Take any year which is not leap year, then, by passing over eleven years, we either leave Easter day unaltered, or throw it back a week; and it is nearly three to one that we have to leave it unaltered. Thus 1941 is not leap year, and eleven years more give 1952; both have April 13 for Easter day; but of 1943 and 1954, the first gives April 25, the second April 18.
Take any year which is leap year, then, by passing over eleven years, we either throw Easter one day forward, or six days back; and it is about three to two that it will be thrown forward. Thus 1852 (leap year) gives April 11, but 1863 gives April 5.
But when, in passing over eleven years, we pass over 1700, 1800, or any Gregorian omission of leap year, the common year takes the rule just described for leap year; while, if we begin with leap year, the passage over eleven years throws Easter two days forward, or five days back. There is another class of single exceptions, occurring at long intervals, which it is hardly worth while to examine. The only case which occurs between 1582 and 2000, is when the first year is 1970.
Any number of instances may be taken from my Book of Almanacs, and the general rule may be easily seen to belong also to the old style. Those who understand the construction of the calendar will very easily find the explanation of the whole.
A. DE MORGAN.
INEDITED LETTERS OF SWIFT.
[By the great kindness of a correspondent who has placed at our disposal two hitherto inedited letters written by Swift, we are enabled to present the following literal copies of them to our readers.
They are obviously addressed to Frances Lady Worsley, only daughter of Thomas Lord Viscount Weymouth, and wife of Sir Robert Worsley, Baronet, and the mother of Lady Carteret. In Sir Walter Scott's edition of Swift's Works (vol. xvii. p. 302.) will be found one letter from the Dean of St. Patrick to Lady Worsely; and in vol. xviii. p. 26. is the letter from that lady to the Dean which accompanied the escritoire alluded to in the second of the two letters which we now print. This appears from Swift's endorsement of it—"Lady Worsley, with a present of a writing-box japanned by herself.">[
"Madam,—It is now three years and a half since I had the Honor to see Your Ladyship, and I take it very ill that You have not finished my Box above a Month. But this is allways the way that You Ladyes treat your adorers in their absence. However upon Mrs. Barber's account I will pardon You, because she tells me it is the handsomest piece of work she ever saw; and because you have accepted the honor to be one of her protectors, and are determined to be one of her principall recommenders and encouragers. I am in some doubt whether envy had not a great share in your work, for you were I suppose informed that my Lady Carteret had made for me with her own hands the finest box in Ireland; upon which you grew jealous, and resolved to outdo her by making for me the finest box in England; for so Mrs. Barber assures me. In short, I am quite overloaden with favors from Your Ladyship and your Daughter; and what is worse, those loads will lye upon my Shoulders as long as I live. But I confess my self a little ungrateful, because I cannot deny Your Ladyship to have been the most constant of all my Goddesses, as I am the most constant of all your Worshippers. I hope the Carterets and the Worsleys are all happy and in health, and You are obliged to let Sir Robert Worsley know that I am his most humble Servant; but You need say nothing of my being so long his Rival. I hear my friend Harry is returning from the fiery Zone, I hope with more money than he knows what to do with; but whether his vagabond Spirit will ever fix is a question. I beg your Ladyship will prevail on Sr Robert Worsley to give me a Vicarage in the Isle of Wight; for I am weary of living at such a distance from You. It need not be above forty pounds a year.
"As to Mrs. Barber, I can assure you she is but one of four Poetesses in this town, and all Citizens' wives; but she has the vogue of being the best: yet one of them is a Scholar, and hath published a new edition of Tacitus, with a Latin dedication to My Lord Carteret.