Page:Popular Science Monthly Volume 45.djvu/279



Editor Popular Science Monthly:

late numbers of this journal public attention has been called to errors in the statement of facts or of scientific points, by men who should have known better. But errors of the kind you name are not confined to a few, but are found everywhere—even among poets and artists, as well as among men of science.

Some years ago a French artist was employed to paint a panel on the west wall of the room belonging to a lodge. He made a beautiful evening landscape, having the sun in the horizon. A little above, and toward one side, was the full moon. The shadows of the trees in the foreground all pointed to the moon as their source, although the whole circle of the sun was still in view. I called his attention to this want of conformity to the facts—but the picture was too good to be spoiled by corrections; so it remained as it was made.

There is a beautiful hymn by Seagrave, found in many church collections, having a part of a stanza as follows:

 Rivers to the ocean run. Nor stay in all their course; Fire, ascending, seeks the sun. Both speed them to their source"

[All the Italics in this letter are my own.] The science contained in these lines is that of the ancient heathen philosophy, viz., that things heavy naturally tend downward, things light naturally tend upward.

The attribute of intelligence thus given to the fire has but a sorry exemplification, seeing that all fires which burn in the night fail to get a right start in their search for the sun. Of course, it is meant that the fire goes upward of its own accord—is not driven by anything else.

A distinguished professor of physics in an Ohio college many years ago was accustomed to say in his lectures that "hot air rises, and the cold air rushes in to fill the vacuum." I once called his attention to the slip. He acknowledged the error—and then continued to speak as before, much after the manner of the devil when he was sick and wished to be a monk.

The same absurd statement appears in The Popular Science Monthly for last November, page 104, in the article on the origin of The Mississippi Valley Rainfall. We find as follows: "They [the winds] flow as on an inclined plane, over the colder and more dense air toward the north, and thus restore the equilibrium of the atmosphere that has been disturbed. This disturbance is caused by a continual flow of the cold and heavy surface air from the extreme north toward the equator, because along the tropical belt a partial vacuum is created by the air becoming heated and lighter, and in consequence floating upward, and the cold air rushes in to supply that vacuum." There it is.

Again, in the February number of this year, page 466, in the article on the Physical Conditions of the Deep Sea, occurs this passage: "The particles of water thus heated immediately commence to rise through the superjacent layers of colder water, and the colder particles would fall to take their places."

On the principles of the ancient philosophy these extracts are all right, but according to the principles of modern physics they are all wrong. Your own rebuke to such carelessness was well deserved—let us hope that it may produce needed reformation.

Editor Popular Science Monthly:

February number of The Popular Science Monthly has Just arrived, and I should like to add to the article on the Psychology of a Dog two illustrations.

When my father was in the navy during the late war, his ship, the United States bark Pursuit, lay at St. Joseph's Bay, Florida. There was on board a dog (half pointer) called "Secesh" because he had been captured from the "rebs." One day the men went on shore, taking "Secesh" with them, but when the time came to return the dog was nowhere to be seen, and the men were obliged to go back without him. Half an hour later Secesh appeared upon the beach and, finding the boat had gone, he started to swim for the vessel; but before he reached it the tide caught him and was carrying him rapidly out to sea; he thereupon swam back to the shore, trotted rapidly up the beach for a considerable distance, and again struck out for the ship, this time reaching it in safety.

Again: my grandmother was possessed of a small dog of no particular breed. One evening she, with my grandfather, was talking of going to visit her mother, some twenty miles distant, on the following day. Dick, the dog, lay on the hearth at their feet. My grandmother remarked that they had better shut Dick up before they started or he would follow them. In the morning Dick was nowhere to be found, and they were obliged to