Page:Encyclopædia Britannica, Ninth Edition, v. 4.djvu/750

Rh 678 CALENDAR [HEBREW. The calendar is constructed on the assumptions that the mean lunation is 29 days 12 hours 44 miu. 3J sec., and that the year commences on, or immediately after, the new moon following the autumnal equinox. The mean solar year is also assumed to be 365 days 5 hours 55 min. 25f-y sec., so that a cycle of nineteen of such years, con taining 6939 days 16 hours 33 min. 3 sec., is the exact measure of 235 of the assumed lunations. The year 5606 was the first of a cycle, and the mean new moon, appertain ing to the 1st of Tisri for that year, was 1845, October 1, 15 hours 42 min. 43^ see., as computed by Lindo, and adopting the civil mode of reckoning from the previous midnight. The times of all future new moons may conse quently be deduced by successively adding 29 days 12 hours 44 min. 3J sec. to this date. To compute the times of the new moons which determine the commencement of successive years, it must be observed that in passing from an ordinary year the new moon of the following year is deduced by subtracting the interval that twelve lunations fall short of the corresponding Gregorian year of 365 or 366 days ; and that, in passing from an embolismic year, it is to be found by adding the excess of thirteen lunations over the Gregorian year. Thus to deduce the new moon of Tisri, for the year immediately following any given year (Y), when Y is ( ordinary, subtract days 15 hours 11 min. 20 sec., I /18 f embolismic, add ( ,- j days 21 hours 32 min. 43^ sec., the second-mentioned number of days being used, in each case, whenever the following or new Gregorian year is bis sextile. Hence, knowing which of the years are embolismic, from their ordinal position in the cycle, according to the rule before stated, the times of the commencement of successive years may be thus carried on indefinitely without any difficulty. But some slight adjustments will occasionally be needed for the reasons before assigned, viz., to avoid certain festivals falling on incompatible days of the week. Whenever the computed conjunction falls on a Sunday, Wednesday, or Friday, the new year is in such case to be fixed on the day after. It will also be requisite to attend to the following conditions : If the computed new moon be after 18 hours, the following day is to be taken, and if that happen to be Sunday, Wednesday, or Friday, it must be further postponed one day. If, for an ordinary year, the new moon falls on a Tuesday, as late as 9 hours 11 min. 20 sec., it is not to be observed thereon ; and as it may not be held on a Wednesday, it is in such case to be postponed to Thursday. If, for a year immediately following an embolismic year, the computed new moon is on Monday, as late as 15 hours 30 min. 52 sec., the new year is to be fixed on Tuesday. After the dates of commencement of the successive Hebrew years are finally adjusted, conformably with the foregoing directions, an estimation of the consecutive intervals, by taking the differences, will show the duration and character of the years that respectively intervene. According to the number of days thus found to be com prised in the different years, the days of the several months are distributed as in Table VI. The signs + and - are respectively annexed to Hesvan and Kislev to indicate that the former of these months may sometimes require to have one day more, and the latter sometimes one day less, than the number of days shown in the table, the result, in every case, being at once determined by the total number of days that the year may happen to contain. An ordinary year may comprise 353, 354, or 355 days ; and an embolismic year 383, 384, or 385 days. In these cases respectively the year is said to be imperfect, common, or perfect. The intercalary month, Veadar, is introduced in embolismic years in order that Passover, the 15th day of Nisan, maybe kept at its proper season, which is the full moon of the vernal equinox, or that which takes place after the sun has entered the sign Aries. It always precedes the following new year by 163 days, or 23 weeks and 2 days ; and Pentecost always precedes the new year by 113 days, or 16 weeks and 1 day. TABLE VI. Hebrew Months. Hebrew Ordinary Embolismic Month Year Year Tisri 30 30 Hesvan 29 + 29 + Kislev 30- 30- Tebet 29 29 Sebat 30 30 Adar 29 30 (Veadar) (...) (29) Nisan 30 30 Yiar 29 29 Sivan 30 30 Tamuz 29 29 Ab 30 30 EM 29 29 Total 354 384 The Gregorian epact being the age of the moon of Tebet at the beginning of the Gregorian year, it represents the day of Tebet which corresponds to January 1 ; and thus the approximate date of Tisri 1, the commencement of the Hebrew year, may be otherwise deduced by subtracting the epact from Sept. 24 ) ,, ( ordinary ) TT, 4 &amp;gt; after an &amp;lt; IT- r Hebrew year. Oct. 24 j ( embolismic ) The result so obtained would in general be more accurate than the Jewish calculation, from which it may differ a day, as fractions of a day do not enter alike in these com putations. Such difference may also in part be accounted for by the fact that the assumed duration of the solar year is 6 min. 39f4 sec. in excess of the true astronomical value, which will cause the dates of commencement of future Jewish years, so calculated, to advance forward from the equinox a day in error in 216 years. The lunations are estimated with much greater precision. The following table is extracted from Woolhouse s Measures, Weights, and Moneys of all Nations : TABLE VII. Helreiv Years. Jewish Year. Num ber of Days. Commencement (1st of Tisri). Jewish i Year. Num ber of Days. Commencement (1st of Tisri). 5606 354 Thur. 2 Oct. 1845 5625 355 Sat. 1 Oct. 1864 07 355 Hon. 21 Sept. 1846 26 354 Thur. 21 Sept. 1865 08 383 Sat. 11 Sept. 1847 27 385 Mon. 10 Sept. 1866 09 354 Thur. 28 Sept. 1848 28 353 Mon. 30 Sept. 1867 10 355 Mon. 17 Sept. 1349 29 354 Thur. 17 Sept. 1868 11 385 Sat. 7 Sept. 1850 30 385 Mon. 6 Sept. 1869 12 353 Sat. 27 Sept. 1851 31 355 Mon. 26 Sept. 1870 13 384 Tues. 14 Sept. 1852 32 383 Sat. 16 Sept. 1871 14 1 355 Mon. 3 Oct. 1853 ^33 354 Thur. 3 Oct. 1872 1,15 355 Sat. 23 Sept. 1854 i .34 ! 355 Mon. 22 Sept. 1873 S 16 383 i Tlmr. 13 Sept. 1855 O or kj 00 383 Sat. 12 Sept. 1874 I 17 354 Tues. 30 Sept. 1856 36 355 Thur. 30 Sept. 1875 w 18 | 3f,5 Sat. 19 Sept. 1857 ^37 354 Tues. 19 Sept. 1876 19 385 Thur. 9 Sept. 1858 38 385 Sat. 8 Sept. 1877 20 354 Thur. 29 Sept. 1859 39 355 Sat. 28 Sept. 1878 21 353 Mon. 17 Sept. 1860 40 354 Thur. 18 Sept. 1879 2 2 385 Tlmr. 5 Sept. 1861 41 383 Mon. 6 Sept. 1880 23 354 Thur. 25 Sept. 1862 42 355 Sat. 24 Sept. 1881 24 383 Mon. 14 Sept. 1863 43 383 Thur. 14 Sept. 1882