ROGER BACON. 87 



the 25th of March, since Ptolemy for the year 140 fixed 

 it on the 22nd of that month ; still less can it be as it is 

 reckoned to-day on the 2 1st according to Church usage; in 

 reality it comes about the I3th, since it advances by one day 

 in 124 years. The Equinoxes then are not fixed occurrences 

 in the first place, and in the second place they do not come 

 on the days indicated by the Church." 



We see that Roger Bacon indicated both the necessity 

 and the nature of the reform with perfect clearness and 

 precision. The Arabs, before him, had determined, it is 

 true, the length of the year to be 365 days 5 hours 48 

 minutes 1 1 seconds ; but the fact remains that Roger Bacon 

 had acquainted himself with all the elements of the problem, 

 and by dint of observation and calculation, solved it with 

 remarkable sagacity. Nor was he less exact and sagacious 

 in correcting errors in reference to lunations : . 



" The present Calendar," says he, " wrongly indicates new 

 moons ; in 76 years the new moon anticipates the period 

 fixed by the Calendar by 6 hours 40 minutes ;* so that at the 

 end of 356 years the error will amount to one entire day/' 

 And adding other errors to that one, he shows that after 4,266 

 years there will be full moon in the heavens, and new moon 

 in the Calendar. His petition to the Pope to reform the 

 Calendar ends by the following appeal : " A reform is 

 necessary; men trained in calculation and astronomy are 

 aware of it, and rail at the ignorance of the prelates who 

 maintain the present conditions. Unbelieving philosophers, 

 Arabian and Hebrew, the Greeks who live among Christians, 

 as in Spain, Egypt, and eastern countries, and elsewhere too, 

 have in horror the stupidity which the Christians exhibit in 

 their chronology and the celebration of their feasts. And yet 

 the Christians have at present enough of astronomical 

 knowledge to rely upon a safe basis. Let Your Reverence 

 command it, and you will find men who will be able to 

 remedy these defects those I have spoken of, and others 

 besides there are thirteen in all without counting their 

 infinite ramifications. If this glorious work were to be 

 accomplished in the time of Your Holiness, men would see 

 * More precisely, 6 hours 8 minutes. 



