Page:Popular Science Monthly Volume 7.djvu/779

Rh, for the want of sufficient knowledge of the mathematics. Hence Prof. Newton's advice to the young student in almost any branch of science is to acquire, first of all, a knowledge of geometry, analysis, and mechanics, so that the main ideas in them shall ever be familiar to him, and their processes readily recalled. Throughout the chemical and physical sciences, the laws are more and more assuming a mathematical form.

The unwisdom of neglecting the mathematics is again seen by considering some of the problems which appear to be in their nature capable of a mathematical solution. To explain by the accepted laws of rational mechanics all the forces and motions of the ultimate particles of matter, of inorganic matter even, may well be beyond the powers of the human mind. But that some of these forces and motions will be explained, even at an early day, seems to be almost certain. So the essential differences in the chemical elements may not be beyond discovery and explanation. Each line in the spectrum has its definite place, and those places are the results of certain laws of structure of the substance that gives the spectrum, and of its consequent action upon the light which comes from or traverses the substance. The time seems near for a Kepler who shall formulate those laws, and for a "Principia" which shall unite them in their most general mathematical expression. In like manner, along the line which in astronomy and physics separates the unknown from the known, there are hundreds of questions whose solution, if attained, must be in part mathematical.

Prof. Newton then speaks of the rôle of the laws of quantity in the sciences of political economy, geology, biology, and psychology Coast-Survey Measurements.—We take from the Tribune the following brief abstract of Prof. Hilgard's paper on "Coast-Survey Measurements." The author described the work of measuring a primary base-line near Atlanta, Georgia. The work is liable to error chiefly from changes in the temperature and instability in the apparatus. As every error in the base vitiates all succeeding measures, in which any errors are necessarily multiplied, it will be seen what care was needed to insure accuracy. The results, obtained by methods which Prof. Hilgard described at length, were tested three times by a repetition of the measurement at different seasons of the year. The greatest error thus detected was a deviation from the average of about $1/1000000$of the whole. To increase the severity of the tests, one of the measurements was made backward. Another way of stating the possible error is that it would be a third of an inch in six miles. Already this system of measurement, which is purely American, has elicited high praise abroad, and it will probably be adopted by European governments in their surveys. In previous papers before the Association the superiority of the American method for ascertaining longitudes had been expounded, and this system is now substituted for all previous ones in Europe. The apparatus used will form a part of our centennial display.

Grasshopper Dinners.—Prof. Charles V. Riley read a paper on "Locusts as Food for Man." The introductory portion of this paper was historical, tracing the use of locusts as human food to the earliest times of which there is record. Among the Nineveh sculptures are representations of men carrying different meats to a place of feasting, and some of the men are carrying sticks on which locusts are tied. In the book of Leviticus the locust is classed with "clean meats," and elsewhere in the Bible this insect is spoken of as food for man. Herodotus mentions a locust-eating tribe in Ethiopia, and Livingstone witnesses to the existence of this habit among modern African tribes. Even in the cities of Morocco, locusts are offered for sale in the markets and eating-houses. Many American tribes use this insect for food. In Southern Russia the locusts are salted and smoked; in Morocco they are boiled and then fried. Prof. Riley has had the locust cooked in a variety of ways, in order to test its flavor. This he pronounces "quite agreeable." Fried or roasted in their own oil, they have, he says, a pleasant, nutty flavor.

The Gar-Pike.—Several papers were read by Prof. Wilder, of Cornell University, who has spent the summer in the West. Of