10 PREFATORY NOTE. [p^,™ 



REA0OP 

 HNOI.OQY 



prising four tlioussiud six liundred and seventeeu solar years, iudlcate 

 the delicacy of observatiou and the accuracy of record at the dawn of 

 civilization; even the Aztecs, neighbors, and kinfolk of the Mayas, 

 were said by Houzeau to have had a lunisolar calendar more exact 

 than the Julian calendar, though this is doubted by many. 



The real or apparent motions of the planets have also given rise to 

 calendaric elements, particularly in the astrologic and mystical systems 

 which have clung to the chronologic calendar in all stages of develop- 

 ment even up to the present time; and it has been suggested that plan- 

 etary elements enter subordinately into the Maya calendar. The plan- 

 etary calendar is not known, however, to alone form a useful basis for 

 chronology. 



Although the incommensurability of terrestrial .rotation and revolu- 

 tion is inconspicuous, yet when the observation of barbarous peoples is 

 sharpened by chronologic records based on the lunisolar calendar, they 

 perceive that the zenith or sunrise star of the new year gradually 

 changes its apparent position and slowly circles tlie heavens through 

 the centuries to resume its old relative j)osition in nearly a millennium 

 and a half; and thus a basis is afforded for a highly exact calendar, 

 independent of the eclipse cycle, which may be called sidero-solar. This 

 period is the Sothic cycle of the ancjient Egy])tians; and Zelia Nuttall 

 finds indications of its recognition by the ancient Aztecs, 



While all detinite calendars forming the basis of chronology among 

 primitive and cultured peoples have grown out of these astronomic 

 cycles, other elements have commonly been introduced. These elements 

 are of diverse character; days of rest or feasting are fixed through 

 religious observance and market days througli domestic needs, and 

 thus weeks of five, seven, thirteen, or some other number of days are 

 impressed on the calendar; seasons of j)lanting and harvesting, with 

 the times of feasting dependent thereon, come to be recognized through 

 their relations to agriculture, and are also impressed on the calendar; 

 and in some cases the time-periods for the maturing of crops and for 

 fetal develoi)ment appear also to enter the calendaric system. So 

 through the multiplication of astronomic bases and through the infu- 

 sion of artificial bases, the calendars of cultured peoples become highly 

 complex and long periods are required for their development. 



Among the results of this complexity of calendars may be mentioned 

 a tendency toward the development of mysticism, a tendency exem- 

 plified by the astrology of our own budding civilization and the hiero- 

 glyphics of Egypt and Yucatan, which were understood of the few only. 

 Indeed, even in our own day, though the calendaric bases are free to 

 all, it is but the few who take the time to comprehend them while the 

 many are con tent with the applications wrought out for their use. Thus 

 the development of calendars marks an early stage in that dift'erentia- 

 tion of function among individuals which began in savagery, waxed in 

 barbarism and earlier civilization, and culminates in enlightenment. 



