[1] Compare Sans, _acva_, Zendish and Old Persian _acpa_, Lithuanian
_aszva_ (mare), Prussian _asvinan_ (mare's milk), O.H. Ger. _ehu_,
A.S. _eoh_, Icel. _ior_, Gothic _aihos_, _aihous_ (?), Old Irish
_ech_, Old Cambrian and Gaelic _ep_ (as in _Epona_, the horse
goddess), Lat. _equus_, Gr. [Greek: hippos] or [Greek: ikkos]. The
word seems, however, to have disappeared from the Slavonic languages.
The root is probably _ak_, with the idea of sharpness or swiftness
([Greek: akros, okus], _acus_, _ocior_). See Pott, _Etym. Forsch_,
ii. 256, and Hehn, _Kulturpflanzen u. Hausthiere in ihrem Ueber gang
aus Asien nach Griechenland u. Italien sowie in das ubrige Europa_
(3rd ed., 1877), p. 38. The last-named author, who points out the
absence of the horse from the Egyptian monuments prior to the
beginning of the 18th century B.C., and the fact that the earliest
references to this animal in Hebrew literature (Judges v. 22, 28; cf.
Josh, xi. 4) do not carry us any farther back, is of opinion that the
Semitic peoples as a whole were indebted for the horse to the lands
of Iran. He also shows that literature affords no trace of the horse
as indigenous to Arabia prior to about the beginning of the 5th
century A.D., although references abound in the pre-Islamitic poetry.
Horses were not numerous even in Mahomet's time (Sprenger, _Leb.
Moh._ iii. 139, 140). Compare Ignazio Guidi's paper "Della sede
primitiva dei popoli Semitici" in the _Transactions_ of the Accademia
dei Lincei (1878-1879), Professor W. Ridgeway, in his _Origin and
Influence of the Thoroughbred Horse_ (1905), reinvestigated the
historical mystery as to the Arab breed, and its connexion with the
English thoroughbred stock, but his conclusions have been hotly
controverted; archaeology and biology are in fact still in the dark
on the subject, but see the section on "Species" above. According to
Ridgeway, the original source of the finest equine blood is Africa,
still the home of the largest variety of wild Equidae; he concludes
that thence it passed into Europe at an early time, to be blended
with that of the indigenous Celtic species, and thence into western
Asia into the veins of an indigenous Mongolian species, still
represented by "Przewalski's horse"; not till a comparatively late
period did it reach Arabia, though the "Arab" now represents the
purest form of the Libyan blood. The controversy depends upon the
consideration of a wealth of detail, which should be studied in
Ridgeway's book; but zoological authorities are sceptical as to the
suggested species, _Equus caballus libycus_.
[2] Some fragments of legislation relating to the horse about this
period may be gleaned from _Ancient Laws and Institutes of England_
(fol., London, 1840), and _Ancient Laws and Institutes of Wales_
(fol., London, 1841).
HORSE LATITUDES, the belts of calms and variable breezes at the polar
edge of the N.E. and S.E. trades. According to the _New English
Dictionary_ two explanations have been given of the origin of the name:
one that the calm kills horses on a sailing ship, the other that the
name signifies the unruly and boisterous nature of these winds compared
with the pleasant trades. The name is commonly applied to the permanent
belt of high atmospheric pressure which encircles the globe in 30 deg.
to 35 deg. from the equator.
HORSE-MACKEREL, the name applied to a genus of fishes (_Caranx_) found
in abundance in almost all temperate and especially in tropical seas.
The designation "cavalli," given to them by the early Portuguese
navigators, and often met with in the accounts of the adventures of the
buccaneers, is still in frequent use among the sailors of all nations.
Some ninety different kinds are known--the majority being wholesome
food, and some of the species attaining a length of 3 ft. and more. The
fish to which the name horse-mackerel is applied in Great Britain is
_Caranx trachurus_, distinguished by having the lateral line in its
whole length armed with large but narrow bony plates. Horse-mackerel are
found singly on the coast all the year round, but sometimes they
congregate in shoals of many thousands. Although well-flavoured, they
are much more frequently used for bait than for food. This species has a
most extraordinary range, being found almost everywhere within the
temperate and tropical zones of the northern and southern hemispheres.
