ALLYL. 



ALMANAC. 



would result from calculation ; the following alloy* afford example* of 

 iaereMed and diminished density. 



Dimlniihcd. 

 and silver 



" i 1 ^ 



lead 



.. copi>er 



.. indium 



., nickel 



copper 



.. bismuth 



antimony 



lead 



lead 



.. palladium 



.. antimony 



., arsenic 



.. antimony 



Not only are the properties of metals altered by combination, but 

 different proportions of the same metals produce very different alloys. 

 Thus, by conil lining ninety parts of copper with ten parts of tin, an 

 alloy is obtained of greater density than the mean of the metals, and it 

 is also harder and more fusible than the copper ; it is slightly malleable 

 when slowly cooled, but on the contrary when heated to redness, and 

 plunged into cold water, it is very malleable : this compound ia known 

 by the name of bronic. If eighty parts of copper be combined with 

 twenty parts of tin, the compound is the extremely sonorous one called 

 Mi-metal ; an alloy consisting of two-thirds copper and one-third tin, 

 is susceptible of a very fine polish, and i used as tpeculum metal. 



It is curious to observe in these alloys, that in bronze, the density 

 and hardness of the denser and harder metal are increased by combining 

 with a lighter and softer one ; while, as might be expected, the fusibility 

 of the more refractory metal is increased by uniting with a more fusible 

 one. In bell-metal, the copper becomes more sonorous by combination 

 with a metal which is less so : these changes are clear indications of 

 chemical action. 



It has been already observed, that the natural alloys, considered as 

 such, are not important bodies ; the only one, if indeed that may be so 

 reckoned, is the alloy of iron and nickel, constituting meteoric iron, and 

 of which the knives of the Esquimaux appear to be made. The arti- 

 ficial metallic alloys are of the highest degree of utility : thus, gold is 

 too soft a metal to be used either for the purposes of coin or ornament, 

 it is therefore alloyed with copper ; silver, though harder than gold, 

 would also wear too quickly, unless mixed with copper ; and copper is 

 improved, both in hardness and colour, by combination with zinc, 

 forming brass. 



The following, among other useful alloys, will be treated of under 

 their specific names, viz., BELL-METAL, PEWTER, BRASS, BRONZE, GUN, 

 PRINCE'S, SPECULUM, BRITANNIA, and TYPE METAL, GERMAN SILVER, 

 NK-KEL SILVER, TuTENAO.and SOLDERS. Other alloys will be described 

 when the more important metal entering into their composition comes 

 under consideration. 



ALLYL. [ALCOHOLS ; ORGANIC RADICALS.] 



ALLYL SULPHOCARBAMIC ACID. [SULPHOSINAPIC ACID.] 



ALLYL, SULPHIDE OF. [GARLIC, OIL OF.] 



ALLYL, SULPHOCYANIDE OF. [MUSTARD, OIL OP.] 



ALLYLAMINE. [ORGANIC BASES.] 



ALLYLUREA. [UREA.] 



ALMACANTER, an Arabic term now disused, but which, with 

 many others, was formerly employed in astronomy. The name is 

 given to all the small circles parallel to the horizon ; so that two stars 

 which have the same almacanter, have the same altitude. Almacanter 

 would now be called a circle of altitude, in the same way as a small 

 circle parallel to the equator, all whose points have therefore the same 

 declination, is called a circle of declination. 



ALMAGEST, a name given by the Arabs to the /iryoATi aiiyra^a, 

 at gnat collection, the celebrated work of Ptolemy, the astronomer of 

 Alexandria. It was translated into Arabic about the year A.D. 827, 

 under the patronage of the Caliph Al Mamun, by the Jew Alhazen ben 

 Joseph, and the Christian Sergius. The word in the Arabic article nl 

 prefixed to the Greek word mtijuttu, 'greatest,' a name probably 

 derived from the title of the work iteelf, or, as we may judge from the 

 superlative adjective, partly from the estimation in which it was held. 



ALMANAC. The derivation of this word has given some trouble to 

 grammarians. The most rational derivation appears to us to be from 

 the two Arabic words al, the article, and mntia or manaji, ' to count.' 



An almanac, in the modern sense of the word, is an annual publi- 

 cation, giving the civil divisions of the year, the movcable and other 

 feasts, and the times of the various astronomical phenomena, including 

 in the latter term not only those which are remarkable, such as the 

 eclipses of the moon or sun, but also those of a more ordinary and 



useful character, such as the places of the sun, moon, and planets, the 

 petition of the priuci|ial fixed stars, the times of high and low water, 

 .-in. I Midi information relative to the weather as observation has hitherto 

 furnished. The agricultural, political, and statistical information which 

 is usually contained in popular almanacs, though as valuable a part of 

 the work as any, is comparatively of modern date. 



