The third system was that of the sexagenary cycle. This was operated after the manner of a clock having two concentric dials, the circumference of the larger dial being divided into ten equal parts, each marked with one of the ten "celestial signs," and the circumference of the smaller dial being divided into twelve equal parts each marked with one of the twelve signs of the zodiac. The long hand of the clock, pointing to the larger dial, was supposed to make one revolution in ten years, and the shorter hand, pointing to the small dial, revolved once in twelve years. Thus, starting from the point where the marks on the two dials coincide, the long hand gained upon the short hand by one-sixtieth each year, and once in every sixty years the two hands were found at the point of conjunction. Years were indicated by naming the "celestial stem" and the zodiacal sign to which the imaginary hands happen to be pointing, just as clock-time is indicated by the minutes read from the long hand and the hours from the short. The sexagenary cycle came into use in China in 623 B.C. The exact date of its importation into Japan is unknown, but it was probably about the end of the fourth century A.D. It is a sufficiently accurate manner of counting so long as the tale of cycles is carefully kept, but any neglect in that respect exposes the calculator to an error of sixty years or some multiple of sixty. Keen scrutiny and collation of the histories of China, Korea, and Japan have exposed a mistake of at least 120 years connected with the earliest employment of the sexagenary cycle in Japan. The fourth method corresponds to that adopted in Europe where the number of a year is referred to the birth of Christ. In Japan, the accession of the Emperor Jimmu--660 B.C.--is taken for a basis, and thus the Occidental year 1910 becomes the 2570th year of the Japanese dynasty. With such methods of reckoning some collateral evidence is needed before accepting any of the dates given in Japanese annals. Kaempfer and even Rein were content to endorse the chronology of the Chronicles--the Records avoid dates altogether--but other Occidental scholars* have with justice been more sceptical, and their doubts have been confirmed by several eminent Japanese historians in recent times. Where, then, is collateral evidence to be found? *Notably Bramsen, Aston, Satow, and Chamberlain.