

APRIL 





. 



The connexion of the arithmtioal rufcs, in which 

 figure* in nooasaiwh found, with the preceding, will not at one* be 

 obrioui ; but our limit* oblige in to refer to I \XD Kvon 



T105 oo this point Newton fint spoiled the theory of derived 

 functions directly to algebraical equations; nd the method wu 

 further extended by Lagrange. 



A I 'HI I., the fourth month of the year, consisU of thirty days, which 

 was the number mid to be Magnet! to it by Romulus. Numa Pom- 

 pilius deprived it of one <Ujr, which Julius Cswar reetored, and which 

 it ha* CTBT sine* retained. In the original Alban or Latin Calendar, 

 April held the fint station, and then consisted of thirty six days. 

 {Prtisd, ' Lexicon Antiq. Roman.' torn, i. p. 129 ; Brady's CUvis 

 Caleodaria,' p. 67.) Its name u usually considered to hare been 

 derived from o/wrirr, to open ; either from the opening of the buds, or 

 of the bosom of the earth in producing vegetation. The Anglo-Saxons 

 called it Ooster or Easter-Monath. In thin month the sun travels 

 through parts of the signs of Aries and Taurus, that is to say, of thoee 

 parts of the ecliptic which astronomers designate by those names. The 

 real motion of the sun among the constellations is through parts of 

 Puces and Aries. [PR KCESSIOX; ZODIAC.] 



APRIL CEREMONIES. The custom of making fools on the first of 

 April U a practice well known in England, France, Sweden, and probably 

 in other countries of Europe ; and it is believed to be connected 

 with an immemorial custom among the Hindoos, held near the same 

 period in India, towards the end of March, colled the Huli Festival, 

 when mirth and festivity reign among the Hindoos of every class, and 

 people are sent upon errands and expeditions which end in disappoint- 

 ment, and raise a laugh at the expense of the person sent. (' Asiat. Res.' 

 vol. ii. p. 334. * In Europe the practice is similar : the fun consists in 

 deceiving a person in any not injurious manner, such as " sending them 

 on a sleeveless errand," as Addiaon terms it in the ' Spectator.' 



The origin of this April custom seems unknown everywhere, though 

 Bellingen, in his ' Etymology of French Proverbs,' considers that it 

 may possibly have an allusion to the mockery of our Saviour, about 

 this time, by the Jews : a conjecture which U in some degree paralleled, 

 if not corroborated, by the custom of Lifting in the Easter holidays, 

 undoubtedly intended to represent our Saviour's resurrection. 



In England, the first of April is usually termed ' All Fools' Day,' 

 and the person imposed upon, an April Fool. In France this person 

 is called a ' Poiason d'A ml,' i.e., A mackerel, or silly fish. In S. 

 ' an April Gowk.' In Portugal, according to Southey, the like practice 

 prevails on the Sunday and Monday preceding Lent Maurice, ' Indian 

 Antiq.' vol. vi, p. 71, speaks of the Huli Festival as the celebration of 

 the period of the vernal equinox. 



A PRIOTU and A POSTERIO'RI ; two logical terms, signifying, 

 literally, ' from a thing before,' and ' from a thing after.' They are 

 applied to distinguish between two different methods of reasoning ; the 

 first, a priori, in which the conclusion is drawn from previous argu- 

 ment*, which render it unnecessary to examine the particulars of the 

 ease in point ; the second, a pnttrrinri, in which the thing to be proved 

 is 'examined, and made the source out of which the reasoning is drawn. 

 It must be noticed, however, that these are rather terms of common 

 conversation and writing, than of logic, properly so called ; so that 

 they are seldom noticed by writers on that science. The use of them 

 i in general very vague, and the consequence of any attempt to define 

 them very strictly would be either to make out a priori reasoning to 

 be altogether impossible, or to throw insuperable difficulties in the way 

 of finding where it ends and the other begins. In common language, 

 we reason a priori when we infer the existence of a Ood from the 

 general difficulties in the supposition of the existence of what we then 

 call the creation, on any other hypothesis; but we reason a. potterim 

 when we inf. r the same from marks of intelligent contrivance in this 

 particular creation with which we are acquainted. 



The term a priori is, however, frequently used in a sense which 

 implies " previous to any special examination." As when a sentence 

 bfffaM who " a priori we should think." &c 4c., which in most cam 

 will be found to mean nothing more than an expression of the leaning 

 which UM speaker found his mind inclined to, when bo had only heard" 

 the proposition, and before he had investigated it 



All a priori reasoning is dubious, to say the least : in but very few 

 cases, if any, an we able to say we know sufficient beforehand to render 

 this sort of argument safe. Pure mathematics and logic are capable of 

 establishment a priori, and no other sciences whatever. But though 

 the method if of little fleet towards the establishment of most kinds 

 of troth, it is highly effective in its discovery ; indeed, by the very 

 nature of its definition, it must be the guide which points out the 

 probable direction in which the thing sought may be found. Columbus 

 **P* to look for the continent of America, in consequence of certain 

 eoavioticns of his own, derived from a priori reasoning. So far he was 

 right : but had he contented himself with writing a quarto volume to 

 proT th existence of the new continent, by reasons which were only 

 strong enough to maks it right to lx>k for more, some less imaginative 

 *"*< ""Si* """^ kve ten the real discoverer. 



