KNIGHT AND CO., 90, FLEET STREET. Price One Shilling, stitched in a Wrapper; or, bound in cloth with the 'Companion to the Almanac,' Four Shillings. LONDON: PRINTED BY W. CLOWES AND SONS, STAMFORD STREET AND CHARING CROSS. EXPLANATORY NOTICES. Explanation of the column headed "Meridian Passage or Southing of the planets Venus and Jupiter." THE Thermometrical Register, showing the highest and lowest temperature of the corresponding month of the preceding year, has been discontinued in the British Almanac in order that the space occupied by it might be devoted to matter more belonging to the coming year. It has, therefore, been replaced by the Meridian Passage of Jupiter and Venus, that is to say, the time indicated by a clock showing mean time when those bright planets bear true south. Explanation of the columns headed "Length of day." "Day's increase or decrease,” "Day breaks," and "Twilight ends." THE column headed "Length of day" contains the number of hours and minutes between sunrise and sunset. The column headed "Day's increase" expresses the number of hours and minutes which the day has increased since the shortest day; and, where the column is headed "Day's decrease," it expresses the number of hours and minutes which the day has decreased since the longest day; for example, the length of the longest day in 1864 is put down in the column "Length of day" at 16h. 34m.; and on the 6th of July following we find that the length of the day, or the number of hours and minutes between sunrise and sunset, is set down at 16h. 23m.; hence the day has decreased 11m. since the longest day, and, accordingly, in the column "Day's decrease," we find opposite July the 6th, Oh. 11m. Equation of Time. In this Almanac the calculations are all made for mean time (given by the clock), instead of apparent time (given by the sun-dial), which latter had been used up to the year 1833. It must be obvious that, for all practical purposes, mean time is the most useful; and to obtain it from apparent time, the columns in the Almanac headed "Equation of Time" should be used. The column "Equation of Time" ought, for example, to be consulted when persons are desirous of setting their clock by a sun-dial. When clock after sun is written above the number of minutes and seconds opposite to the day, then the clock ought to be set so much slower than the sun-dial, and the contrary. Moonlight. THE Moon's age is set down in days and the nearest tenths of days from the time of change. Thus it is New Moon on the 9th of January at 7h. 46m. morning, and therefore at noon of the 10th she is 28h. 16m. old, which is set down as one and two-tenths. The fraction of the day of course continues the same throughout the lunation. LIST OF THE CORRESPONDENCE OF ERAS WITH THE YEAR 1864. [In those Eras which begin with the Christian year, the year alone is stated; in those which begin at a different season, the month in which the 1st of January, 1864, occurs is also given.] Correspondence with 1864. 22nd Thebet 5624 6577 1580 Abbreviations. A.M. Ær. Diocl. Ær. Seleuc. Persian Era of Yezdegird III. (Parsee account) Armenian common year.. Hegira Vikramaditya ........ Poos or Margaly 1920 Chinese Year 11th month of Kwei Hae. Samvat. VARIATION OF THE COMPASS, or the deviation of the magnetic or mariner's needle from the meridian or true north and south line at the undermentioned places in the United Kingdom, estimated for the 1st of January, 1864. N.B.-The variation is westerly, and is found to be decreasing in the United Kingdom about 6' annually. Scilly Islands, 23° 38'; Falmouth, 220 59'; Plymouth, 22° 42'; Portland, 21° 53'; Portsmouth, 21° 12'; Dover, 20° 13'; London, 20° 58'; Sunderland, 23° 12′; Edinburgh, 24° 3'; Glasgow, 24° 57'; Liverpool, 235 17; Pembroke, 23° 38'; Holyhead, 24° 8'; Dublin, 24° 54'; Belfast, 25° 18'; Galway, 26° 24'; Cork, 25° 36'. AUXILIARY TABLE FOR FINDING THE TIME OF SUNRISING AND SETTING. The time of Sunrise and Sunset in the British Almanac' is adapted to the parallel of latitude in which London is situated-viz. 51° 30'. THE following table has been constructed to show the variations of time through the United Kingdom-namely, between the latitude of 580 and 50° 10' N. The times of sun-rising and sun-setting are computed for the instant that the sun's centre is even with the horizon of the sea. The number of minutes found in this table under the month-day, and in the required latitude, are to be applied to the time of sun-rising and setting found on that day in the Almanac; the result will be the time of his ising and setting at the place required.