[1] The coefficients were selected so that the roots might be nearly
1, 2, 3.
[2] The third edition (1826) is a reproduction of that of 1808; the
first edition has the date 1798, but a large part of the contents is
taken from memoirs of 1767-1768 and 1770-1771.
[3] The earlier demonstrations by Euler, Lagrange, &c, relate to the
case of a numerical equation with real coefficients; and they consist
in showing that such equation has always a real quadratic divisor,
furnishing two roots, which are either real or else conjugate
imaginaries [alpha] + [beta]i (see Lagrange's _Equations
numeriques_).
[4] The square root of [alpha] + [beta]i can be determined by the
extraction of square roots of positive real numbers, without the
trigonometrical tables.
EQUATION OF THE CENTRE, in astronomy, the angular distance, measured
around the centre of motion, by which a planet moving in an ellipse
deviates from the mean position which it would occupy if it moved
uniformly. Its amount is the correction which must be applied positively
or negatively to the mean anomaly in order to obtain the true anomaly.
It arises from the ellipticity of the orbit, is zero at pericentre and
apocentre, and reaches its greatest amount nearly midway between these
points. (See ANOMALY and ORBIT.)
EQUATION OF TIME, the difference between apparent time, determined by
the meridian passage of the real sun, and mean time, determined by the
passage of the mean sun. It goes through a double period in the course
of a year. Its amount varies a fraction of a minute for the same date,
from year to year and from one longitude to another, on the same day.
The following table shows an average value for any date and for the
Greenwich meridian for a number of years, from which the actual value
will seldom deviate more than 20 seconds until after 1950. The + sign
indicates that the real sun reaches the meridian _after_ mean noon; the
- sign _before_ mean noon.
_Table of the Equation of Time._
m. s. m. s. m. s.
Jan. 1 +3 26 Mar. 1 +12 39 May 1 -2 55
6 5 45 6 11 35 6 -3 27
11 7 51 11 10 20 11 -3 46
16 9 43 16 8 58 16 -3 51
21 11 19 21 7 30 21 -3 40
26 12 36 26 5 59 26 -3 16
Feb. 1 +13 42 Apr. 1 +4 9 June 1 -2 32
6 14 14 6 2 40 6 -1 44
11 14 25 11 +1 15 11 -0 48
16 14 17 16 -0 3 16 +0 14
21 13 52 21 -1 12 21 1 19
26 13 11 26 -2 10 26 2 24
July 1 +3 26 Sept. 1 +0 9 Nov. 1 -16 18
6 4 21 6 -1 28 6 -16 19
11 5 8 11 -3 10 11 -15 58
16 5 44 16 -4 55 16 -15 15
21 6 8 21 -6 41 21 -14 12
26 6 18 26 -8 25 26 -12 49
Aug. 1 +6 10 Oct. 1 -10 5 Dec. 1 -11 7
6 5 47 6 -11 38 6 - 9 9
11 5 9 11 -13 2 11 - 6 57
16 4 17 16 -14 14 16 - 4 35
21 3 12 21 -15 11 21 - 2 7
26 1 55 26 -15 52 26 + 0 23
EQUATOR (Late Lat. _aequator_, from _aequare_, to make equal), in
geography, that great circle of the earth, equidistant from the two
poles, which divides the northern from the southern hemisphere and lies
in a plane perpendicular to the axis of the earth; this is termed the
"geographical" or "terrestrial equator." In astronomy, the "celestial
equator" is the name given to the great circle in which the plane of the
terrestrial equator intersects the celestial sphere; it is consequently
equidistant from the celestial poles. The "magnetic equator" is an
imaginary line encircling the earth, along which the vertical component
of the earth's magnetic force is zero; it nearly coincides with the
terrestrial equator.
EQUERRY (from the Fr. _ecurie_, a stable, through its older form
_escurie_, from the Med. Lat. _scuria_, a word of Teutonic origin for a
stable or shed, cf. Ger. _Scheuer_; the modern spelling has confused the
word with the Lat. _equus_, a horse), a contracted form of "gentleman of
the equerry," an officer in charge of the stables of a royal household.
At the British court, equerries are officers attached to the department
of the master of the horse, the first of whom is called chief equerry
(see HOUSEHOLD, ROYAL).
EQUIDAE, the family of perissodactyle ungulate mammals typified by the
horse (_Equus caballus_); see HORSE. According to the older
classification this family was taken to include only the forms with
tall-crowned teeth, more or less closely allied to the typical genus
_Equus_. There is, however, such an almost complete graduation from the
former to earlier and more primitive mammals with short-crowned
cheek-teeth, at one time included in the family _Lophiodontidae_ (see
PERISSODACTYLA), that it has now become a very general practice to
include the whole "phylum" in the family _Equidae_. The _Equidae_, in
this extended sense, together with the extinct _Palaeotheriidae_, are
indeed now regarded as forming one of four main groups into which the
Perissodactyla are divided, the other groups being the Tapiroidea,
Rhinocerotoidea and Titanotheriide. For the horse-group the name
Hippoidea is employed. All four groups were closely connected in the
Lower Eocene, so that exact definition is almost impossible.
In the Hippoidea there is generally the full series of 44 teeth, but the
first premolar is often deciduous or wanting in the lower or in both
jaws. The incisors are chisel-shaped, and the canines tend to become
isolated so as in the now specialized forms to occupy nearly the middle
of a longer or shorter gap between the incisors and premolars. In the
upper molars the two outer columns of the primitive tubercular molar
coalesce to form an outer wall, from which proceed two crescentic
transverse crests; the connexion between the crests and the wall being
imperfect or slight, and the crests themselves sometimes tubercular.
Each of the lower molars carries two crescentic ridges. The number of
toes ranges from four to one in the fore-foot, and from three to one in
the hind-foot. The paroccipital, postglenoid and post-tympanic processes
of the skull are large, and the latter always distinct. Normally there
are no traces of horn-cores. The calcaneum lacks the facet for the
fibula found in the Titanotheroidea.
In the earlier _Equidae_ the teeth were short-crowned, with the
premolars simpler than the molars; but there is a gradual tendency to an
increase in the height of the crowns of the teeth, accompanied by
increasing complexity of structure and the filling up of the hollows
with cement. Similarly the gap on each side of the canine tooth in each
jaw continues to increase in length; while in all the later forms the
orbit is surrounded by a ring of bone. A third modification is the
increasing length of limb (as well as in general bodily size),
accompanied by a gradual reduction in the number of toes from three or
four to one.
[Illustration: FIG. 1.--a, Side view of second upper molar tooth of
_Anchitherium_ (brachyodont form); b, corresponding tooth of horse
(hypsidont form).]
All the existing members of the family, such as the domesticated horse
(_Equus caballus_) and its wild or half-wild relatives, the asses and
the zebras, are included in the typical genus. In all these the crowns
of the cheek-teeth are very tall (fig. 1, b) and only develop roots late
in life; while their grinding-surfaces (fig. 2, b and c) are very
complicated and have all the hollows filled with cement. The summits of
the incisors are infolded, producing, when partially worn, the "mark."
In the skull the orbit is surrounded by bone, and there is no distinct
depression in front of the same. Each limb terminates in one large toe;
the lateral digits being represented by the splint-bones, corresponding
to the lateral metacarpals and metatarsals of _Hipparion_. Not
unfrequently, however, the lower ends of the splint-bones carry a small
expansion, representing the phalanges.
