Page:Popular Science Monthly Volume 33.djvu/96

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THE POPULAR SCIENCE MONTHLY.

now, it has become necessary to purge religious belief of dross in the form of trivialities and superstitions. This has ever been and ever will be the function of science. The essentials of religious faith it does not, it can not, touch, but it purifies and ennobles our conceptions of Deity, and thus elevates the whole plane of religious thought.

It will not, of course, be expected of me to give, even in briefest outline, a system of reconstructed Christian thought. Such an attempt would be wholly unbecoming. Time, very much time, and the co-operation of many minds, bringing contributions from many departments of thought, are necessary for this. In a word, it can only itself come by a gradual process of evolution. But from the point of view of science some very fundamental changes in traditional views are already plain. Of these the most fundamental and important are our ideas concerning God, Nature, and man in their relations to one another.

SOUND-SIGNALS AT SEA.
By ARNOLD BURGES JOHNSON.

THE difficulty in determining the true and exact direction of the sounds we hear meets us in various ways. The hunter hears the note of a bird, the hiss or whistle of a deer, and the sound indicates identity and proximity but not direction. The hunter waits for repeated renewal of the sound to ascertain its exact position, and even then verifies his audition by his vision. The hunter by his camp-fire may aim between the luminous dots of reflected light, which he knows to be the eyes of a wolf; but he would scarcely be able to aim at or even very near that spot on simply hearing the howl from the wolf that owns the eyes.

The plainsman hears a shout in the distance. He may recognize it as the voice of a comrade, and fix the general direction as north, east, south, or west, but hardly more. He may shout back, and the two may come together; but if it be dark and there is no fire or other signal, the shouting back and forth must be frequently repeated, and varied from a simple to a complex sound, that each may correct the error of his own audition, eliminate his personal equation, and the sound will appear to swing, pendulum-like, right and left, with shorter and shorter stroke, till the comrades come together.

The average child, returning from school, on entering the house calls, "Mamma!" The mother, perhaps, replies, "Yes!" "Where are you?" is the next question, and the reply informs the child not only as to the floor, but as to the room in which