The book of almanacs, with and index by which the almanac may be found for every year up to A.D. 2000. With means of finding the day of any new or full moon from B.C. 2000 to A.D. 2000 / compiled by Augustus de Morgan.

  • De Morgan, Augustus, 1806-1871.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The book of almanacs, with and index by which the almanac may be found for every year up to A.D. 2000. With means of finding the day of any new or full moon from B.C. 2000 to A.D. 2000 / compiled by Augustus de Morgan. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    begins in the next Christian year. But sometimes a wliole Hegiral year is contained within a Christian year (beginning in January and ending in December), so that two successive Hegiral years begin in one and the same Christian year. To state wlieu this happens will enable the reader, so far as year-dates are concerned, to convert Mahometan dates into Christian, and the converse. OLD STYLE. NEW STYLE. A. HEG. A.Ii. A. HEG. A.D. A. HEG A.D. A. HEG. A.D. 19-20 640 455-456 1063 891-892 i486 993-994 1585 52-53 072 488-489 1095 925-926 1519 1026-1027 1617 86-87 705 522-523 1128 958-959 I551 1060-1061 1650 I 19-120 737 555-556 7 160 992-993 1584 1093-1094 1682 153-154 77° 589-590 JI93 1025-1026 1616 1127-1128 1715 186-187 802 623-624 1226 IO59-I060 1649 1161-1162 1748 220-221 656-657 1258 1092-1093 i68i 1194-1195 1780 254-255 868 690-69 I I29I II26-I127 1714 1228-1229 1813 287-288 900 723-724 1323 I ]6o-n6i 1747 1261 1262 1845 321-322 933 757-758 1356 1193-1194 1779 1295-1296 1878 354-355 965 790-791 1388 1227-1228 1812 191 I 3S8-389 998 824-825 142 I 1260-1261 1844 1362-1363 1943 421-422 1030 858-859 1454 1396-1397 1976 This table shows, for instance, that the Hegiral years 186 and 187 both begin in a.d. 802. To find the year a.d. in which a given year a. heg. begins, count year for year from the last Hegiral year of the pair in the above table which precedes the given Hegiral year. Thus (New Style) a. heg. 1169, seven years in date from 1162, begins seven years in date from 1748, or in 1755. To find the year a.11. in which a year a. d. begins, reverse the preceding process, and subtract one from the result. Thus, to know where A.D. 1693 begins, 11 years in date from 1682 in the table, add 11 to 1094 and subtract i, wliich gives 1104. To find roughly the month in which a given year a. heg. begins, subtract the latter date of the last two which begin in our year a.d., and choose the month written opposite the remaining number in the following list, always taking January and December for the commencements of the pairs in the list. 31, 32 January. 20, 21, 22 ISlay. 9, 10, 11 September. 28, 29, 30 Fuliiuavv. 17, 18, 19 June. 6, 7, 8 October. 25, 26, 27 IMrticli, 14, 15, 16 July. 3, 4, 5 November. 23, 24 April. 12, 13 August. i, 2 December. This will be right within a month, and is all that can be done without calculation or an e.xtensive table. Thus the year 1172 of the Hegira (10 removed from 1162) begins in September, by tiiis rule (the true beginning is September 4). The middle numbers are sure enough to give the real month ; the extremes not so safe. Thus 16 may be June or July.