Remains of horses indistinguishable from _E. caballus_ occur in the
Pleistocene deposits of Europe and Asia; and it is from them that the
dun-coloured small horses of northern Europe and Asia are probably
derived. The ancestor of these Pleistocene horses is probably _E.
stenonis_, of the Upper Pliocene of Europe, which has a small depression
in front of the orbit, while the skull is relatively larger, the feet
are rather shorter, and the splint-bones somewhat more developed. In
India a nearly allied species (_E. sivalensis_), occurs in the Lower
Pliocene, and may have been the ancestor of the Arab stock, which shows
traces of the depression in front of the orbit characteristic of the
earlier forms. In North America species of _Equus_ occur in the
Pleistocene and from that continent others reached South America during
the same epoch. In the latter country occurs _Hippidium_, in which the
cheek-teeth are shorter and simpler, and the nasal bones very long and
slender, with elongated slits at the side. The limbs, especially the
cannon-bones, are relatively short, and the splint-bones large. The
allied Argentine _Onohippidium_, which is also Pleistocene, has still
longer nasal bones and slits, and a deep double cavity in front of the
orbit, part of which probably contained a gland. _Onohippidium_ is
certainly off the direct line of descent of the modern horses, and, on
account of the length of the nasals and their slits, the same probably
holds good for _Hippidium_.
[Illustration: FIG. 2.--a, Grinding surface of unworn right upper molar
tooth of _Anchitherium_; b, corresponding surface of unworn molar of
young horse; c, the same tooth after it has been some time in use. The
uncoloured portions are the dentine or ivory, the shaded parts the
cement filling the cavities and surrounding the exterior. The black line
separating these two structures is the enamel or hardest constituent of
the tooth.]
Species from the Pliocene of Texas and the Upper Miocene (Loup Fork) of
Oregon were at one time assigned to _Hippidium_, but this is incorrect,
that genus being exclusively South American. The name _Pliohippus_ has
been applied to species from the same two formations on the supposition
that the foot-structure was similar to that of _Hippidium_, but Mr J.W.
Gidley is of opinion that the lateral digits may have been fully
developed.
Apparently there is here some gap in the line of descent of the horse,
and it may be suggested that the evolution took place, not as commonly
supposed, in North America, but in eastern central Asia, of which the
palaeontology is practically unknown; some support is given to this
theory by the fact that the earliest species with which we are
acquainted occur in northern India.
[Illustration: FIG. 3.--Successive stages of modification of the left
fore-feet of extinct forms of horse-like animals, showing gradual
reduction of the outer and enlargement of the middle toe (III).
a, _Hyracotherium_ (Eocene).
b, _Mesohippus_ (Oligocene).
c, _Anchitherium_ (Miocene).
d, _Hipparion_ (Pliocene).
e, _Equus_ (Pleistocene).]
Be this as it may, the next North American representatives of the family
constitute the genera _Protohippus_ and _Merychippus_ of the Miocene, in
both of which the lateral digits are fully developed and terminate in
small though perfect hoofs. In both the cheek-teeth have moderately tall
crowns, and in the first named of the two those of the milk-series are
nearly similar to their permanent successors. In _Merychippus_, on the
other hand, the milk-molars have short crowns, without any cement in the
hollows, thus resembling the permanent molars of the under-mentioned
genus _Anchitherium_. From the well-known _Hipparion_, or
_Hippotherium_, typically from the Lower Pliocene of Europe, but also
occurring in the corresponding formation in North Africa, Persia, India
and China, and represented in the Upper Miocene Loup Fork beds of the
United States by species which it has been proposed to separate
generically as _Neohipparion_, we reach small horses which are now
generally regarded as a lateral offshoot from the _Merychippus_ type.
The cheek-teeth, which have crowns of moderate height, differ from those
of all the foregoing in that the postero-internal pillar (the projection
on the right-hand top corner of c in fig. 2) is isolated in place of
being attached by a narrow neck to the adjacent crescent. The skull,
which is relatively short, has a large depression in front of the orbit,
commonly supposed to have contained a gland, but this may be doubtful.
In the typical, and also in the North American forms these were
complete, although small, lateral toes in both feet (fig. 3, d), but it
is possible that in _H. antilopinum_ of India the lateral toes had
disappeared. If this be so, we have the development of a monodactyle
foot in this genus independently of _Equus_.
The foregoing genera constitute the subfamily _Equinae_, or the
_Equidae_ as restricted by the older writers. In all the dentition is of
the hypsodont type, with the hollows of the cheek-teeth filled by
cement, the premolars molariform, and the first small and generally
deciduous. The orbit is surrounded by a bony ring; the ulna and radius
in the fore, and the tibia and fibula in the hind-limb are united, and
the feet are of the types described above. Between this subfamily and
the second subfamily, _Hyracotheriinae_, a partial connexion is formed
by the North American Upper Miocene genera _Desmatippus_ and _Anchippus_
or _Parahippus_. The characteristics of the group will be gathered from
the remarks on the leading genera; but it may be mentioned that the
orbit is open behind, the cheek-teeth are short-crowned and without
cement (fig. 1, a), the gap between the canine and the outermost
incisor is short, the bones of the middle part of the leg are separate,
and there are at least three toes to each foot.
The longest-known genus and the one containing the largest species is
_Anchitherium_, typically from the Middle Miocene of Europe, but also
represented by one species from the Upper Miocene of North America. The
European _A. aurelianense_ was of the size of an ordinary donkey. The
cheek-teeth are of the type shown in a of figs. 1 and 2; the premolars,
with the exception of the small first one, being molar-like; and the
lateral toes (fig. 3, c) were to some extent functional. The summits of
the incisors were infolded to a small extent. Nearly allied is the
American _Mesohippus_, ranging from the Lower Miocene to the Lower
Oligocene of the United States, of which the earliest species stood only
about 18 in. at the shoulder. The incisors were scarcely, if at all,
infolded, and there is a rudiment of the fifth metacarpal (fig. 3, b).
By some writers all the species of _Mesohippus_ are included in the
genus _Miohippus_, but others consider that the two genera are distinct.
_Mesohippus_ and _Miohippus_ are connected with the earliest and most
primitive mammal which it is possible to include in the family _Equidae_
by means of _Epihippus_ of the Uinta or Upper Eocene of North America,
and _Pachynolophus_, or _Orohippus_, of the Middle and Lower Eocene of
both halves of the northern hemisphere. The final stage, or rather the
initial stage, in the series is presented by _Hyracotherium_
(_Protorohippus_), a mammal no larger than a fox, common to the Lower
Eocene of Europe and North America. The general characteristics of this
progenitor of the horses are those given above as distinctive of the
group. The cheek-teeth are, however, much simpler than those of
_Anchitherium_; the transverse crests of the upper molars not being
fully connected with the outer wall, while the premolars in the upper
jaw are triangular, and thus unlike the molars. The incisors are small
and the canines scarcely enlarged; the latter having a gap on each side
in the lower, but only one on their hinder aspect in the upper jaw. The
fore-feet have four complete toes (fig. 3, a), but there are only three
hind-toes, with a rudiment of the fifth metatarsal. The vertebrae are
simpler in structure than in _Equus_. From _Hyracotherium_, which is
closely related to the Eocene representatives of the ancestral stocks of
the other three branches of the Perissodactyla, the transition is easy
to _Phenacodus_, the representative of the common ancestor of all the
Ungulata.
