ORA. 



ORACLE. 



_ this intersection the two lines appear to diverge from one 

 another, and to become indistinct. The point of intersection is that 

 at which a minute object being placed, its image would be distinctly 

 seen by the eye at the aperture, and its distance from the eye may be 

 imiminiXmly found by means of a scale of inches on the instrument, a 

 sliding index being, at the time of in^lri"c the observation, moved to 

 the point of intersection. 



This distance affords, evidently, a measure of the refractive power 

 of the observer's eye ; since rays of light diverging from a small object 

 at that -ii'tan"* are, by the lenses of the organ, made to converge 

 accurately to a point on the retina, so as to form there a single and 

 well <Wr* fl image. If the object were either brought nearer to or 

 removed farther from the eye, the rays, after passing through the two 

 apertures, would form two images, both of which would appear to be 

 IMS' perfectly defined than the single image. 



It being assumed that a person whose sight is perfect sees a small 

 object distinctly at the distance of 8 inches from the eye, Dr. Young 

 obtained by computation a series of numbers which he placed on the 

 scale of the optometer, at such distances from the plate containing the 

 apertures, that a spectator having a prabyopic eye (or one which, like 

 those of most persons who are advanced in life, has distinct vision of 

 fre.ll objects only when they are at greater distances than 8 inches) 

 on looking through the slits and observing the place where the two 

 images of the line cross each other, might ascertain at once, by the 

 number at the place, the focal length of a convex lens which would 

 enable him to see distinctly at 8 inches. He also computed a series of 

 numbers which he placed on the scale in such situations that a person 

 having a wyo/>i'c eye, or one which has distinct vision of objects at less 

 fofn that distance from it, on observing the place at which the lines 

 appeared to intersect one another, might ascertain the virtual focus of a 

 concave lens which would enable him to see distinctly at 8 inches. The 

 optometer thus became a means of enabling persons to make choice of 

 the proper lenses for spectacles which would correct the imperfections 

 of their natural vision. 



But the scale of Dr. Young's optometer being, for convenience, only 

 8 inches long, and the inferior limit of distinct vision in a presbyopic 

 eye being beyond that distance, Dr. Young applied to his instrument a 

 convex lens of 4 inches focus, by which the point of distinct vision for 

 such an eye was reduced within 8 inches from it : the numbers on his 

 scale were therefore computed for the instrument when furnished with 

 such a lens. 



Dr. Young used the optometer for the purpose of determining the 

 refractive powers of the eye, not only in its usual state, but also when, 

 in renri of cataract, the crystalline lens had been displaced or extracted, 

 and when the effect of the cornea had been rendered null by immersing 

 the anterior part of the eye in water, which was contained in a cell of 

 a proper form, and having a plane glass in front. By such means he 

 endeavoured to ascertain in what manner the eye accommodates 

 itself to distinct vision for objects at different distances from it; and 

 his conclusion is that the faculty depends entirely upon changes of 

 figure which take place in the crystalline lens. (Lecturea on Natural 

 Philiaophy, vol. ii.) 

 ORA. [MONEY.] 



ORACLE (from the Latin orarulunt, and that from 01, or-lt, a 

 mouth). Oracle was the Roman name used to denote the place where 

 answers were supposed to be given by any of the divinities to those 

 who consulted them respecting the future. Sometimes also it was 

 used to signify the response which was delivered, and sometimes the 

 deity from whom this response was imagined to proceed. Its primary 

 and proper signification indeed is that of a response. Cicero (' Topic.,' 

 20) says that oracula were so called " quod iuest in his Deorum Oratio." 

 Those who were sent to consult them were sometimes called oratora. 

 (Livy, v. 16.) Oracular responses were called chrami (x/)o>o() or 

 man'uia (/uurfia) by the Greeks ; the name mantriim (luanttor) was 

 also often given to the oracular place, or the seat of the oracle. 



Curiosity regarding futurity, and the desire to penetrate its mys- 

 teries, are dispositions which exert a powerful control over the minds 

 of men in every stage of society ; among nations that have made little 

 advancement in civilisation and intelligence, they operate with peculiar 

 force | and in these dispositions, combined with the belief that the 

 gods had both the ability and the inclination to afford the knowledge 

 so eagerly longed after, the oracles of the pagan world had their origin. 

 Of these oracles the most famous were those of Greece, and among 

 them that which had claims to the highest antiquity was the oracle of 

 Zeus at Dodona [DODONA, in GEOO. Div.] But the most celebrated 

 of the Grecian oracle* was that of Apollo, at Delphi, a city built on 

 the slopes of Parnassus in Phocis. [DELPHI, in GEOO. Div.j Besides 

 the oraclee of Zeus and Apollo at Dodona and Delphi, that of 

 Trophonius, near Lebadeia in Boeotia, may be mentioned, as having 

 been held in high estimation. There were many other oracles in 

 Greece, but of lee* repute. 



Among the other most noted oracles of antiquity were that of 

 Zeus Ainmon in ton desert of Libya, that of the Branclndx in 

 Ionia, of Pella in Macedonia, of Sinope in Paphlagonia, of the head of 

 Orpheus at Lesbos, Ac. Most of the heathen deities, and even the 

 dcmigodi and heroes, had oracle* of their own. There were also 

 current in Greece numerous so-called prophecies, the production* of 

 individuals who were probably supposed to speak under a divine 



influence. Such were those of Bacia mad Museus, in which the battle 

 of Salami* was predicted, and that of Lysistratun, an Athenian. 

