This brief survey of the popular months of the European peoples is instructive from the point of view of a comparison with the names of months among primitive peoples. Although the Julian months have a fixed position in the solar year, and do not fluctuate to and fro like the lunar months, yet the names of the months are unstable and fluctuating. This is due to the fact that in the desire for concrete observations the names of the seasons and of their occupations have been kept, and the seasons have neither fixed position nor duration: these names of months derived from natural phenomena and occupations have not therefore in themselves the precision which the chronological system demands. Such precision will only be introduced by an external factor, in the one case by the lunar months, in the other by the Julian months to which the names of the seasons are transferred. CHAPTER XII. SOLSTICES AND EQUINOXES. AIDS TO THE DETERMINATION OF TIME. We have seen in the foregoing pages how the phases of Nature, with their somewhat variable dates, are everywhere employed in the determination of time; how in the moon there lies ready to hand a clear, stable (at least within very narrow limits), and constant unit of time which could be turned to account in calculating; and how out of the fusion of natural phases and moons there arose a roughly empirical lunisolar year. For the more accurate fixing both of the seasons and of the months the phases of the stars are employed; these, being dependent on the sun, keep pace with the natural year, but, unlike the phases of Nature, are not subject to climatic variations but are astronomically fixed. It is however possible astronomically to fix the solar year by a second method, viz. the observation of the annual course of the sun, especially of the solstices: the observation of the equinoxes is a much more difficult matter. The observation of the solstices can be performed in a way similar to that mentioned above, p. 21, in which noon is determined by the position of the sun, but is much more difficult to carry out and requires far more accurate and delicate methods. Two fixed points at least are necessary--a standing-ground and in the simplest case a mark on the horizon; other methods are still more complicated. An observation of the annual course of the sun, therefore, unlike that of the stars,--which everywhere, no matter where, can be performed immediately--demands a fixed place and special aids to determination. It follows that the observation of the solstices and equinoxes belongs to a much higher stage of civilisation than does that of the stars. It can only arise among a people with a fixed dwelling-place, since a race which leads a nomadic life and changes dwellings and camps is without the necessary fixed points of observation. After all it is only natural--and this actually is the case--that the observation of the course of the sun should be in use only among certain specially gifted peoples.