See also H.F. Osborn, "New Oligocene Horses," _Bull. Amer. Mus._ vol.
xx. p. 167 (1904); J.W. Gidley, _Proper Generic Names of Miocene
Horses_, p. 191; and the article PALAEONTOLOGY. (R. L.*)
EQUILIBRIUM (from the Lat. _aequus_, equal, and _libra_, a balance), a
condition of equal balance between opposite or counteracting forces. By
the "sense of equilibrium" is meant the sense, or sensations, by which
we have a feeling of security in standing, walking, and indeed in all
the movements by which the body is carried through space. Such a feeling
of security is necessary both for maintaining any posture, such as
standing, or for performing any movement. If this feeling is absent or
uncertain, or if there are contradictory sensations, then definite
muscular movements are inefficiently or irregularly performed, and the
body may stagger or fall. When we stand erect on a firm surface, like a
floor, there is a feeling of resistance, due to nervous impulses
reaching the brain from the soles of the feet and from the muscles of
the limbs and trunk. In walking or running, these feelings of resistance
seem to precede and guide the muscular movements necessary for the next
step. If these are absent or perverted or deficient, as is the case in
the disease known as locomotor ataxia, then, although there is no loss
of the power of voluntary movement, the patient staggers in walking,
especially if he is not allowed to look at his feet, or if he is
blind-folded. He misses the guiding sensations that come from the limbs;
and with a feeling that he is walking on a soft substance, offering
little or no resistance, he staggers, and his muscular movements become
irregular. Such a condition maybe artificially brought about by washing
the soles of the feet with chloroform or ether. And it has been observed
to exist partially after extensive destruction of the skin of the soles
of the feet by burns or scalds. This shows that tactile impulses from
the skin take a share in generating the guiding sensation. In the
disease above mentioned, however, tactile impressions may be nearly
normal, but the guiding sensation is weak and inefficient, owing to the
absence of impulses from the muscles. The disease is known to depend on
morbid changes in the posterior columns of the spinal cord, by which
impulses are not freely transmitted upwards to the brain. These facts
point to the existence of impulses coming from the muscles and tendons.
It is now known that there exist peculiar spindles, in muscle, and
rosettes or coils or loops of nerve fibres in close proximity to
tendons. These are the end organs of the sense. The transmission of
impulses gives rise to the _muscular sense_, and the guiding sensation
which precedes co-ordinated muscular movements depends on these
impulses. Thus from the limbs streams of nervous impulses pass to the
sensorium from the skin and from muscles and tendons; these may or may
not arouse consciousness, but they guide or evoke muscular movements of
a co-ordinated character, more especially of the limbs.
In animals whose limbs are not adapted for delicate touch nor for the
performance of complicated movements, such as some mammals and birds and
fishes, the guiding sensations depend largely on the sense of vision.
This sense in man, instead of assisting, sometimes disturbs the guiding
sensation. It is true that in locomotor ataxia visual sensations may
take the place of the tactile and muscular sensations that are
inefficient, and the man can walk without staggering if he is allowed to
look at the floor, and especially if he is guided by transverse straight
lines. On the other hand, the acrobat on the wire-rope dare not trust
his visual sensations in the maintenance of his equilibrium. He keeps
his eyes fixed on one point instead of allowing them to wander to
objects below him, and his muscular movements are regulated by the
impulses that come from the skin and muscles of his limbs. The feeling
of insecurity probably arises from a conception of height, and also from
the knowledge that by no muscular movements can a man avoid a
catastrophe if he should fall. A bird, on the other hand, depends
largely on visual impressions, and it knows by experience that if
launched into the air from a height it can fly. Here, probably, is an
explanation of the large size of the eyes of birds. Cover the head, as
in hooding a falcon, and the bird seems to be deprived of the power of
voluntary movement. Little effect will be produced if we attempt to
restrain the movements of a cat by covering its eyes. A fish also is
deprived of the power of motion if its eyes are covered. But both in the
bird and in the fish tactile and muscular impressions, especially the
latter, come into play in the mechanism of equilibrium. In flight the
large-winged birds, especially in soaring, can feel the most delicate
wind-pressures, both as regards direction and force, and they adapt the
position of their body so as to catch the pressure at the most efficient
angle. The same is true of the fish, especially of the flat-fishes. In
mammals the sense of equilibrium depends, then, on streams of tactile,
muscular and visual impressions pouring in on the sensorium, and calling
forth appropriate muscular movements. It has also been suggested that
impulses coming from the abdominal viscera may take part in the
mechanism. The presence in the mesentery of felines (cats, &c.) of large
numbers of Pacinian corpuscles, which are believed to be modified
tactile bodies, favours this supposition. Such animals are remarkable
for the delicacy of such muscular movements, as balancing and leaping.
There is another channel by which nervous impulses reach the sensorium
and play their part in the sense of equilibrium, namely, from the
semicircular canals, a portion of the internal ear. It is pointed out in
the article HEARING that the appreciation of sound is in reality an
appreciation of variations of pressure. The labyrinth consists of the
vestibule, the cochlea and the semicircular canals. The cochlea receives
the sound-waves (variations of pressure) that constitute musical tones.
This it accomplishes by the structures in the ductus cochlearis. In the
vestibule we find two sacs, the saccule next to and communicating with
the ductus cochlearis, and the utricle communicating with the
semicircular canals. The base of the stapes communicates pressures to
the utricle. The membranous portion of the semicircular canals consists
of a tube, dilated at one end into a swelling or pouch, termed the
ampulla, and each end communicates freely with the utricle. On the
posterior wall of both the saccule and of the utricle there is a ridge,
termed in each case the macula acustica, bearing a highly specialized
epithelium. A similar structure exists in each ampulla. This would
suggest that all three structures have to do with hearing; but, on the
other hand, there is experimental evidence that the utricle and the
canals may transmit impressions that have to do with equilibrium.
Pressure of the base of the stapes is exerted on the utricle. This will
compress the fluid in that cavity, and tend to drive the fluid into the
semicircular canals that communicate with that cavity by five openings.
Each canal is surrounded by a thin layer of perilymph, so that it may
yield a little to this pressure, and exert a pull or pressure on the
nerve-endings in each ampulla. Thus impulses may be generated in the
nerves of the ampullae.
The three semicircular canals lie in the three directions in space, and
it has been suggested that they have to do with our appreciation of the
direction of sound. But our appreciation of sound is very inaccurate: we
look with the eyes for the source of a sound, and instinctively direct
the ears or the head, or both, in the direction from which the sound
appears to proceed. But the relationship of the canals on the two sides
must have a physiological significance. Thus (1) the six canals are
parallel, two and two; or (2) the two horizontal canals are in the same
plane, while the superior canal on one side is nearly parallel with the
posterior canal of the other. These facts point to the two sets of
canals and ampullae acting as one organ, in a manner analogous to the
action of two retinae for single vision.
We have next to consider how the canals may possibly act in connexion
with the sense of equilibrium. In 1820 J. Purkinje studied the vertigo
that follows rapid rotation of the body in the erect position on a
vertical axis. On stopping the rotation there is a sense of rotation in
the opposite direction, and this may occur even when the eyes are
closed. Purkinje noticed that the position of the imaginary axis of
rotation depends on the axis around which the head revolves. In 1828
M.J.P. Flourens discovered that injury to the canals causes disturbance
to the equilibrium and loss of co-ordination, and that sections of the
canals produce a rotatory movement of a kind corresponding to the canal
that had been divided. Thus division of a membranous canal causes
rotatory movements round an axis at right angles to the plane of the
divided canal. The body of the animal always moves in the direction of
the cut canal. Many other observers have corroborated these experiments.
