged the country not long ago, and who cannot object to hearing their speeches rated at zero, seeing that some of them have since shown so much willingness, not to say eagerness, to admit the impeachment, and to explain that if, in the heat of the struggle, they said so and so, and so and so, they in truth meant nothing at all-nothing, that is, except in a general way, "Codlin is your man, not Short." It is evident that a candidate can't announce himself in that bald, concise sort of way; some flowers of rhetoric must needs be scattered among the throng, where they are usually appraised at precisely their proper value. Every now and then, to be sure, some thick-headed, humourless creature will start up and demand explanations, proofs, authorities, or what not; but we may be pretty sure that by the nation at large the time-honoured joke of an appeal to the electorate is tolerably well understood, and that the number of votes lost to A. by the eloquence of B., or vice versâ, is small indeed.

Yet surely it would be a pity if the eloquence were altogether suppressed. It is mostly innocuous; it is sometimes amusing; at the least it affords subjects for conversation and for the letting loose of the stored-up wisdom of leading articles. By-and-by, when the honourable and right honourable gentlemen are duly elected, comes more eloquence, followed by more leading articles; and what is the upshot of a great part of it? Heaven forbid that the insignificant writer of this disquisition should compare the legislators of his country to that class of animals from whom much cry and little wool is to be expected. Still, it can't be denied that there is a good deal of cry. It would not be difficult to point to certain matters upon which

a stupendous amount of argument and discussion has been expended, and of which the outcome is as invisible as was the Spanish fleet before it came in sight. I do not allude to the measures which engage our attention at the present day; for these are, of course, of the last importance, and are fraught with incalculable consequences to the human race; but looking back into history, one seems to be able to distinguish a host of bitter controversies which have terminated in a general "As you were!"-revolutions succeeded by restorations and reactions-long wars which have ended in nothing, or even in less than nothing; the result presenting itself in the form of a row of figures with a doleful minus-mark for prefix.

And what of the separate atoms who, through their rulers and representatives, have thus spent time and money, and split hairs, and waged wars? Has the harvest proved more satisfactory to them individually than collectively?

Ich setzt mein Sach auf Kampf und Krieg,

Und uns gelang so mancher Sieg;

Wir zogen in Feindes Land hinein,

Dem Freunde sollt's nicht viel besser sein,

Und ich verlor ein Bein.

Here is a minus-mark with a vengeance. Alas! the history of the world is the history of the individual. Who can cast a backward glance upon the resolutions, the projects, the promises of bygone years, without seeing a crowd of zeros dwindling away into the distance, with here and there a minus-mark amongst them? I once heard a prosperous gentleman assert that, if he had his life to live over again, he would not alter it in a single particular; but I imagine that he, if sincere, was very nearly a unique specimen of the race. For most of us the past has little to show but a succession of disappointments and mistakes-" For who knoweth what is good for a man in this life, all the days of his vain life which he spendeth as a shadow?"

But perhaps enough has been said upon a subject which, it will be seen, is susceptible of indefinite development. In ages past and, to all appearance, in ages yet to come, men have laboured and will labour anxiously, indefatigably, at the production of nothing. Pending the advent of the millennium, this state of things must be submitted to, and, indeed, is not without its consolations. For wasted labour is better than no labour at all. It is better to do nothing actively than passively; it may even be better to write an idle essay about nothing than to fall asleep in the daytime.

Two-and-thirty years ago, when they were setting up ateliers

nationaux, to the huge delight of some 100,000 lazy workmen, in Paris, all sorts of grand results were predicted for this singular enterprise. There was to be an end and a finish of the do-nothings. Not only was compulsory idleness to be abolished at once and for ever, but voluntary idleness likewise was to be shamed into disappearance; and, as time went on and ideals realised themselves, a paternal government, having the supreme direction of work, was to help every man in that art or trade for which nature had best fitted him, and thus put an end also to misplaced energy; so that altogether it was a very fine scheme. But that, too, ended in nothing.

W. E. NORRIS.

SCIENCE NOTES.

THE PHOTOPHONE.

CIENCE is usually stern and cool; sober, deliberate, and cal

SCIE

culating but now and then it suddenly breaks loose in wild, sensational outbursts. The photophone is the most recent instance of such impropriety. The idea of talking to a sunbeam, and the sunbeam repeating the conversation to a friend a quarter of a mile distant, is apparently more congenial to Baron Munchausen than to sober physicists.

It is far too startling to have escaped the daily newspapers, and therefore my readers must know more or less about it already. Still, I cannot pass it over altogether, especially as some of the first published accounts of it dashed forth very confidently a rather plausible but totally fallacious explanation of the marvel. They stated that Mr. Bell had succeeded in converting the light-waves into sound-waves. There is no foundation for this. The tremors producing a ray of light are very different from the tremors of the rays of light, or rather of the beam of light, upon which the action of the photophone depends.

Place a tumbler-or, better, a finger-glass-of water on a table in such a position that direct sun-rays shall strike the surface of the water, and from this surface be reflected on the ceiling. A patch of light corresponding to the size and shape of the water surface will there be seen. Now draw a well-rosined violin bow along the edge of the glass so as to produce a sound. Immediately the sound starts the water will be agitated, quite a storm of little waves will appear on its surface. The sunbeam reflected from the surface will be similarly agitated, and the image on the ceiling correspondingly disturbed. If mercury be substituted for water, the experiment will be more demonstrative.

This flickering, waving, or agitation of the sunbeam is quite different from the tremors of the luminiferous ether which are supposed to constitute the light itself. It is the ready-made light that is disturbed, not the light producer.

The above experiment is suggested because it may be easily made, and the effects are coarse enough to be just visible. With suitable apparatus we may prove that a solid surface is agitated similarly to the water surface when acted upon by the waves of sound. This is done by making the well-known experiments of sprinkling sand on glass or metal plates and drawing a violin bow across their edges, or that of similarly covering a stretched membrane and singing to it. In both cases the sand or finer powder arrays itself in beautiful geometrical figures corresponding to the "nodes," ie., the valleys between the wave-hills of the plates or membrane, and thus demonstrates the vibration, and to a certain extent draws its portrait.

If such a solid vibrating surface be made to reflect a beam of light, it is evident that the beam will flicker according to the varying angles which the waves of the undulating mirror surface present to the incident rays, and this flickering beam may be reflected upon another surface, as our beam from the tumbler of water was reflected to the ceiling surface.

This is what is done by Mr. Bell in the construction of his photophone. The voice of the speaker is directed against the back of a flat mirror made of material sufficiently elastic and flexible to be set in decided undulatory movement by the sound-waves of the air. A plate of thin glass or mica, covered on one side with a bright film of chemically deposited silver, is used. A beam of sun-light concentrated by a lens strikes the silvered face, while the voice behind throws the plate into undulatory motion. The light beam is reflected from this, and trembles or flickers in exact correspondence to the move. ments of the reflecting surface. The trembling beam is caught upon the "receiver," a disc of hardened india-rubber stretched like the drum of our own ears at the end of a suitable hearing-tube. The open end of this tube is applied to the ear, and a miniature repetition of the speaker's voice is heard.

Now, what is the action of the receiver? This is the most puzzling question. I will only venture to suggest a probable or approximate explanation, which further investigation must either confirm or refute.

When light falls upon any substance, it may be either reflected, absorbed, or transmitted, or all these in different degrees. If the substance is opaque, only reflection or absorption occurs. The hard rubber reflects a little, and absorbs much, of the light it receives. But what happens to the rubber when such absorption takes place? The light disappears altogether as light, and is converted into heat