attain some practical end, and in later stages also the same object still holds an important place. The desire to observe religious festivals regularly has stimulated the study of astronomy in order to obtain exact measurements of time. Among the Hindoos mathematics was stimulated by the requirements of religious worship in making their altars and laying out their courts. And according to Max Mueller[1] they also struggled with the problem of making a square altar of the same size as a round one. In Egypt, geometry got its stimulus from the need of parcelling out the land fertilized by the Nile. The progress of architecture also increased man's knowledge of mathematics and physics. The great European cathedrals were built before scientific works upon architecture appeared. It is said that the needs of Alexander's campaigns in Persia stimulated the study of mathematics and physics. And the desire to save human life has always been a great stimulus to the study of biology. These are simply a few illustrations of the kind of stimuli which have been most potent in the advancement of science.
After science has attained a start, if social conditions are favorable, it will progress without the immediate incentive of a practical need. As knowledge advances men begin to recognize its general value and try to extend it in every direction, believing in its ultimate, if not in its immediate, usefulness to mankind. This is science for the sake of science and is represented by the present period of scientific development. Such a method of increasing knowledge is never purely arbitrary, however. Not all truth is considered of the same value at a given epoch. If scientists have not always in view some practical end, they are more likely to be interested in those departments of knowledge which have a bearing on the immediate need of society. It will be observed, therefore, that this last influence, science for the sake of science, is not wholly separated from the preceding one, science for the sake of art, although a new motive is present. In addition to the need of solving an immediate problem, the value of all positive knowledge is recognized and becomes a new incentive in stimulating a study of the sciences.
With this brief enumeration of the chief causes of the progress of science, we may turn to the consideration of the conditions under which the pursuit of science is most likely to flourish. It seems probable that science is somewhat more likely to advance, at least after a start has been made, in cold or in temperate climates, than in warm climates. According to Professor Cattell's "Study of Eminent Men"[2] France has produced the largest number of scientists of any country, and England the next largest. This order is true not only in the absolute number, but