F. Goltz was the first who formulated the conditions necessary for
equilibration. He put the matter thus:--(1) A central co-ordinating
organ--in the brain; (2) centripetal fibres, with their peripheral
terminations--in the ampullae; and (3) centrifugal fibres, with their
terminal organs--in the muscular mechanisms. A lesion of any one of
these portions of the mechanism causes loss or impairment of balancing.
Cyon also investigated the subject, and concluded:--(1) To maintain
equilibrium, we must have an accurate notion of the position of the head
in space; (2) the function of the semicircular canals is to communicate
impressions that give a representation of this position--each canal
having a relation to one of the dimensions of space; (3) disturbance of
equilibrium follows section; (4) involuntary movements following section
are due to abnormal excitations; (5) abnormal movements occurring a few
days after the operation are caused by irritation of the cerebellum.
On theoretical considerations of a physical character, E. Mach,
Crum-Brown and Breuer have advanced theories based on the idea of the
canals being organs for sensations of acceleration of movement, or for
the sense of rotation. Mach first pointed out that Purkinje's phenomena,
already alluded to, were in all probability related to the semicircular
canals. "He showed that when the body is moved in space, in a straight
line, we are not conscious of the velocity of motion, but of variations
in this velocity. Similarly, if a body is rotated round a vertical axis,
we perceive only angular acceleration and not angular velocity. The
sensations produced by angular acceleration last longer than the
acceleration itself, and the position of the head during the movements
enables us to determine direction." Both Mach and Goltz state that
varying pressures of the fluid in the canals produced by angular
rotation produce sensations of movement (always in a direction opposite
to the rotation of the body), and that these, in turn, cause the vertigo
of Purkinje and the phenomena of Flourens. Mach, Crum-Brown and Breuer
advance hydrodynamical theories in which they assume that the fluids
move in the canals. Goltz, on the other hand, supports a hydrostatical
theory in which he assumes that the phenomena can be accounted for by
varying pressures. Crum-Brown differs from Mach and Breuer as
follows:--(1) In attributing movement or variation of pressure not
merely to the endolymph, but also to the walls of the membranous canals
and to the surrounding perilymph; and (2) in regarding the two
labyrinths as one organ, all the six canals being required to form a
true conception of the rotating motion of the head. He sums up the
matter thus: "We have two ways in which a relative motion can occur
between the endolymph and the walls of the cavity containing it--(1)
When the head begins to move, here the walls leave the fluid behind; (2)
when the head stops, here the fluid flows on. In both cases the
sensation of rotation is felt. In the first this sensation corresponds
to a real rotation, in the second it does not, but in both it
corresponds to a real acceleration (positive or negative) of rotation,
using the word acceleration in its technical kinematical sense."
Cyon states that the semicircular canals only indirectly assist in
giving a notion of spatial relations. "He holds that knowledge of the
position of bodies in space depends on nervous impulses coming from the
contracting ocular muscles; that the oculomotor centres are in intimate
physiological relationship with the centres receiving impulses from the
nerves of the semicircular canals; and that the oculomotor centres, thus
excited, produce the movements of the eyeballs, which then determine our
notions of spatial relations." These views are supported by experiments
of Lee on dog-fish. When the fish is rotated round different axes there
are compensating movements of the eyes and fins. "It was observed that
if the fish were rotated in the plane of one of the canals, exactly the
same movements of the eyes and fins occurred as were produced by
experimental operation and stimulation of the ampulla of that canal."
Sewall, in 1883, carried out experiments on young sharks and skates with
negative results. Lee returned to the subject in 1894, and, after
numerous experiments on dog-fish, in which the canals or the auditory
nerves were divided, obtained evidence that the ampullae contain
sense-organs connected with the sense of equilibrium.
It has been found by physicians and aurists that disease or injury of
the canals, occurring rapidly, produces giddiness, staggering, nystagmus
(a peculiar twitching movement of the muscles of the eyeballs),
vomiting, noises in the ear and more or less deafness. It is said,
however, that if pathological changes come on slowly, so that the canals
and vestibule are converted into a solid mass, none of these symptoms
may occur. On the whole, the evidence is in favour of the view that from
the semicircular canals nervous impulses are transmitted, which,
co-ordinated with impulses coming from the visual organs, from the
muscles and from the skin, form the bases of these guiding sensations on
which the sense of equilibrium depends. These impulses may not reach the
level of consciousness, but they call into action co-ordinated
mechanisms by which complicated muscular movements are effected.
Full bibliographical references are given in the article on "The Ear"
by J.G. McKendrick, in Schafer's _Textbook of Physiology_, vol. ii. p.
1194. (J. G. M.)
EQUINOX (from the Lat. _aequus_, equal, and _nox_, night), a term used
to express either the moment at which, or the point at which, the sun
apparently crosses the celestial equator. Since the sun moves in the
ecliptic, it is in the last-named sense the point of intersection of the
ecliptic and the celestial equator. This is the usual meaning of the
term in astronomy. There are 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 [Greek: keles], "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 L3500 to L4000).
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 _equites-publicani_ formed a close financial
corporation of about 30,000 members, holding an intermediate position
between the nobility and the lower classes, keenly alive to their own
interests, and ready to stand by one another when attacked. Although to
some extent looked down upon by the senate as following a dishonourable
occupation, they had as a rule sided with the latter, as being at least
less hostile to them than the democratic party. To obtain the support of
the capitalists, Gaius Gracchus conceived the plan of creating friction
between them and the senate, which he carried out by handing over to
them the control (a) of the jury-courts, and (b) of the revenues of
Asia.
(a) Hitherto, the list of jurymen for service in the majority of
processes, both civil and criminal, had been composed exclusively of
senators. The result was that charges of corruption and extortion
failed, when brought against members of that order, even in cases where
there was little doubt of their guilt. The popular indignation at such
scandalous miscarriages of justice rendered a change in the composition
of the courts imperative. Apparently Gracchus at first proposed to
create new senators from the equites and to select the jurymen from this
mixed body, but this moderate proposal was rejected in favour of one
more radical (see W.W. Fowler in _Classical Review_, July 1896). By the
lex Sempronia (123 B.C.) the list was to be drawn from persons of free
birth over thirty years of age, who must possess the equestrian census,
and must not be senators. Although this measure was bound to set
senators and equites at variance, it in no way improved the lot of those
chiefly concerned. In fact, it increased the burden of the luckless
provincials, whose only appeal lay to a body of men whose interests were
identical with those of the _publicani_. Provided he left the
tax-gatherer alone, the governor might squeeze what he could out of the
people, while on the other hand, if he were humanely disposed, it was
dangerous for him to remonstrate.
(b) The taxes of Asia had formerly been paid by the inhabitants
themselves in the shape of a fixed sum. Gracchus ordered that the taxes,
direct and indirect, should be increased, and that the farming of them
should be put up to auction at Rome. By this arrangement the provincials
were ignored, and everything was left in the hands of the capitalists.
From this time dates the existence of the equestrian order as an
officially recognized political instrument. When the control of the
courts passed into the hands of the property equites, all who were
summoned to undertake the duties of judices were called equites; the
_ordo judicum_ (the official title) and the _ordo equester_ were
regarded as identical. It is probable that certain privileges of the
equites were due to Gracchus; that of wearing the gold ring, hitherto
reserved for senators; that of special seats in the theatre,
subsequently withdrawn (probably by Sulla) and restored by the lex
Othonis (67 B.C.); the narrow band of purple on the tunic as
distinguished from the broad band worn by the senators.
