EPODE EQUATION. 



77 



and particulars of their cycles, which afford striking 

 coincidences with those of the Tartars, Japanese, &c. 

 We shall only add, that their first cycle began in the 

 11:0111 h of January, A.D. 1090. 



List of the Correspondence of Eras trith the year 1835. 



[When the commencement of the year coincides with the Christian year, 

 that alone will be given ; when it begins at a different season, the month 

 in which the 1st of January, 1835, occurs will be also stated.] 



Arrangement Correspond 



inptecrding ence with 



Article. 1835. 



1 Roman year. 25S8 



2 Olympiads 7th month 6th year of 6.Y2 



3 Year of the world . . (Constantinopolitan acct.) 7343 



4 (Alexandrian account) 7327 



5 (Abyssinian acct.) 24th Tahsas 7327 



6 (Jewish account) 7th Thebet 5595 



7 Era of Nabonassar 8th month of 1583 



8 Egyptian 24th Cohiac 2581 



9 Julian period 6548 



10 Diocletian, or of Martyrs 34th Cohiac 1551 



11 Seleucides, or Grecian Audymeus 2146 



12 Death of Alexander 3d month 2153 



4th month 1959 

 ct.) Audymcus 1883 



(Syrian acct.) Camm. II. 



4th month b850 



1873 



. . .(Parseeacct.)i 120 3 

 4th or 5th month 5 



1284 



Abbreviations. 



A. U. C. 



Olymp. 

 A. M. Const. 

 A. M. Alex. 

 A. M. Abyss. 

 A. M. 

 JEr. Nab. 

 A. JEg. 

 Jul Per. 

 JEr. Diocl. 

 Mr. Seleuc. 

 A. Mort. Alex. 

 JEr. Tyr. 

 Ca;s. Ant. 



A. Pers. 

 An. Arm. 



Samvat. 



Beng. Sen. 



Fusl. 



Fusl. 



Paras. 



Grab. 



Cyc. Brin. 



15 



16 Era of Abraham. 



17 Spanish, or of the Ctesars 



18 Persian era of Yezdegiid III 



19 Armenian common year 29th Drethari 



20 ecclesiastical year lath Kagoths 1283 



21 Hegira 7th Regeb 1250 



22 Caliyug Poos or Margaly 49.36 



23 Salivahana (Saca) 1757 



24 Vicramaditaya (Samvat) 1891 



25 Bengalee 1241 



i Fuslee (Bengal account) 1*42 



27 (Telinga account) 1244 



28 Parasurama 4th month of 1010 



29 Grahaparivrithi 59th year of 21st cycle 



30 Brihuspotee (Bengal) 40th year of 84th cycle 



31 (Telinga) 2'Jth year of 83d cycle 



32 Chinese year ?4th cycle 



EPODE (Latin epodos, from the Greek l-ru^as, from 

 / and attiu, I sing) ; the last division in the choral 

 song of the ancients, which was sung when the chorus, 

 after the strophe and antistrophe, had returned to its 

 place (see Chorus) ; so that it was a kind of closing 

 song, or finale. Tliis epode had a peculiar measure, 

 and an arbitrary number of verses. By the term 

 epode is also understood a sort of satirical ode ; 

 according to Hephaestion, one which has longer and 

 shorter iambic verses, following each other alter- 

 nately. This name is also given to the 'fifth book of 

 the odes of Horace. All the odes in this book, how- 

 ever, are not satirical, and Scaliger therefore sup- 

 poses, that the name here signifies an appendix to 

 the odes : the epodes 'having been joined to the other 

 works of the poet after his death. 



EPOPEE. See Epic. 



EPOPT^E (from the Greek i-J and S# T ofuu,I see) ; 

 inspectors, or spectators, i. e., initiated; a name 

 given to those who were admitted to view the secrets 

 of the greater mysteries, or religious ceremonies of 

 the ancient Greeks. 



EPPING, a town in Essex, situated seventeen 

 miles from London, on the road to Newmarket, and 

 in the midst of a forest to which it gives name. 

 Population of town and parish in 1831, 2313. 