It is impossible that any country in which astronomy was at all 

 cultivated could be long without an almanac of some species. Accord- 

 ingly, we find the first astronomers of every age and country employed 

 either in their construction or improvement. The belief in astrology, 

 which has prevailed throughout the East from time immemorial, 

 rendered almanacs absolutely necessary, as the very foundation of the 

 pretended science consisted in an accurate knowledge of the state of 

 the heavens. With the almanacs if indeed they had them not before 

 the above-mentioned absurdities were introduced into the west, and 

 strange to say, it is only within tin- !a.-t twenty years that astrological 

 predictions have not been contained in nine almanacs out of ten. It is 

 not known what were the first almanacs published in Europe. That 

 the Alexandrian Greeks constructed them in or after the time of 

 Ptolenueus, appears from an account of Theon, the celebrated commen- 

 tator upon the Almagest, in a manuscript found by M. Delambre at 

 Paris, in which the method of arranging them is explained, anil the 

 proper materials pointed out. It is impossible to suppose that at any 

 period almanacs were uncommon ; but in the dearth of books whose 

 names have come down to us, the earliest of which Lalande, an inde- 

 fatigable bibliographer, could obtain any notice, are those of Solomon 

 Jarchus, published in and about 1150, and of the celebrated Pnrlwich, 

 published 1450-61. The almanacs of Regiomontanus, said by Railly, 

 in his ' History of Astronomy,' to have been the first ever published, 

 but which it might be more correct to say ever printed, appeared 

 between 1475 and 1506, since which time we can trace a continued 

 chain of such productions, of which our limits will not allow us to 

 give even the names of the authors. They may be found in the 

 ' Bibliographic Astronomique ' of Lalande, and in Button's ' Mathe- 

 matical Dictionary,' article 'Ephemeris.' The almanacs of Regiomon- 

 tanus, which simply contained the eclipses and the places of the 

 planets, were sold, it is said, for ten crowns of gold. An almanac for 

 1442, in manuscript we presume, is preserved in the ' BibliothcH 

 Hoi,' at Paris. The almanacs of Engel, of Vienna, were publishc* i 

 1494 to 1500 ; and those of Bernard do Granolachs, of Barcelona, from 

 about 1487. There are various manuscript almanacs of the 14th 

 century in the libraries of the British Museum, and of Corpus Christ! 

 College, Cambridge. 



The first astronomical almanacs published in France were those of 

 Duret de Montbrison, in 1637, which series continued till 1700. But 

 there must have been previous publications of some similar description ; 

 for, in 1579, an ordonnance of Henry III. forbade all makers of alma- 

 nacs to prophesy, directly or indirectly, concerning the affairs either of 

 the state or of individuals. In England the royal authority was less 

 rationally employed. James I. granted a monopoly of the trade in 

 almanacs to the universities and the Stationers' Company. The uni- 

 versities however were only passive, having accepted an annuity from 

 their colleagues, and resigned any active exercise of their privilege. 



In 1775 a blow was struck which demolished the legal mono] .Iy. 

 One Thomas Carnan, a bookseller, whose name deserves honourable 

 remembrance, had some years before detected or presumed the ille- 

 gality of the exclusive right, and invaded it accordingly. The cause 

 came before the Court of Common Pleas in the year above mentioned, 

 and was there decided against the Company. Lord North, in 1779, 

 brought a bill into the House of Commons to renew and legalise the 

 privilege, but, after an able argument by Erskinc in favour of tin- 

 public, the House rejected the ministerial project by a majority of 

 forty-five. The defeated monopolists managed to regain the exclusive 

 market, by purchasing the works of their competitors. The astrological 

 and other predictions still continued ; but it is some extenuation that 

 the public, long used to predictions of the deaths of princes and fall* of 

 rain, refused to receive any almanacs which did not contain their 

 favourite absurdities. It in said (Baily, ' Further Remarks on flu- 

 Defective State of the Nautical Almanac,' &c., p. 9) that the Sta: 

 Com]>any once tried the ox]H-riinent of initially reconciling I 

 Moore and common sense, by no greater step than omitting the column 

 of the mnon'H influence on the |>art* of the human body, and that most 

 of the copies were returned upon their hands. 



The ' British Almanac' was published by the Society for the Diffusion 

 of Useful Knowledge in 1828. Its success inducted the St.v 

 Company to believe that the public would no longer refuse n good 

 almanac because it only predicted purely astronomical phenomena, and 

 they accordingly published the ' Englishman's Almanac.' We may also 

 ailif tint other almanacs have diminished the quantity and tone of their 

 objectionable parts. But astrology still puts forth a timid voice in the 

 name of Francis Moore ; and there are professedly astrological almanacs, 

 which have their purchasers, and probably their believers. 



Of the professedly astronomical almanacs, the most important in 

 England is the ' Nautical Almanac,' published by the Admiralty, for 

 the use both of astronomers and seamen. This work was projected by 

 Dr. Maskelync, then Astronomer Royal, and first iipjworud in 1767. 

 The employment of lunar distances in finding the longitude, of the 

 efficacy of which method Maskelyne had satisfied himself in a voyage 