Various attempts were made by the senate to regain control of the
courts, but without success. The lex Livia of M. Livius Drusus (q.v.),
passed with that object, but irregularly and by the aid of violence, was
annulled by the senate itself. In 82 Sulla restored the right of serving
as judices to the senate, to which he elevated 300 of the most
influential equites, whose support he thus hoped to secure; at the same
time he indirectly dealt a blow at the order generally, by abolishing
the office of the censor (immediately revived), in whom was vested the
right of bestowing the public horse. To this period Mommsen assigns the
regulation, generally attributed to Augustus, that the sons of senators
should be knights by right of birth. By the lex Aurelia (70 B.C.) the
judices were to be chosen in equal numbers from senators, equites and
tribuni aerarii (see AERARIUM), (the last-named being closely connected
with the equites), who thus practically commanded a majority. About this
time the influence of the equestrian order reached its height, and
Cicero's great object was to reconcile it with the senate. In this he
was successful at the time of the Catilinarian conspiracy, in the
suppression of which he was materially aided by the equites. But the
union did not last long; shortly afterwards the majority ranged
themselves on the side of Julius Caesar, who did away with the tribuni
aerarii as judices, and replaced them by equites.
Augustus undertook the thorough reorganization of the equestrian order
on a military basis. The _equites equo privato_ were abolished
(according to Herzog, not till the reign of Tiberius) and the term
equites was officially limited to the _equites equo publico_, although
all who possessed the property qualification were still considered to
belong to the "equestrian order." For the _equites equo publico_ high
moral character, good health and the equestrian fortune were necessary.
Although free birth was considered indispensable, the right of wearing
the gold ring (_jus anuli aurei_) was frequently bestowed by the emperor
upon freedmen, who thereby became _ingenui_ and eligible as equites.
Tiberius, however, insisted upon free birth on the father's side to the
third generation. Extreme youth was no bar; the emperor Marcus Aurelius
had been an eques at the age of six. The sons of senators were eligible
by right of birth, and appear to have been known as _equites illustres_.
The right of bestowing the _equus publicus_ was vested in the emperor;
once given, it was for life, and was only forfeitable through
degradation for some offence or the loss of the equestrian fortune.
Augustus divided the equites into six _turmae_ (regarded by Hirschfeld
as a continuation of the _sex suffragia_). Each was under the command of
a _sevir_ ([Greek: hilarchos]), who was appointed by the emperor and
changed every year. During their term of command the _seviri_ had to
exhibit games (_ludi sevirales_). Under these officers the equites
formed a kind of corporation, which, although not officially recognized,
had the right of passing resolutions, chiefly such as embodied acts of
homage to the imperial house. It is not known whether the _turmae_
contained a fixed number of equites; there is no doubt that, in
assigning the public horse, Augustus went far beyond the earlier figure
of 1800. Thus, Dionysius of Halicarnassus mentions 5000 equites as
taking part in a review at which he himself was present.
As before, the equites wore the narrow, purple-striped tunic, and the
gold ring, the latter now being considered the distinctive badge of
knighthood. The fourteen rows in the theatre were extended by Augustus
to seats in the circus.
The old _recognitio_ was replaced by the _probatio_, conducted by the
emperor in his censorial capacity, assisted by an advisory board of
specially selected senators. The ceremony was combined with a
procession, which, like the earlier _transvectio_, took place on the
15th of July, and at such other times as the emperor pleased. As in
earlier times, offenders were punished by expulsion.
In order to provide a supply of competent officers, each eques was
required to fill certain subordinate posts, called _militiae equestres_.
These were (1) the command of an auxiliary cohort; (2) the tribunate of
a legion; (3) the command of an auxiliary cavalry squadron, this order
being as a rule strictly adhered to. To these Septimius Severus added
the centurionship. Nomination to the _militiae equestres_ was in the
hands of the emperor. After the completion of their preliminary military
service, the equites were eligible for a number of civil posts, chiefly
those with which the emperor himself was closely concerned. Such were
various procuratorships; the prefectures of the corn supply, of the
fleet, of the watch, of the praetorian guards; the governorships of
recently acquired provinces (Egypt, Noricum), the others being reserved
for senators. At the same time, the abolition of the indirect method of
collecting the taxes in the provinces greatly reduced the political
influence of the equites. Certain religious functions of minor
importance were also reserved for them. In the jury courts, the equites,
thanks to Julius Caesar, already formed two-thirds of the judices;
Augustus, by excluding the senators altogether, virtually gave them the
sole control of the tribunals. One of the chief objects of the emperors
being to weaken the influence of the senate by the opposition of the
equestrian order, the practice was adopted of elevating those equites
who had reached a certain stage in their career to the rank of senator
by _adlectio_. Certain official posts, of which it would have been
inadvisable to deprive senators, could thus be bestowed upon the
promoted equites.
The control of the imperial correspondence and purse was at first in
the hands of freedmen and slaves. The emperor Claudius tentatively
entrusted certain posts connected with these to the equites; in the time
of Hadrian this became the regular custom. Thus a civil career was open
to the equites without the obligation of preliminary military service,
and the emperor was freed from the pernicious influence of freedmen.
After the reign of Marcus Aurelius (according to Mommsen) the equites
were divided into: (a) _viri eminentissimi_, the prefects of the
praetorian guard; (b) _viri perfectissimi_, the other prefects and the
heads of the financial and secretarial departments; (c) _viri egregii_,
first mentioned in the reign of Antoninus Pius, a title by right of the
procurators generally.
Under the empire the power of the equites was at its highest in the time
of Diocletian; in consequence of the transference of the capital to
Constantinople, they sank to the position of a mere city guard, under
the control of the prefect of the watch. Their history may be said to
end with the reign of Constantine the Great.
Mention may also be made of the _equites singulares Augusti_. The
body-guard of Augustus, consisting of foreign soldiers (chiefly Germans
and Batavians), abolished by Galba, was revived from the time of Trajan
or Hadrian under the above title. It was chiefly recruited from the pick
of the provincial cavalry, but contained some Roman citizens. It formed
the imperial "Swiss guard," and never left the city except to accompany
the emperor. In the time of Severus, these equites were divided into two
corps, each of which had its separate quarters, and was commanded by a
tribune under the orders of the prefect of the praetorian guard. They
were subsequently replaced by the _protectores Augusti_.
See further article ROME: _History_; also T. Mommsen, _Romisches
Staatsrecht_, iii.; J.N. Madvig, _Die Verfassung des romischen
Staates_, i.; R. Cagnat in Daremberg and Saglio's _Dictionnaire des
antiquites_, where full references to ancient authorities are given in
the footnotes; A.S. Wilkins in Smith's _Dictionary of Greek and Roman
Antiquities_ (3rd ed., 1891); E. Belot, _Histoire des chevaliers
romains_ (1866-1873); H.O. Hirschfeld, _Untersuchungen auf dem Gebiete
der romischen Verwaltungsgeschichte_ (Berlin, 1877); E. Herzog,
_Geschichte und System der romischen Staatsverfassung_ (Leipzig,
1884-1891); A.H. Friedlander, _Sittengeschichte Roms_, i. (1901);
A.H.J. Greenidge, _History of Rome_, i. (1904); J.B. Bury, _The
Student's Roman Empire_ (1893); T.M. Taylor, _Political and
Constitutional History of Rome_ (1899). For a concise summary of
different views of the _sex suffragia_ see A. Bouche-Leclercq's
_Manuel des antiquites romaines_, quoted in Daremberg and Saglio; and
on the _equites singulares_, T. Mommsen in _Hermes_, xvi. (1881), p.
458. (J. H. F.)
