Benjamin Franklin, Poor Richard Improved:
It was the Egyptians, if we may credit Herodotus, that first formed the Year, making it to contain 360 Days, which they subdivided into twelve Months, of thirty Days each.
Mercury Trismegistus added five Days more to the Account. And on this Footing Thales is said to have instituted the Year among the Greeks. Tho’ that Form of the Year did not hold throughout all Greece. Add that the Jewish, Syrian, Roman, Persian, Ethiopic, Arabic, &c. Years, are all different.
In effect, considering the poor State of Astronomy in those Ages, it is no Wonder different People should disagree in the Calculus of the Sun’s Course. We are even assured by Diodorus Siculus, Plutarch, and Pliny, that the Egyptian Year itself was at first very different from what it became afterwards.
According to our Account, the Solar Year, or the Interval of Time in which the Sun finishes his Course thro’ the Zodiac, and returns to the same Point thereof from which he had departed, is 365 Days, 5 Hours, 49 Minutes; tho’ some Astronomers make it a few Seconds, and some a whole Minute less; as Kepler, for Instance, who makes it 365 Days, 5 Hours, 48 Minutes, 57 Seconds, 39 Thirds. Ricciolus, 365 Days, 5 Hours, 48 Minutes. Tycho Brahe, 365 Days, 5 Hours, 48 Minutes.
The Civil Year is that Form of the Year which each Nation has contrived to compute Time by; or the Civil is the Tropical Year, considered as only consisting of a certain Number of whole Days; the odd Hours and Minutes being set aside, to render the Computation of Time in the common Occasions of Life more easy.
Hence as the Tropical Year is 365 Days, 5 Hours, 49 Minutes; the Civil Year is 365 Days. And hence also, as it is necessary to keep Pace with the Heavens, it is required that every fourth Year consist of 366 Days, which would for ever keep the Year exactly right, if the odd Hours of each Year were precisely 6.
The ancient Roman Year, as first settled by Romulus, consisted of ten Months only; viz. I. March, containing 31 Days. II. April, 30. III. May, 31. IV. June 30. V. Quintilis, 31. VI. Sextilis, 30. VII. September, 30. VIII. October, 31. IX. November, 30. X. December, 30; in all 304 Days; which came short of the Solar Year, by 61 Days.
Hence the Beginning of Romulus’s Year was vague, and unfixed to any precise Season; which Inconvenience to remove, that Prince ordered so many Days to be added yearly, as would make the State of the Heavens correspond to the first Month, without incorporating these additional Days, or calling them by the Name of any Month.
Numa Pompilius corrected this irregular Constitution of the Year, and composed two new Months, January and February, of the Days that were used to be added to the former Year. Thus, Numa’s Year consisted of twelve Months; viz. I. January, containing 29 Days. II. February, 28. III. March, 31. IV. April, 29. V. May, 31. VI. June, 29. VII. Quintilis, 31. VIII. Sextilis, 29. IX. September, 29. X. October, 31. XI. November, 29. XII. December, 29; in all 355 Days, which came short of the common Solar Year by ten Days; so that its Beginning was vague and unfixed.
Numa, however, desiring to have it fixed to the Winter Solstice, ordered 22 Days to be intercalated in February every second Year, 23 every fourth, 22 every sixth, and 23 every eighth Year.
But this Rule failing to keep Matters even, Recourse was had to a new Way of Intercalating; and instead of 23 Days every eighth Year, only 15 were added; and the Care of the whole committed to the Pontifex Maximus, or High Priest; who, neglecting the Trust, let Things run to the utmost Confusion. And thus the Roman Year stood till Julius Caesar made a Reformation.
The Julian Year is a Solar Year, containing commonly 365 Days; tho’ every fourth Year, called Bissextile, contains 366. The Names and Order of the Months of the Julian Year, and the Number of Days in each, are well known to us, having been long in Use.
The astronomical Quantity, therefore, of the Julian Year, is 365 Days, 6 Hours, which exceeds the true Solar Year by 11 Minutes; which Excess in 131 Years amounts to a whole Day. And thus the Roman Year stood, till the Reformation made therein by Pope Gregory.
Julius Caesar, in the Contrivance of his Form of the Year, was assisted by Sosigenes, a famous Mathematician, called over from Egypt for this very Purpose; who, to supply the Defect of 67 Days which had been lost thro’ the Fault of the High Priests, and to fix the Beginning of the Year to the Winter Solstice, made that Year to consist of 15 Months, or 445 Days; which for that Reason is used to be called Annus Confusionis, the Year of Confusion.
This Form of the Year was used by all Christian Nations, till the Middle of the 16th Century; and still continues to be so by several Nations; among the Rest, by the Swedes, Danes, &c. and by the English till the second of September next, when they are to assume the Use of the Gregorian Year.