-Ex. At what time will the sun rise and t on May 21 at Edinburgh? The time of sunrise and sunset on that day in the Almanac is 4h. 2m. A.M., and 7h. 52m. P.M. In the tables in parallel of 56°, in which Edinburgh is found, and under May 21, are 23 minutes; which, subtracted from 4h. 2m., leaves 3h. 39m. for time of sunrise; and, added to 7h. 52m., gives 8h. 15m. for time of sun-setting. But at those places where instead of mean time at place* railway time is now used, which in Great Britain is Greenwich mean time, and in Ireland Dublin mean time, to the times of sun-rising and sun-setting, as deduced by the auxiliary table, the longitude in time must be applied thus:-For places in Great Britain whose longitude is west of Greenwich, to the time of sunrise or sunset ad the longitude in time, and to places whose longitude is east of Greenwich, subtract the longitude in time, the result will be the railway or Greenwich time that the sun rises or sets. The same rule is applicable to places in Ireland whose longitude is east or west of Dublin. N.B.-Longitude in arc, indicated by the signs • " (degrees, minutes, and seconds) is converted into longitude in time by reckoning 360° 24 h., 15° 1 h., and 1° = 4 m, Example :-On June 21st at Penzance, in latitude 50° 7' N. and longitude 5° 31′ W., what will be the railway time that the sun rises and sets? Sun rises. 8 ........ ........ 3 52 add 22 4 14 8 10 add 22 8 32 At London, or in lat. 51° 30', as by Table, page 25 3 44 Railway or Greenwich mean time The places which follow the different parallels are situate within 15 miles of latitude, either north or south of it. 580 0'-Dornoch, Tain, Dunrobin, Portenleik, Dunclaim. 57° 30'-Peterhead, Fraserburg, Banff, Elgin, Cromarty, Inverness, Applecross. 57° 0'-Aberdeen, Bervie, Braemar, Laggan, Corpach. 56° 30′-Forfar, Dundee, Perth, Comrie, Ardchattan. 56° 0'-Berwick, Haddington, Edinburgh, Linlithgow, Kinross, Stirling, Dumbarton, Glasgow. 55° 30'-Embleton, Jedburgh, Selkirk, Sanquhar, Lanark, Irvine, Ayr. 55° 0'-Newcastle, Morpeth, Carlisle, Annan, Dumfries, New Galloway, Wigton. 54° 30' Scarborough, Whitby, Hartlepool, Stockton, Richmond, Appleby, Cockermouth, Whitehaven, North part of Isle of Man. 540 0'-New Malton, York, Aldborough, Clitheroe, Lancaster, Preston. 53° 30'-Grimsby, Kingston-upon-Hull, Pontefract, Manchester, Wigan, Liverpool, Beaumaris, Holyhead. .530 0'-Lynn Regis, Boston, Lincoln, Nottingham, Derby, Stafford, Flint, Chester, Denbigh, Caernarvon, Harlech. 52° 30'-Yarmouth, Norwich, Thetford, Ely, Peterborough, Leicester, Coventry, Lichfield, Shrewsbury, Ludlow, Montgomery, Aberystwith. 520 0'-Ipswich, Colchester, Cambridge, Hertford, Bedford, Buckingham, Oxford, Gloucester, Worcester, Hereford, Monmouth, Brecon, Caermarthen, Cardigan, St. David's. 51° 30'-LONDON, Ramsgate, Canterbury, Rochester, Chelmsford, Windsor, Wallingford, Marlborough, Malmesbury, Bath, Bristol, Newport, Cardiff, Llandaff, Pembroke. 51° 0'-Dover, Winchelsea, Brighton, Guildford, Chichester, Winchester, Portsmouth, Southampton, Salisbury, Shaftesbury, Wells, Ilchester, Taunton, Bridgewater, Minehead, Barnstaple. 50° 30′-Newport (I. W.), Poole, Weymouth, Exeter, Ashburton, Totnes, Plymouth, Tavistock, Launceston, Bodmin, Camelford, Padstow. 50° 10' Truro, Falmouth, Helstone, Penzance. IRELAND. 550 0'-Carrickfergus, Antrim, Coleraine, Londonderry, Lifford, St. Johnstown. 54° 30′-Belfast, Killyleagh, Downpatrick, Armagh, Charlemont, Dungannon, Augher, Donegal, Ballyshannon, Enniskillen, Sligo. 54° 0'-Carlingford, Newry, Dundalk, Drogheda, Kells, Cavan, Belturbet, Carrick, Boyle, Castlebar, Killala. 53° 30'-Dublin, Swords, Naas, Athboy, Mullingar, Philipstown, Kilbeggan, Athlone, Roscommon, Lanesboro', Tulsk, Tuam, Ballinrobe. 53° 0'-Wicklow, Blessington, Baltinglass, Carlow, Athy, Kildare, Portarlington, Maryborough, Ballinakill, Banagher, Galway, Ennis. 520 30'-Newborough, Enniscorthy, Wexford, Kilkenny, Cullen, Clonmel, Cashel, Killmallock, Limerick, Askeaton. 520 0'-Waterford, Dungarvon, Youghal, Tallow, Lismore, Rathcormack, Cork, Mallow, Killarney, Tralee, Ardfert, Dingle. 51° 30'-Kinsale, Bandon, Clonakilty, Baltimore. * See page 2, Explanatory Notices, Equation of Time. B 2 HIGH WATER. The following List, showing the difference of Time, nearly, between London and the Outports of the United Kingdom, as well as a few foreign Ports, is derived from Local Tide Tables and the best books on Navigation. To find the time of High Water at the above Places, it will be necessary to add or subtract the numbers in the above Table, according to the directions here given, to or from the time of High Water at London, as given in the Calendar for the day required. For example:-On the 1st of January, the morning High Water at London Bridge is 6h. 15m.; the High Water at Dover Harbour is 2h. 55m. earlier; subtract, according to the direction, 2h. 55m. from 6h. 15m., and the time of High Water at Dover Harbour on that day will be found to be at 3h. 20m. in the morning. |