EQUITY (Lat. _aequitas_), a term which in its most general sense means
equality or justice; in its most technical sense it means a system of
law or a body of connected legal principles, which have superseded or
supplemented the common law on the ground of their intrinsic
superiority. Aristotle (_Ethics_, bk. v. c. 10) defines equity as a
better sort of justice, which corrects legal justice where the latter
errs through being expressed in a universal form and not taking account
of particular cases. When the law speaks universally, and something
happens which is not according to the common course of events, it is
right that the law should be modified in its application to that
particular case, as the lawgiver himself would have done, if the case
had been present to his mind. Accordingly the equitable man ([Greek:
epieikes]) is he who does not push the law to its extreme, but, having
legal justice on his side, is disposed to make allowances. Equity as
thus described would correspond rather to the judicial discretion which
modifies the administration of the law than to the antagonistic system
which claims to supersede the law.
The part played by equity in the development of law is admirably
illustrated in the well-known work of Sir Henry Maine on _Ancient Law_.
Positive law, at least in progressive societies, is constantly tending
to fall behind public opinion, and the expedients adopted for bringing
it into harmony therewith are three, viz. legal fictions, equity and
statutory legislation. Equity here is defined to mean "any body of rules
existing by the side of the original civil law, founded on distinct
principles, and claiming incidentally to supersede the civil law in
virtue of a superior sanctity inherent in those principles." It is thus
different from legal fiction, by which a new rule is introduced
surreptitiously, and under the pretence that no change has been made in
the law, and from statutory legislation, in which the obligatory force
of the rule is not supposed to depend upon its intrinsic fitness. The
source of Roman equity was the fertile theory of natural law, or the law
common to all nations. Even in the Institutes of Justinian the
distinction is carefully drawn in the laws of a country between those
which are peculiar to itself and those which natural reason appoints for
all mankind. The connexion in Roman law between the ideas of equity,
nature, natural law and the law common to all nations, and the influence
of the Stoical philosophy on their development, are fully discussed in
the third chapter of the work we have referred to. The agency by which
these principles were introduced was the edicts of the praetor, an
annual proclamation setting forth the manner in which the magistrate
intended to administer the law during his year of office. Each
successive praetor adopted the edict of his predecessor, and added new
equitable rules of his own, until the further growth of the irregular
code was stopped by the praetor Salvius Julianus in the reign of
Hadrian.
The place of the praetor was occupied in English jurisprudence by the
lord high chancellor. The real beginning of English equity is to be
found in the custom of handing over to that officer, for adjudication,
the complaints which were addressed to the king, praying for remedies
beyond the reach of the common law. Over and above the authority
delegated to the ordinary councils or courts, a reserve of judicial
power was believed to reside in the king, which was invoked as of grace
by the suitors who could not obtain relief from any inferior tribunal.
To the chancellor, as already the head of the judicial system, these
petitions were referred, although he was not at first the only officer
through whom the prerogative of grace was administered. In the reign of
Edward III. the equitable jurisdiction of the court appears to have been
established. Its constitutional origin was analogous to that of the star
chamber and the court of requests. The latter, in fact, was a minor
court of equity attached to the lord privy seal as the court of chancery
was to the chancellor. The successful assumption of extraordinary or
equitable jurisdiction by the chancellor caused similar pretensions to
be made by other officers and courts. "Not only the court of exchequer,
whose functions were in a peculiar manner connected with royal
authority, but the counties palatine of Chester, Lancaster and Durham,
the court of great session in Wales, the universities, the city of
London, the Cinque Ports and other places silently assumed extraordinary
jurisdiction similar to that exercised in the court of chancery." Even
private persons, lords and ladies, affected to establish in their
honours courts of equity.
English equity has one marked historical peculiarity, viz. that it
established itself in a set of independent tribunals which remained in
standing contrast to the ordinary courts for many hundred years. In
Roman law the judge gave the preference to the equitable rule; in
English law the equitable rule was enforced by a distinct set of judges.
One cause of this separation was the rigid adherence to precedent on the
part of the common law courts. Another was the jealousy prevailing in
England against the principles of the Roman law on which English equity
to a large extent was founded.
When a case of prerogative was referred to the chancellor in the reign
of Edward III., he was required to grant such remedy as should be
consonant to honesty (_honestas_). And honesty, conscience and equity
were said to be the fundamental principles of the court. The early
chancellors were ecclesiastics, and under their influence not only moral
principles, where these were not regarded by the common law, but also
the equitable principles of the Roman law were introduced into English
jurisprudence. Between this point and the time when equity became
settled as a portion of the legal system, having fixed principles of its
own, various views of its nature seem to have prevailed. For a long time
it was thought that precedents could have no place in equity, inasmuch
as it professed in each case to do that which was just; and we find this
view maintained by common lawyers after it had been abandoned by the
professors of equity themselves. G. Spence, in his book on the
_Equitable Jurisdiction of the Court of Chancery_, quotes a case in
the reign of Charles II., in which chief justice Vaughan said:
"I wonder to hear of citing of precedents in matter of equity, for if
there be equity in a case, that equity is an universal truth, and
there can be no precedent in it; so that in any precedent that can be
produced, if it be the same with this case, the reason and equity is
the same in itself; and if the precedent be not the same case with
this it is not to be cited."
But the lord keeper Bridgeman answered:
"Certainly precedents are very necessary and useful to us, for in them
we may find the reasons of the equity to guide us, and besides the
authority of those who made them is much to be regarded. We shall
suppose they did it upon great consideration and weighing of the
matter, and it would be very strange and very ill if we should disturb
and set aside what has been the course for a long series of times and
ages."
Selden's description is well known: "Equity is a roguish thing. 'Tis all
one as if they should make the standard for measure the chancellor's
foot." Lord Nottingham in 1676 reconciled the ancient theory and the
established practice by saying that the conscience which guided the
court was not the natural conscience of the man, but the civil and
political conscience of the judge. The same tendency of equity to settle
into a system of law is seen in the recognition of its limits--in the
fact that it did not attempt in all cases to give a remedy when the rule
of the common law was contrary to justice. Cases of hardship, which the
early chancellors would certainly have relieved, were passed over by
later judges, simply because no precedent could be found for their
interference. The point at which the introduction of new principles of
equity finally stopped is fixed by Sir Henry Maine in the chancellorship
of Lord Eldon, who held that the doctrines of the court ought to be as
well settled and made as uniform almost as those of the common law. From
that time certainly equity, like common law, has professed to take its
principles wholly from recorded decisions and statute law. The view
(traceable no doubt to the Aristotelian definition) that equity
mitigates the hardships of the law where the law errs through being
framed in universals, is to be found in some of the earlier writings.
Thus in the _Doctor and Student_ it is said:
"Law makers take heed to such things as may often come, and not to
every particular case, for they could not though they would;
therefore, in some cases it is necessary to leave the words of the law
and follow that reason and justice requireth, and to that intent
equity is ordained, that is to say, to temper and mitigate the rigour
of the law."
And Lord Ellesmere said:
"The cause why there is a chancery is for that men's actions are so
divers and infinite that it is impossible to make any general law
which shall aptly meet with every particular act and not fail in some
circumstances."
Modern equity, it need hardly be said, does not profess to soften the
rigour of the law, or to correct the errors into which it falls by
reason of its generality.