HORSEMANSHIP, the art of managing the horse from his back and
controlling his paces and the direction and speed of his movement. The
ordinary procedure is dealt with in the articles on RIDING and cognate
subjects (see also HORSE: section _Management_). A special kind of skill
is, however, needed in breaking, training, bitting and schooling horses
for a game like polo, or for the evolutions of what is known as the
_haute ecole_. It is with the latter, or "school" riding, that we deal
here. The middle ages had seen chivalry developed into a social
distinction, and horsemanship into a form of knightly prowess. The
Renaissance introduced the cultivation of horsemanship as an art, with
regular conditions and rules, instead of merely its skilful practice for
utility and exercise. In Italy in the 16th century schools of
horsemanship were established at Naples, Rome and other chief cities;
thither flocked the nobility of France, Spain and Germany; and Henry
VIII. of England and other monarchs of his time had Italians for their
masters of the horse. The academy of Pignatelli at Naples was the most
famous of the schools in the middle of the 16th century, but a score of
other less renowned masters devoted themselves to teaching the riders
and training the horses. Trappings of all sorts multiplied; the
prescribed tricks, feats and postures involved considerable dexterity;
they were fatiguing to both man and beast, and were really useless
except for show. This elaborate art, enthusiastically followed among the
Romance nations, was the parent of later developments of the _haute
ecole_, and of the circus-performances of modern days. In England,
however, the continental style did not find favour for long. The duke of
Newcastle's _Methode nouvelle de dresser les chevaux_ (1648) was the
leading text-book of the day, and in 1761 the earl of Pembroke published
his _Manual of Cavalry Horsemanship_. In France a simplification was
introduced in the early part of the 18th century by La Gueriniere
(_Ecole de cavalerie_) and others. The French military school thus
became the model for Europe, though the English style remained in
opposition, forming a sort of compromise with the ordinary method of
riding across country. In more modern times France again came to the
front in regard to the _haute ecole_, through the innovations of the
vicomte d'Aure (1798-1863) and Francois Baucher (1796-1873). Baucher was
a circus-rider who became the greatest master of his art, and who had an
elaborate theory of the principles involved in training a horse. His
system was carried on, with modifications, by masters and theorists like
Captain Raabe, M. Barroil and M. Fillis. In more recent times the style
of the _haute ecole_ has also been cultivated by various masters in the
United States, such as H. L. de Bussigny at Boston.
See d'Aure, _Traite d'equitation_ (1847); Hundersdorf, _Equitation
allemande_ (Bruxelles, 1843); Baucher, _Passe-temps equestres_ (1840),
_Methode d'equitation_ (1867); Raabe, _Methode de haute ecole
d'equitation_ (1863); Barroil, _Art equestre_; Fillis, _Principes de
dressage_; Hayes, _Riding on the flat, &c._ (1882).
HORSENS, a market town of Denmark, at the head of Horsens Fjord, on the
east side of Jutland, 32 m. by rail S.W. of Aarhus, in the _amt_
(county) of that name. Pop. (1901) 22,243. It is the junction of branch
railways to Bryrup and to Torring inland, and to Juelsminde on the
coast. The exports are chiefly bacon and butter; the imports, iron,
yarn, coal and timber. The town is ancient; there is a disused convent
church with tombs of the 17th century, and the Vor-Frelsers-Kirke has a
carved pulpit of the same period. Horsens is the birthplace of the
navigator Vitus Bering or Behring (1680), the Arctic explorer. To the
north lies the picturesque lake district between Skanderborg and
Silkeborg (see AARHUS).
