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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 See also:

TERM

term usually denotes the unit in which the performance of See also:

steam and other engines is expressed, and which is defined as the See also:

RATE

rate at which See also:

WORK

work is done when 33,000 lb are raised one See also:

FOOT

foot in one See also:

minute. This value was adopted by See also:

James See also:

WATT, JAMES (1736-1819)

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 See also:

AVERAGE

average horse over a full See also:

day's work. It is equal to 746 See also:

watts. On the metric See also:

SYSTEM

system it is reckoned as 4500 kilogram-metres a minute, and the See also:

French cheval-vapeur is thus equal to 32,549 foot-pounds a minute, or o-9863 of an See also:

ENGLISH

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 See also:

ORDINARY (med. Lat. ordinarius, Fr. ordinaire)

ordinary See also:

formula for obtaining it is T- s-D2:/ S for high-pressure engines, and .117D2 y" S for condensing engines, where D is the See also:

DIAMETER (from the Cr. &a, through, µErpov, measure)

diameter of the See also:

PISTON (through Fr. from Ital. pistone or pestone, a great pestle, from Late Lat. pistare, to pound, a frequentative form of classical Lat. pinsere)

piston in inches and S the length of the stroke in feet, though varying See also:

numbers are used for the divisor. The " indicated horse-power " of a reciprocating See also:

engine is given by ASPN/ 33,000, where A is the See also:

AREA

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 See also:

CRANK

crank See also:

shaft if the engine is single-acting, but twice as many if it is See also:

double-acting. The mean pressure P is ascertained from the See also:

DIAGRAM

diagram or "card " given by an See also:

INDICATOR (from Lat. indicare, to point out)

indicator (see STEAM-ENGINE). In See also:

TURBINE (Lat. turbo, a whirlwind, a whirling motion ,or object, a top)

turbine engines this method is inapplicable. A statement of indicated horse-power supplies a measure of the force acting in the See also:

CYLINDER (Gr. KvAwSpos, from KvXivaety, to roll)

cylinder of an engine, but the power available for doing See also:

EXTERNAL

external work off the crank-shaft is less than this by the amount absorbed in See also:

DRIVING (from " to drive," i.e. generally to propel, force along or in, a word common in various forms to the Teutonic languages)

driving the engine itself. The useful See also:

RESIDUE (through the French, from the Lat. residuum, a remainder, from residere, to remain)

residue, known as the " actual," " effective " or " See also:

BRAKE

brake " horse-power, can be directly measured by a See also:

DYNAMOMETER (Gr. Suva u , strength, and OTpov, a measure)

dynamometer (q.v.); it amounts to about 8o% of the indicated horse-power for See also:

GOOD, JOHN MASON (1764-1827)

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 See also:

LAND

land practice, are directly coupled to See also:

electrical generators, their horse-power can be deduced from the electrical output. When they are used for the propulsion of See also:

SHIPS

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 See also:

SURFACE

surface of the shaft at different positions along it, and the relative displacement which occurs between them See also:

ROUND (O. Fr. rond, Lat. rotundus, the Fr. is the source also of Du. rond; Ger., Swed., Dan. and Nor. rond)

round the shaft when power is being transmitted is determined either by electrical means, as in the Denny-See also:

Johnson torsion-See also:

METER, ELECTRIC

meter, or optically, as in the See also:

Hopkinson-See also:

THRING, EDWARD (1821-1887)

Thring and Bevis-See also:

Gibson See also:

INSTRUMENTS

instruments. The twist or surface-shear being proportional to the See also:

TORQUE, or TORO (Lat. torquis, torques, a twisted collar, torquere, to twist)

torque, the horse-power can be calculated if the modulus of rigidity of the See also:

STEEL, FLORA ANNIE (1847– )

steel employed is known or if the amount of twist corresponding to a given power has previously been ascertained by See also:

DIRECT

direct experiment on the shaft before it has been put in See also:

PLACE (through Fr. from Lat. platea, street; Gr. IrAar6s, wide)

place. HORSE-RACING.

Probably the earliest instance of the use of horses in racing recorded in literature occurs in Il. See also:

XXIII

xxiii. 212-650, where the various incidents of the See also:

CHARIOT (derived from an O. