122 MEMOIR EXPLANATORY OF A NEW PERPETUAL CALENDAK. 



must cither be in error, or that the month has been, by some inadvertence, misquoted from 

 his Table by Delambre. The day (or quantiemc) of the month is the same, according to all 

 the mathematicians thus far named, and the month must be April, for the 22d of March 

 corresponds with Thursday, and not with Sunday, in that year, and the Paschal New Moon 

 cannot happen in March when the Epact exceeds 23. It seems no less unaccountable, that 

 Sir Harris Nicolas, who gratefully acknowledges some assistance from Mr. De Morgan, 

 when preparing his " Chronology of History," published in 1833, in Lardner's Cabinet 

 Cyclopedia, should make the Easter of 3860, by the number of direction in his Table H, 

 to be the 15th of April, — just a week earlier than my instructors have computed it, and yet 

 not agreeing with Clavius's decision, as before reported. I shall be glad if the pointing 

 out of this strange discrepancy should lead to the removal of a radical error existing 

 somewhere, and, as I believe, in Vince's Complete System of Astronomy, vol. 1, page 581, 

 in Ferguson's Astronomy, and in Rees's Cyclopedia, (Article "Cycle,") in all of which, 

 as well as in many other scientific and popular works of reference, a like Table, con- 

 taining numbers of Direction, (so called,) said to be " adapted to the New Style," is given, 

 but in terms unsanctioned by those later and abler Analysts whom I have consulted, and 

 on whose principles I have relied. Certain it is, that Sir H. Nicolas's Tables, H and K, 

 (pages 57 and 58, Edition II.,) are entirely at variance with each other in regard to the 

 Easter day of every year having the Golden Number 14, (or Epact 24,) between 1590 

 and 1685, both inclusive; and it is equally true that Delambre's formula) do not authenti- 

 cate the Easters of any year having the Golden Number 4, (or Epact 24,) from 3803 to 

 3898, both inclusive, as calculated by Sir H. Nicolas's Table H. In these last cases 

 the deviation varies from one to two weeks; in the former, it amounts always to four 

 weeks. 



The learned Benedictine of St. Maur, who, between the first and third edition of "The 

 Art of Verifying Dates," discovered the means of reducing his " Perpetual Solar Calendar" 

 from 210 folio pages, which he had confessed to be rather voluminous, to its present bulk 

 of 42, makes the following truly philosophical reflection: "Tel est le sort des inventions 

 humaines, de n' etre pcrfectionnees que par degres, et presque jamais du premier coup." 

 Then, after explaining by what expedients he had accomplished so important an abridg- 

 ment, he congratulates himself and the public on his great success, and finishes, by say- 

 ing: "II est simple, il est court." On examining his work, it will be evident, that 64 of 

 Ins p;igcs arc essentially replaced by the single one forming my Tablet, which may, con- 

 sequently, with more truth be characterised as " simple and short," without being found, 

 I trust, the less sure.* 



* N. B. — The words "in Julian Vears," standing at the close of the Exception to the General Rule for find- 

 ing the Epact, wire inadvertently omitted in the Tablet, as printed in the Quarterly Proceedings of 1845. This 

 Erratum, (for the exception was not meant to he applied to Gregorian Years,) grew out of a change made by me, 

 with a view to brevity, hut without due care, in the terms of the original manuscript, which directed "that every 

 zero resulting from the division of the sum by 30 should be called XXX. in New Style, but XXIX. in Old," — a 

 restriction exactly equivalent lo the one here prescribed, and that by which all the computations connected witli 

 my dr\ice were really governed. 



