Page:Popular Science Monthly Volume 46.djvu/442

428 cities shall no longer convert the natural waterways into sewers, and the lakes into reservoirs for their sewage? Methods of sewage disposal and disinfection have been already so far perfected that, in my opinion, at no distant day, compulsory destruction of all offensive and dangerous waste material, of whatsoever kind, may be legally enforced without serious expense or inconvenience. Again, are we quite rational in the relative estimate we place upon our most cherished possessions? Do we not strangely, insanely underrate health and life, and overrate greatly the mere things which possess absolutely no value at all apart from life and health?" These conclusions are strikingly enforced in the lesson of the recent outbreak of typhoid fever at Wesleyan University, that has been traced to the eating of oysters raw which had been exposed to contamination in their temporary storage bed by a drain leading from a house where there was typhoid fever.

The Peopling of America.—In trying to account for the settlement of America by spontaneous migrations, Prof. O. T. Mason postulates that the emigrants would be drawn, in the quest for food, along the lines of most abundant supply and of least resistance. He accepts Morgan's location of the region about the mouth of the Columbia River as the starting point of the migration over the continent. Whence and how did men come to that point? He finds a route from Asia to America that might have been nearly all the way by sea, and continuously used for centuries; and which lies absolutely along a great circle of the earth, the shortest and easiest highway. This great circle route lies mostly through landlocked waters, and embraces, in order, the northeastern Indo-Malayan Archipelago, the South China and Malay Seas, the East China and Yellow Seas, the Japanese and Tartary Seas, the Okhotsk Sea and environs, the Bering Sea with its bays, the Alaskan Sea and inlets, the Tlinget-Haide Sea, the Vancouver Sea, and the Columbia Basin. The same great circle would go on to include the head waters of all the Rocky Mountain streams, the great interior basin, the Pueblo region, Mexico, Central America, Ecuador, and Peru. Along it food is abundant, no point is at a very great distance from land, and all the conditions are as favorable as could be found anywhere to the success of a voyager. Hence Prof. Mason advances the hypothesis that during the centuries in which Europe was working out of its earliest stone age into its renascence, certainly for three thousand years or more, America was being steadily and continuously peopled from Asia by way of its eastern shores and seas from the Indian Ocean. Subsidiary movements in the way of offshoots from this migration, contributions to it, and barriers to its progress took place up and down the rivers and in the seas of India, China, Mongolia, and Siberia. The author disclaims any reliance upon theories of sunken continents, upon voyages across the profound sea without food or motive, the accidental stranding of junks, or the aimless wandering of lost tribes; assumes that there never was known to history a day when the Asiatic and American continents were not intimately associated; and concludes that "when the continent of America was peopled it was done by men and women purposely engaged in what all sensible people are now doing—namely, trying to get all the enjoyment possible out of life for their efforts."

The Critical Faculty in Engineering.—The presidential address of Prof. A. B. W. Kennedy, of the Section of Mechanical Science, in the British Association, was devoted to the critical side of mechanical training—the training to think about a subject, to write upon it, and to come to a rational decision, by exercising a critical sense of proportion which could be best developed by a course of quantitative experimental work in an engineering laboratory. After observing that an engineer was a man who was continually called upon to make up his mind irrevocably in a very short time—generally about one tenth of the time which he would like to give to the subject—the author pointed out that there was an essential difference between the problems of the mathematician and those of the engineer. In pure science and mathematics there was little room for the critical faculty—the result was either right or wrong. In engineering there might be many solutions, and the critical faculty must be rapidly supplied to the