EPROUVETTE ; the name of an instrument for 

 ascertaining the strength of fired gunpowder, or of 

 comparing the strength of different kinds of gun- 

 powder. One of the best, for the proof of powder in 

 artillery, is that contrived by doctor Hutton. It 

 consists of a small brass gun, about 2 feet long, 

 suspended by a metallic stem, or rod, turning by an 

 axis, on a firm and strong frame, by means of which 

 the piece oscillates, in a circular arch. A little 

 below the axis, the stem divides into two branches, 

 reaching down to the gun, to which the lower ends 

 of the branches are fixed, the one near the muzzle, 

 the other near the breech of the piece. The upper 

 end of the stem is firmly attached to the axis, which 

 turns very freely by its extremities in the sockets of 

 the supporting frame, by which means the gun and 

 Btem vibrate together in a vertical plane, with a very 



small degree of friction. The piece is charged with 

 a small quantity of powder (usually about two ounces) 

 without any ball, and then fired ; by the force of the 

 explosion, the piece is made to recoil or vibrate, 

 describing an arch or angle, which will be greater or 

 less according to the quantity or strengUi of the 

 powder. 



EPSOM; a place in England, fourteen miles south of 

 London, in Surrey, celebrated for its medicinal springs, 

 of a purgative quality, discovered in 1618, and for 

 the downs, on which horse-races annually take place. 

 Near it Henry VIII. built a splendid palace, called 

 Nonsuch. Population of parish in 1831, 3231. 



EPSOM SALT (sulphate of magnesia, cathartic 

 salt) appears in capillary fibres or acicular crystals ; 

 sometimes presents minute prismatic crystals. The 

 fibres are sometimes collected into masses; and it 

 also occurs in a loose, mealy powder : its colour, 

 white, grayish, or yellowish : it is transparent, or 

 translucent, with a saltish, bitter taste. It is soluble 

 in its own weight of cold water, and effloresces on 

 exposure to the air. It is composed of water, sulphu- 

 ric acid and magnesia. It is found covering the 

 crevices of rocks, in caverns, old pits, &c., in the 

 vicinity of Jena, on the Harz, in Bohemia, &c., in 

 mineral springs, in several lakes in Asia, and in sea- 

 water. It is obtained for use from these sources, or 

 by artificial processes, and is employed in medicine 

 as a purgative. The English name is derived 

 from the circumstance of its having been first pro- 

 cured from the mineral waters at Epsom. See 

 Magnesia. 



EQUATION, in algebra, is the expression of the 

 equality of different indications of the same magni- 

 tude; as, for instance, 9 and 2 are equal to 11, in 

 mathematical characters is expressed thus: 9+2= 

 11 ; or, 3 from 4 leave 1, is 4 3=1. An equation 

 may contain known quantities and unknown quan- 

 tities. The latter are usually indicated by the last 

 letters of the alphabet ; and it is one of the main 

 objects of mathematics to reduce all questions to 

 equations, and to find the value of the unknown 

 quantities by the known, which is sometimes a 

 difficult, but, at the same time, interesting operation ; 

 because x, or the unknown quantity, may be given 

 under so involved a form as to require the greatest 

 tact to determine its value. 



When a problem is proposed for solution, the first 

 thing to be done, is to express the condition- of all the 

 quantities known and unknown in algebraical lan- 

 guage. The next step is to obtain a distinct equation 

 tor each of the unknown quantities. The terms of an 

 equation are frequently in the form of powers and 

 roots, the unknown quantity being sometimes a square, 

 cube, biquadrate, &c., and thus equations are distin- 

 guished into degrees. Thus x 2 b c is an 

 equation of the first degree ; however the unknown 

 quantity x is not involved ; x 1 = 13 + 9 is an equation 

 of the second degree, the unknown quantity x being 

 involved to the second power, &c. Equations are also 

 either pure or adfected. They are pure when the 

 unknown quantity occurs only in one power, as X s 

 = 47 + 18 or x 4 = 19 + b ; but they are said to be 

 adfected when the unknown quantity occurs in differ- 

 ent powers, as * + 2 a? = 15 2 a, or x* + 2 x 3 + 

 of + 5# = 19 + 143. The great object of Algebra 

 is to enable us to simplify the structure of an equa- 

 tion without altering the value of any of its quanti- 

 ties, until we arrive at the most simple form, where 

 the unknown quantity stands at one side of the equa- 

 tion alone, and uninvolved, and its value at the other 

 side. 



EQUATION in Astronomy ; any quantity to be added 

 to, or subtracted from, the mean motion of auy 

 heavenly body, in order to determine its true place 