To give any account, even in outline, of the subject matter of equity
within the necessary limits of this article would be impossible. It will
be sufficient to say here that the classification generally adopted by
text-writers is based upon the relations of equity to the common law, of
which some explanation is given above. Thus equitable jurisdiction is
said to be exclusive, concurrent or auxiliary. Equity has _exclusive_
jurisdiction where it recognizes rights which are unknown to the common
law. The most important example is trusts. Equity has _concurrent_
jurisdiction in cases where the law recognized the right but did not
give adequate relief, or did not give relief without circuity of action
or some similar inconvenience. And equity has _auxiliary_ jurisdiction
when the machinery of the courts of law was unable to procure the
necessary evidence.
"The evils of this double system of judicature," says the report of the
judicature commission (1863-1867), "and the confusion and conflict of
jurisdiction to which it has led, have been long known and
acknowledged." A partial attempt to meet the difficulty was made by
several acts of parliament (passed after the reports of commissions
appointed in 1850 and 1851), which enabled courts of law and equity both
to exercise certain powers formerly peculiar to one or other of them. A
more complete remedy was introduced by the Judicature Act 1873, which
consolidated the courts of law and equity, and ordered that law and
equity should be administered concurrently according to the rules
contained in the 26th section of the act. At the same time many matters
of equitable jurisdiction are still left to the chancery division of the
High Court in the first instance. (See CHANCERY.)
AUTHORITIES.--The principles of equity as set out by the following
writers may be consulted: J. Story, J.W. Smith, H.A. Smith and W.
Ashburner; and for the history see G. Spence, _The Equitable
Jurisdiction of the Court of Chancery_ (2 vols., 1846-1849); D.M.
Kerly, _Historical Sketch of the Equitable Jurisdiction of the Court
of Chancery_ (1890).
EQUIVALENT, in chemistry, the proportion of an element which will
combine with or replace unit weight of hydrogen. When multiplied by the
valency it gives the atomic weight. The determination of equivalent
weights is treated in the article STOICHIOMETRY. (See also CHEMISTRY.)
In a more general sense the term "equivalent" is used to denote
quantities of substances which neutralize one another, as for example
NaOH, HCl, 1/2 H2SO4, 1/2 Ba(OH)2.
ERARD, SEBASTIEN (1752-1831), French manufacturer of musical
instruments, distinguished especially for the improvements he made upon
the harp and the pianoforte, was born at Strassburg on the 5th of April
1752. While a boy he showed great aptitude for practical geometry and
architectural drawing, and in the workshop of his father, who was an
upholsterer, he found opportunity for the early exercise of his
mechanical ingenuity. When he was sixteen his father died, and he
removed to Paris where he obtained employment with a harpsichord maker.
Here his remarkable constructive skill, though it speedily excited the
jealousy of his master and procured his dismissal, almost equally soon
attracted the notice of musicians and musical instrument makers of
eminence. Before he was twenty-five he set up in business for himself,
his first workshop being a room in the hotel of the duchesse de
Villeroi, who gave him warm encouragement. Here he constructed in 1780
his first pianoforte, which was also one of the first manufactured in
France. It quickly secured for its maker such a reputation that he was
soon overwhelmed with commissions, and finding assistance necessary, he
sent for his brother, Jean Baptiste, in conjunction with whom he
established in the rue de Bourbon, in the Faubourg St Germain, a piano
manufactory, which in a few years became one of the most celebrated in
Europe. On the outbreak of the Revolution he went to London where he
established a factory. Returning to Paris in 1796, he soon afterwards
introduced grand pianofortes, made in the English fashion, with
improvements of his own. In 1808 he again visited London, where, two
years later, he produced his first double-movement harp. He had
previously made various improvements in the manufacture of harps, but
the new instrument was an immense advance upon anything he had before
produced, and obtained such a reputation that for some time he devoted
himself exclusively to its manufacture. It has been said that in the
year following his invention he made harps to the value of L25,000. In
1812 he returned to Paris, and continued to devote himself to the
further perfecting of the two instruments with which his name is
associated. In 1823 he crowned his work by producing his model grand
pianoforte with the double escapement. Erard died at Passy, on the 5th
of August 1831. (See also HARP and PIANOFORTE.)
ERASMUS, DESIDERIUS (1466-1536), Dutch scholar and theologian, was born
on the night of the 27/28th of October, probably in 1466; but his
statements about his age are conflicting, and in view of his own
uncertainty (_Ep._ x. 29: 466) and the weakness of his memory for dates,
the year of his birth cannot be definitely fixed. His father's name
seems to have been Rogerius Gerardus. He himself was christened
Herasmus; but in 1503, when becoming familiar with Greek, he assimilated
the name to a fancied Greek original, which he had a few years before
Latinized into Desyderius. A contemporary authority states that he was
born at Gouda, his father's native town; but he adopted the style
_Rotterdammensis_ or _Roterodamus_, in accordance with a story to which
he himself gave credence. His first schooling was at Gouda under Peter
Winckel, who was afterwards vice-pastor of the church. In the dull round
of instruction in "grammar" he did not distinguish himself, and was
surpassed by his early friend and companion, William Herman, who was
Winckel's favourite pupil. From Gouda the two boys went to the school
attached to St Lebuin's church at Deventer, which was one of the first
in northern Europe to feel the influence of the Renaissance. Erasmus was
at Deventer from 1475 to 1484, and when he left, had learnt from
Johannes Sinthius (Syntheim) and Alexander Hegius, who had come as
headmaster in 1483, the love of letters which was the ruling passion of
his life. At some period, perhaps in an interval of his time at
Deventer, he was a chorister at Utrecht under the famous organist of the
cathedral, Jacob Obrecht.
About 1484 Erasmus' father died, leaving him and an elder brother Peter,
both born out of wedlock, to the care of guardians, their mother having
died shortly before. Erasmus was eager to go to a university, but the
guardians, acting under a perhaps genuine enthusiasm for the religious
life, sent the boys to another school at Hertogenbosch; and when they
returned after two or three years, prevailed on them to enter
monasteries. Peter went to Sion, near Delft; Erasmus after prolonged
reluctance became an Augustinian canon in St Gregory's at Steyn, a house
of the same Chapter near Gouda. There he found little religion and less
refinement; but no serious difficulty seems to have been made about his
reading the classics and the Fathers with his friends to his heart's
content. The monastery once entered, there was no drawing back; and
Erasmus passed through the various stages which culminated in his
ordination as priest on the 25th of April 1492.
But his ardent spirit could not long be content with monastic life. He
brought his attainments somehow to the notice of Henry of Bergen, bishop
of Cambrai, the leading prelate at the court of Brussels; and about 1494
permission was obtained for him to leave Steyn and become Latin
secretary to the bishop, who was then preparing for a visit to Rome. But
the journey was abandoned, and after some months Erasmus found that even
with occasional chances to read at Groenendael, the life of a court was
hardly more favourable to study than that of Steyn. At the suggestion of
a friend, James Batt, he applied to his patron for leave to go to Paris
University. The bishop consented and promised a small pension; and in
August 1495 Erasmus entered the "domus pauperum" of the college of
Montaigu, which was then under the somewhat rigid rule of the reformer
Jan Standonck. He at once introduced himself to the distinguished French
historian and diplomatist Robert Gaguin (1425-1502) and published a
small volume of poems; and he became intimate with Johann Mauburnus
(Mombaer), the leader of a mission summoned from Windesheim in 1496 to
reform the abbey of Chateau-Landon. But the life at Montaigu was too
hard for him. Every Lent he fell ill and had to return to Holland to
recover. He continued to read nevertheless for a degree in theology, and
at some time completed the requirements for the B.D. After a year or two
he left Montaigu and eked out his money from the bishop by taking
pupils. One of these, a young Englishman, William Blount, 4th Baron
Mountjoy (d. 1534), persuaded him to visit England in the spring of
1499.