 (UenxL, viii. 96.) But those productions are perhaps more appro- 

 priately considered under the head of PROPHECY, though Herodotus 

 applies to them the same name (xpw*n) a* to the responses from 

 Delphi and other oracular places. As to the Sibylline oracles, see 



ton. 



Though the Romans had various modes of ascertaining the will 

 of the deities, it does not appear that oracles like those of Delphi or 

 Dodona were ever established among them ; and we find that the 

 oraclee of Greece, and particularly the far-famed oracle of Del]. hi. 

 were consulted by them on many important occasion*. (Livy, v. 15 ; 

 xxii. 57, Ac.) 



Among the Jews, the Urim and Thuinniim, which by an extra- 

 ordinary brightness made known the will of Jehovah, bore a striking 

 resemblance to the heathen oracles; and the oracle of Bathool, or 

 daui/htcr of At voice, which was originated after the death of Malachi, 

 was completely identical with them. 



The modes in which oracular response* were delivered were very 

 various. At Dodona they issued from the hollow of an oak ; at Delphi 

 they were delivered by the Pythia ; and at the oracle of Ammon they 

 were pronounced by the priests. At Memphis a favourable or unfavour- 

 able answer was understood to be returned, according as Apis received 

 or rejected what was presented to him. [Ans.] Sometimes the reply 

 was given by letter ; and sometimes the required information could be 

 obtained only by casting lots the lots being dice with certain characters 

 engraved on them, the meaning of which was ascertained by referring 

 to an explanatory table. Dreams, visions, and preternatural, voices 

 also announced the will of the divinities. 



The importance attached by the Greeks and Romans to oracular 

 responses is a striking feature in the history of those people. Hardly 

 any enterprise, whether public or private, of any moment, was under- 

 taken without recourse being had to them and their sanction being 

 obtained. In later times, indeed, their influence was greatly dimi- 

 nished, and thus gradually fell into disrepute. Cicero affirms that 

 long before his age even the Delphic oracle was regarded by many 

 with contempt ; and there is little doubt that oracles were considered 

 by philosophers as nothing different from what they really were, and 

 by politicians as instruments which could be used for their purpose*. 

 The reply of Cato to Labienus, who wished him after the battle of 

 Pharsalia to consult the oracle of Jupiter Ammon, embodies the 

 opinion of that eminent Stoic respecting the propriety of thus ques- 

 tioning the gods. " On what account, Labienus, would you have me 

 consult Jupiter? Should I ask him whether it would be better to 

 lose life than liberty t Whether life be a real good ? We have wit Uin 

 us, Labienus, an oracle that can answer all these questions. Nothing 

 happens but by the order of God. Let us not require of him to repeat 

 to us what he has sufficiently engraved on our hearts. Truth has not 

 withdrawn into these deserts ; it is not engraven on the sands of 

 Libya. .... Let the inconstant and those that are subject to wnver 

 according to events have recourse to oracles. For my part, I find in 

 nature everything that can inspire the most constant resolution. The 

 coward, as well as the brave, cannot escape death. Jupiter can tell us 

 no more." (Lucan, ' Pharsalia,' lib. ix., v. 566-584.) 



The question has been gravely discussed, whether oracular responses 

 ought to be ascribed to mere human ingenuity and wisdom, or to 

 diabolical agency. Most of the Christian fathers maintained that they 

 ought to be ascribed to the latter. Allusion is made to this opinion 

 in the first book of ' Paradise Lout/ where the spirits of Pandemonium 

 are described as having taken possession of the various idols of the 

 heathen world. There is nothing, however, in the history of the ancient 

 oracles to countenance such a notion, or to lead to the belief that 

 a supernatural cunning and skill directed them. Their replies to 

 those who consulted them were for the most part obscurely and 

 equivocally expressed, and so as to admit of different explanations, 

 according as the wishes of the inquirer might suggest or the e\ent. 

 determine; and even in those instances where trial was designedly 

 made of the reality of their pretensions, it is not difficult to account 

 for the success with which they stood the test, without calling in the 

 assistance of demoniacal instrumentality. 



Another circumstance respecting the oracles, which has given birth 

 to much controversy, is, the time when they ceased altogether to give 

 responses. Eusebius was the first who propounded the opinion that 

 they became silent ever after the birth of Christ, and many writers, 

 willing thus to do honour to the author of Christianity, have given it 

 their support. Milton makes allusion to this theory also in the most 

 magnificent of all his minor poems, ' The Hymn of the Nativity ; ' and 

 in lines of solemn and elevated beauty, of which the following are the 

 commencement, pictures the consternation of the heathen idols at the 

 advent of the Saviour : 



"The oracles are dumb, 

 No voice or hideous hum 



Kings through the arched roof in words deceiving, 

 Apollo from his shrino 

 Can no more divine, 



With hollow shriek the steep of Delphos leaving. 

 No nightly trsnce or breathed spell 

 Inspires the pale-eyed priest from the prophetic cell." 