APSE, or APSIS in Architecture, the semicircular termination to 



tfc, choir of a cathedral or church. Formerly it was applied to the 



entire eoafa^or a portion railed off. The apse corresponds to the hemi- 



:h was the tribunal in the ancient Roman 



Basilica; Hid hence in Roman Catholic countries the bishop's throne is 



always placed within the apse, the church being regarded as the 

 tribunal where the bishops sat to administer spiritual justice, penance 

 to the guilty, and the euohariat to the absolved. [BASILICA.] The 

 term apse is also applied to the semicircular terminations of aii-I 

 sftntrtimtn to similar terminations of transepts. In the cathedrals of 

 Italy, Germany, and France, the apaidal termination is very general. 

 In England, the cathedrals of Canterbury, Rochester, Norwich, and 

 Peterborough, Ripon Minster, and Westminster Abbey, as well as 

 several pariah churches, have apaidal terminations ; and in some 

 instances, as at Gloucester and Worcester cathedrals, the crypto retain 

 the apaidal form, though the apse itself baa been removed at a 

 subsequent to the original foundation of the church. In 

 cathedrals a great complexity of form is given to the apse by the 

 substitution of a range of columns for the semicircular wall, beyond 

 which is a series of chapels. For this form, Mr. Ferguason (' Handbook 

 of Architecture,' p. 618) proposes the vernacular term rhrrrl. Ho gays, 

 " The apse, properly speaking, is a solid semicylinder, surmounted by a 

 semfdome, but always solid below, though generally broken Iiv win- 

 dows above. The chertl, on the contrary, is an apse, always inclosed by 

 an open screen of columns on the ground-floor, and opening into an 

 aisle, which again always opens into three or more p- 

 This arrangement is so peculiarly Fri-m-li. that it may properly )* 

 characterised by the above French word, a name once commonly 

 applied to it, though latterly it has given way to the more classical but 

 certainly lea* suitable term of apse." But the term apse (abiiiin 

 generally applied to it by French architect* and writers on archi- 

 tecture. 



APSIDES, a Greek term, used to signify those points of a i 

 orbit in which it is moving at right angles to the line drawn to the 

 primary. These points are also those of greatest and least distance 

 from the primary. [APOOEK and PERIOEE for the moon and sun : 

 APHELION and PERIHKLION for the earth or a pi 



APTERAL, a term used in architecture with reference more par- 

 ticularly to n mode of arrangement peculiar to the temples of the 

 ancient Greeks ami H..in:ni-. It is formed from a (Jn-ek <-oiii|mii,l 

 term, signifying ' without wings ; ' and in this sense it is 

 temple having prostyles, or porticoes of columns project ini' in.in jti 

 fronts or ends, but of which the columns do not extend laterally, and 

 run along the flanks from one end to the other, so as to ni.ik.- it 

 peripteral. [TEMPLE.] Modern churches which have |orticoes, though 

 some of them are professedly on the Greek model, are, nevertheless, 

 generally, illustrations of the apteral arrangement, and of these that of 

 St. Pancras in London may be best referred to as an example. 



APUS (Constellation), from the Greek tatout, without feet, used to 

 signify the bird of Paradise, the Ant Indita of I.inn;eus. which was 

 formerly believed to have no feet. It is a constellation introduced by 

 Bayer, and lies too near the south pole to be visible in our hemi 

 It is surrounded by Octons, I'avo, Triangulum Australe, and Cameleon. 

 The following is a classified enumeration of its principal stars : 



JJaftnitudc. 

 4 



4-5 . 

 5- 



B'5 . 

 6 



Number of Stan. 



. 1 



. . 1 



. 1 



. . 1! 

 . 6 



n 



Hence the total number of stars visible to the naked eye in this con- 

 stellation amounts to 11. The principal star is thus designated : 



Character, 

 f 



No. In dialogue 



of Ijiriillf. 



L71C2 



No. In Ca'alojnio 



of DrlUih A ocilion. 



5810. 



Magnitude. 

 4 



AQUAFORTIS. [NiTRic Aero.] 



AQUA REGIA. [NITROHTDROCHLORIC Aero.] 



AQUA'RIUS (Constellation), the Water-Bearer, one of the twelve 

 zodiacal constellations. Its Greek name is "TSpoxotvs, the Water- Pourcr. 

 In the Indian zodiac it is simply a water-jug, the name of which, accord- 

 ing to Legentil, is Coumbam, and the same in the Arabic. In the 

 Egyptian, it is a male figure holding two urns, from which the water 

 flows. The mythology of the Greeks refers the Water-Bearer in 

 different places to the fables of Deucalion, Ganymede, Arisbeus, and 

 Cecrops. Its probable origin however, whether we place the origin of 

 the zodiac in India or Egypt, is the watery season of the year in which 

 the sun was in this sign. Dupuis, who supports the latter opinion, 

 thinks that Aquarius, as well as Capricornus and Pisces, refer to the 

 months of the year during which the inundation of the Kile took 

 place. Legentil, who advocates the farmer, imagines that they represent 

 the rainy season which is absolutely necessary for the growth of the 

 riot-crops. 



The constellation Aquarius may be found in the heavens by pro- 

 ducing southward a line drawn through the bright stars in the head of 

 Andromeda and the wing of Pegasus. This line passes through the 

 two brighter stars in Aquarius, a and 0, situated in th^ two shoulders. 

 The middle point between these two shoulder stars is on the meridian 

 at 12, 10, 8, and 8 P.M., in the months of August, September, October, 

 and November respectively, at an altitude of about 35 degrees. 