HORSE-POWER. The device, frequently seen in farmyards, by which the
power of a horse is utilized to drive threshing or other machinery, is
sometimes described as a "horse-power," but this term usually denotes
the unit in which the performance of steam and other engines is
expressed, and which is defined as the rate at which work is done when
33,000 lb. are raised one foot in one minute. This value was adopted by
James Watt as the result of experiments with strong dray-horses, but, as
he was aware, it is in excess of what can be done by an average horse
over a full day's work. It is equal to 746 watts. On the metric system
it is reckoned as 4500 kilogram-metres a minute, and the French
_cheval-vapeur_ is thus equal to 32,549 foot-pounds a minute, or 0.9863
of an English horse-power, or 736 watts. The "nominal horse-power" by
which engines are sometimes rated is an arbitrary and obsolescent term
of indefinite significance. An ordinary formula for obtaining it is
(1/15.6)D^2 [root 3]S for high-pressure engines, and (1/47)D^2 [root 3]S
for condensing engines, where D is the diameter of the piston in inches
and S the length of the stroke in feet, though varying numbers are used
for the divisor. The "indicated horse-power" of a reciprocating engine
is given by ASPN/33,000, where A is the area of the piston in square
inches, S the length of the stroke in feet, P the mean pressure on the
piston in lb. per sq. in., and N the number of effective strokes per
minute, namely, one for each revolution of the crank shaft if the engine
is single-acting, but twice as many if it is double-acting. The mean
pressure P is ascertained from the diagram or "card" given by an
indicator (see STEAM-ENGINE). In turbine engines this method is
inapplicable. A statement of indicated horse-power supplies a measure of
the force acting in the cylinder of an engine, but the power available
for doing external work off the crank-shaft is less than this by the
amount absorbed in driving the engine itself. The useful residue, known
as the "actual," "effective" or "brake" horse-power, can be directly
measured by a dynamometer (q.v.); it amounts to about 80% of the
indicated horse-power for good condensing engines and about 85% for
non-condensing engines, or perhaps a little more when the engines are of
the largest sizes. When turbines, as often happens in land practice, are
directly coupled to electrical generators, their horse-power can be
deduced from the electrical output. When they are used for the
propulsion of ships recourse is had to "torsion meters" which measure
the amount of twist undergone by the propeller shafts while transmitting
power. Two points are selected on the surface of the shaft at different
positions along it, and the relative displacement which occurs between
them round the shaft when power is being transmitted is determined
either by electrical means, as in the Denny-Johnson torsion-meter, or
optically, as in the Hopkinson-Thring and Bevis-Gibson instruments. The
twist or surface-shear being proportional to the torque, the horse-power
can be calculated if the modulus of rigidity of the steel employed is
known or if the amount of twist corresponding to a given power has
previously been ascertained by direct experiment on the shaft before it
has been put in place.
HORSE-RACING. Probably the earliest instance of the use of horses in
racing recorded in literature occurs in _Il._ xxiii. 212-650, where the
various incidents of the chariot-race at the funeral games held in
honour of Patroclus are detailed with much vividness. According to the
ancient authorities the four-horse chariot-race was introduced into the
Olympic games as early as the 23rd Olympiad; to this the race with
mounted horses was added in the 33rd; while other variations (such as
two-horse chariot-races, mule races, loose-horse races, special races
for under-aged horses) were admitted at a still later period. Of the
training and management of the Olympic race-horse we are left in
ignorance; but it is known that the equestrian candidates were required
to enter their names and send their horses to Elis at least thirty days
before the celebration of the games commenced, and that the charioteers
and riders, whether owners or proxies, went through a prescribed course
of exercise during the intervening month. At all the other national
games of Greece (Pythian, Isthmian, Nemean), as well as at many of the
local festivals (the Athenian Olympia and Panathenaea), similar contests
had a prominent place. Some indication of the extent to which the
passion for horse-racing was indulged in at Athens, for example, about
the time of Aristophanes may be obtained from the scene with which _The
Clouds_ opens; while it is a significant fact that the Boeotians termed
one of the months of their year, corresponding to the Athenian
Hecatombaeon, Hippodromius ("Horse-race month"; see Plutarch, _Cam._
15). For the chariot-races and horse-races of the Greeks and Romans, see
CIRCUS and GAMES.