two such points, opposite each other, at one of which the sun crosses the equator toward the north and at the other toward the south. They are called vernal and autumnal respectively, from the relation of the corresponding times to the seasons of the northern hemisphere. The line of the equinoxes is the imaginary diameter of the celestial sphere which joins them.
The vernal equinox is the initial point from which the right ascensions and the longitudes of the heavenly bodies are measured (see Astronomy: Spherical). It is affected by the motions of Precession and Nutation, of which the former has been known since the time of Hipparchus. The actual equinox is defined by first taking the conception of a fictitious point called the Mean Equinox, which moves at a nearly uniform rate, slow varying, however, from century to century. The true equinox then moves around the mean equinox in a period equal to that of the moon’s nodes. These two motions are defined with greater detail in the articles Precession of the Equinoxes and Nutation.
Equinoctial Gales.—At the time of the equinox it is commonly believed that strong gales may be expected. This popular idea has no foundation in fact, for continued observations have failed to show any unusual prevalence of gales at this season. In one case observations taken for fifty years show that during the five days from the 21st to the 25th of March and September, there were fewer gales and storms than during the preceding and succeeding five days.
EQUITES (“horsemen” or “knights,” from equus, “horse”),
in Roman history, originally a division of the army, but subsequently
a distinct political order, which under the empire
resumed its military character. According to the traditional
account, Romulus instituted a cavalry corps, consisting of three
centuriae (“hundreds”), called after the three tribes from
which they were taken (Ramnes, Tities, Luceres), divided into
ten turmae (“squadrons”) of thirty men each. The collective
name for the corps was celeres (“the swift,” or possibly from
κέλης, “a riding horse”); Livy, however, restricts the term to
a special body-guard of Romulus. The statements in ancient
authorities as to the changes in the number of the equites
during the regal period are very confusing; but it is regarded as
certain that Servius Tuillus found six centuries in existence, to
which he added twelve, making eighteen in all, a number which
remained unchanged throughout the republican period. A
proposal by M. Porcius Cato the elder to supplement the deficiency
in the cavalry by the creation of four additional centuries
was not adopted. The earlier centuries were called sex suffragia
(“the six votes”), and at first consisted exclusively of patricians,
while those of Servius Tullius were entirely or for the most part
plebeian. Until the reform of the comitia centuriata (probably
during the censorship of Gaius Flaminius in 220 B.C.; see
Comitia), the equites had voted first, but after that time this
privilege was transferred to one century selected by lot from the
centuries of the equites and the first class. The equites then
voted with the first class, the distinction between the sex suffragia
and the other centuries being abolished.
Although the equites were selected from the wealthiest citizens, service in the cavalry was so expensive that the state gave financial assistance. A sum of money (aes equestre) was given to each eques for the purchase of two horses (one for himself and one for his groom), and a further sum for their keep (aes hordearium); hence the name equites equo publico. In later times, pay was substituted for the aes hordearium, three times as much as that of the infantry. If competent, an eques could retain his horse and vote after the expiration of his ten years’ service, and (till 129 B.C.) even after entry into the senate.
As the demands upon the services of the cavalry increased, it was decided to supplement the regulars by the enrolment of wealthy citizens who kept horses of their own. The origin of these equites equo privato dates back, according to Livy (v. 7), to the siege of Veii, when a number of young men came forward and offered their services. According to Mommsen, although the institution was not intended to be permanent, in later times vacancies in the ranks were filled in this manner, with the result that service in the cavalry, with either a public or a private horse, became obligatory upon all Roman citizens possessed of a certain income. These equites equo privato had no vote in the centuries, received pay in place of the aes equestre, and did not form a distinct corps.
Thus, at a comparatively early period, three classes of equites may be distinguished: (a) The patrician equites equo publico of the sex suffragia; (b) the plebeian equites in the twelve remaining centuries; (c) the equites equo privato, both patrician and plebeian.
The equites were originally chosen by the curiae, then in succession by the kings, the consuls, and (after 443 B.C.) by the censors, by whom they were reviewed every five years in the Forum. Each eques, as his name was called out, passed before the censors, leading his horse. Those whose physique and character were satisfactory, and who had taken care of their horses and equipments, were bidden to lead their horse on (traducere equum), those who failed to pass the scrutiny were ordered to sell it, in token of their expulsion from the corps. This inspection (recognitio) must not be confounded with the full-dress procession (transvectio) on the 15th of July from the temple of Mars or Honos to the Capitol, instituted in 304 B.C. by the censor Q. Fabius Maximus Rullianus to commemorate the miraculous intervention of Castor and Pollux at the battle of Lake Regillus. Both inspection and procession were discontinued before the end of the republic, but revived and in a manner combined by Augustus.
In theory, the twelve plebeian centuries were open to all freeborn youths of the age of seventeen, although in practice preference was given to the members of the older families. Other requirements were sound health, high moral character and an honourable calling. At the beginning of the republican period, senators were included in the equestrian centuries. The only definite information as to the amount of fortune necessary refers to later republican and early imperial times, when it is known to have been 400,000 sesterces (about £3500 to £4000). The insignia of the equites were, at first, distinctly military—such as the purple-edged, short military cloak (trabea) and decorations for service in the field.
With the extension of the Roman dominions, the equites lost their military character. Prolonged service abroad possessed little attraction for the pick of the Roman youth, and recruiting for the cavalry from the equestrian centuries was discontinued. The equites remained at home, or only went out as members of the general’s staff, their places being taken by the equites equo privato, the cavalry of the allies and the most skilled horsemen of the subject populations. The first gradually disappeared, and Roman citizens were rarely found in the ranks of the effective cavalry. In these circumstances there grew up in Rome a class of wealthy men, whose sole occupation it was to amass large fortunes by speculation, and who found a most lucrative field of enterprise in state contracts and the farming of the public revenues. These tax-farmers (see Publicani) were already in existence at the time of the Second Punic War; and their numbers and influence increased as the various provinces were added to the Roman dominions. The change of the equites into a body of financiers was further materially promoted (a) by the lex Claudia (218 B.C.), which prohibited senators from engaging in commercial pursuits, especially if (as seems probable) it included public contracts (cf. Flaminius, Gaius); (b) by the enactment in the time of Gaius Gracchus excluding members of the senate from the equestrian centuries. These two measures definitely marked off the aristocracy of birth from the aristocracy of wealth—the landed proprietor from the capitalist. The term equites, originally confined to the purely military equestrian centuries of Servius Tullius, now came to be applied to all who possessed the property qualification of 400,000 sesterces.
As the equites practically monopolized the farming of the taxes, they came to be regarded as identical with the publicani, not, as Pliny remarks, because any particular rank was necessary to obtain the farming of the taxes, but because such occupation was beyond the reach of all except those who were possessed of considerable means. Thus, at the time of the Gracchi, these
