A HISTORY OF SCIENCE 



new year's day nearest the accession, and to call the 

 period between the accession day and the first new 

 year's day 'the beginning of the reign,' when the year 

 from the new year's day was called the first year, and 

 the following ones were brought successively from it. 

 Notwithstanding, in the dates of several Assyrian and 

 Babylonian sovereigns there are cases of the year of 

 accession being considered as the first year, thus giving 

 two reckonings for the reigns of various monarchs, 

 among others, Shalmaneser, Sennacherib, Nebuchad- 

 rezzar." 9 This uncertainty as to the years of reckon- 

 ing again emphasizes the fact that the solar year did 

 not have for the Assyrian chronology quite the same 

 significance that it has for us. 



The Assyrian month commenced on the evening 

 when the new moon was first observed, or, in case the 

 moon was not visible, the new month started thirty 

 days after the last month. Since the actual lunar 

 period is about twenty-nine and one-half days, a prac- 

 tical adjustment was required between the months 

 themselves, and this was probably effected by counting 

 alternate months as only 29 days in length. Mr. R. 

 Campbell Thompson 10 is led by his studies of the astro- 

 logical tablets to emphasize this fact. He believes 

 that "the object of the astrological reports which re- 

 lated to the appearance of the moon and sun was to help 

 determine and foretell the length of the lunar month." 

 Mr. Thompson believes also that there is evidence to 

 show that the interculary month was added at a period 

 less than six years. In point of fact, it does not ap- 

 pear to be quite clearly established as to precisely how 

 the adjustment of days with the lunar months, and 