Being without a benefice, he had no settled income to look to, and apart
from the precarious profits of teaching and writing books, could only
wait on the generosity of patrons to supply him with the leisure he
craved. The faithful Batt had sought a pension for him from his own
patroness, Anne of Borsselen, the Lady of Veere, who resided at the
castle of Tournehem near Calais, and whose son Batt was now teaching.
But as nothing promised at once, Erasmus accepted Mountjoy's offer, and
thus a tie was formed which led Mountjoy then or a few years later to
grant him a pension of L20 for life. Otherwise the visit to England gave
no hope of preferment; and in the summer Erasmus prepared to leave. He
was delayed, and used the interval to spend two or three months at
Oxford, where he found John Colet lecturing on the Epistle to the
Romans. Discussions between them on theological questions soon convinced
Colet of Erasmus' worth, and he sought to persuade him to stay and teach
at Oxford. But Erasmus could not be content with the Bible in Latin.
Oxford could teach him no Greek, so away he must go.
In January 1500 he returned to Paris, which though it could offer no
Greek teacher better than George Hermonymus, was at least a better
centre for buying and for printing books. The next few years were spent
still in preparation, supported by pupils' fees and the dedications of
books; the _Collectanea adagiorum_ in June 1500 to Mountjoy, and some
devotional and moral compositions to Batt's patroness and her son. When
the plague drove him from Paris, he went to Orleans or Tournehem or St
Omer, as the way opened. From 1502 to 1504 he was at Louvain, still
declining to teach publicly; among his friends being the future Pope
Adrian VI. In January 1504 the archduke Philip gave him fifty livres for
the Panegyric which "_ung religieux de l'ordre de St Augustin_" had
composed on his Spanish journey; and in October, ten more, for the
maintenance of his studies.
He had been working hard at Greek, of which he now felt himself master,
at the Fathers (above all at Jerome), and at the Epistles of St Paul,
fulfilling the promise made to Colet in Oxford, to give himself to
sacred learning. But the bent of his reading is shown by the manuscript
with which he returned to Paris at the close of 1504--Valla's
_Annotations on the New Testament_, which Badius printed for him in
1505.
Shortly afterwards Lord Mountjoy invited him again to England, and this
visit was more successful. He found in London a circle of learned
friends through whom he was introduced to William Warham, archbishop of
Canterbury, Richard Foxe, bishop of Winchester and other dignitaries.
John Fisher (bishop of Rochester), who was then superintending the
foundation of Christ's College for the Lady Margaret, took him down to
Cambridge for the king's visit; and at length the opportunity came to
fulfil his dream of seeing Italy. Baptista Boerio, the king's physician,
engaged him to accompany his two sons thither as supervisor of their
studies. In September 1506 he set foot on that sacred soil, and took his
D.D. at Turin. For a year he remained with his pupils at Bologna, and
then, his engagement completed, negotiated with Aldus Manutius for a new
edition of his _Adagia_ upon a very different scale. The volume of 1500
had been jejune, written when he knew nothing of Greek; 800 adages put
together with scanty elucidations. In 1508 he had conceived a work on
lines more to the taste of the learned world, full of apt and recondite
learning, and now and again relieved by telling comments or lively
anecdotes. Three thousand and more collected justified a new
title--_Chiliades adagiorum_; and the author's reputation was now
established. So secure in public favour did the book in time become,
that the council of Trent, unable to suppress it and not daring to
overlook it, ordered the preparation of a castrated edition.
To print the _Adagia_ he had gone to Venice, where he lived with Andrea
Torresano of Asola (Asulanus) and did the work of two men, writing and
correcting proof at the same time. When it was finished, with an ample
re-dedication to Mountjoy, a new pupil presented himself, Alexander
Stewart, natural son of James IV. of Scotland--perhaps through a
connexion formed in early days at Paris. They went together to Siena and
Rome and then on to Campania, thirsty under the summer sun. When they
returned to Rome, his pupil departed to Scotland, to fall a few years
later by his father's side at Flodden; Erasmus also found a summons to
call him northwards.
On the death of Henry VII. Lord Mountjoy, who had been companion to
Prince Henry in his studies, had become a person of influence. He wrote
to Erasmus of a land flowing with milk and honey under the "divine"
young king, and with Warham sent him L10 for journey money. At first
Erasmus hesitated. He had been disappointed in Italy, to find that he
had not much to learn from its famed scholarship; but he had made many
friends in Aldus's circle--Marcus Musurus, John Lascaris, Baptista
Egnatius, Paul Bombasius, Scipio Carteromachus; and his reception had
been flattering, especially in Rome, where cardinals had delighted to
honour him. But to remain in Rome was to sell himself. He might have the
leisure which was so indispensable, but at price of the freedom to read,
think, write what he liked. He decided, therefore, to go, though with
regrets; which returned upon him sometimes in after years, when the
English hopes had not borne fruit.
In the autumn he reached London, and in Thomas More's house in
Bucklersbury wrote the witty satire which Milton found "in every one's
hands" at Cambridge in 1628, and which is read to this day. The _Moriae
encomium_ was a sign of his decision. In it kings and princes, bishops
and popes alike are shown to be in bondage to Folly; and no class of men
is spared. Its author was willing to be beholden to any one for leisure;
but he would be no man's slave. For the next eighteen months he is
entirely lost to view; when he reappears in April 1511, he is leaving
More's house and taking the _Moria_ to be printed privily in Paris.
Wherever they were spent, these must have been months of hard work, as
were the years that followed. His time was now come. The long
preparation and training, bought by privation and uncongenial toil, was
over, and he was ready to apply himself to the scientific study of
sacred letters. His English patrons were liberal. Fisher sent him in
August 1511 to teach in Cambridge; Warham gave him a benefice, Aldington
in Kent, worth _L_33, 6_s._ 8_d._ a year, and in violation of his own
rule commuted it for a pension of L20 charged on the living; and the
dedications of his books were fruitful. In Cambridge he completed his
work on the New Testament, the Letters of Jerome, and Seneca; and then
in 1514, when there seemed no prospect of ampler preferment, he
determined to transfer himself to Basel and give the results of his
labours to the world.
The origin of Erasmus's connexion with Johann Froben is not clear. In
1511 he was preparing to reprint his _Adagia_ with Jodocus Badius, who
in the following year was to have also Seneca and Jerome. But in 1513
Froben, who had just reprinted the Aldine _Adagia_, acquired through a
bookseller-agent Erasmus' amended copy which had been destined for
Badius. That the agent was acting entirely on his own responsibility may
be doubted; for within a few months Erasmus had decided to betake
himself to Basel, bearing with him Seneca and Jerome, the latter to be
incorporated in the great edition which Johannes Amerbach and Froben had
had in hand since 1510. In Germany he was widely welcomed. The
Strassburg Literary Society feted him, and Johannes Sapidus, headmaster
of the Latin school at Schlettstadt, rode with him into Basel. Froben
received him with open arms, and the presses were soon busy with his
books. Through the winter of 1514-1515 Erasmus worked with the strength
of ten; and after a brief visit to England in the spring, the New
Testament was set up. Around him was a circle of students, some young,
some already distinguished--the three sons of Froben's partner, Johannes
Amerbach, who was now dead, Beatus Rhenanus, Wilhelm Nesen, Ludwig Ber,
Heinrich Glareanus, Nikolaus Gerbell, Johannes Oecolampadius--who looked
to him as their head and were proud to do him service.