The marvel of the infinite number of stars is not so marvellous as the rationality that fain would comprehend them.  In seeking other minds than ours we seek for what is almost infinitely complex and coordinated in a material universe relatively simple and heterogeneous.  In our mental attitude towards the great question, this fact must be regarded as fundamental.

I can only fitly close a discourse which has throughout weighed the question of the living thought against the unthinking laws of matter, by a paraphrase of the words

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of a great poet when he, in higher and, perhaps, more philosophic language, also sought to place the one in comparison with the other.[1]

Richter thought that he was—­with his human heart unstrengthened—­taken by an angel among the universe of stars.  Then, as they journeyed, our solar system was sunken like a faint star in the abyss, and they travelled yet further, on the wings of thought, through mightier systems:  through all the countless numbers of our galaxy.  But at length these also were left behind, and faded like a mist into the past.  But this was not all.  The dawn of other galaxies appeared in the void.  Stars more countless still with insufferable light emerged.  And these also were passed.  And so they went through galaxies without number till at length they stood in the great Cathedral of the Universe.  Endless were the starry aisles; endless the starry columns; infinite the arches and the architraves of stars.  And the poet saw the mighty galaxies as steps descending to infinity, and as steps going up to infinity.

Then his human heart fainted and he longed for some narrow cell; longed to lie down in the grave that he might hide from infinity.  And he said to the angel: 

“Angel, I can go with thee no farther.  Is there, then, no end to the universe of stars?”

[1] De Quincy in his System of the Heavens gives a fine paraphrase of “Richter’s Dream.”

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Then the angel flung up his glorious hands to the heaven of heavens, saying “End is there none to the universe of God?  Lo! also there is no beginning.”

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THE LATENT IMAGE [1]

My inclination has led me, in spite of a lively dread of incurring a charge of presumption, to address you principally on that profound and most subtle question, the nature and mode of formation of the photographic image.  I am impelled to do so, not only because the subject is full of fascination and hopefulness, but because the wide topics of photographic methods or photographic applications would be quite unfittingly handled by the president you have chosen.

I would first direct your attention to Sir James Dewar’s remarkable result that the photographic plate retains considerable power of forming the latent image at temperatures approaching the absolute zero—­a result which, as I submit, compels us to regard the fundamental effects progressing in the film under the stimulus of light undulations as other than those of a purely chemical nature.  But few, if any, instances of chemical combination or decomposition are known at so low a temperature.  Purely chemical actions cease, indeed, at far higher temperatures, fluorine being among the few bodies which still show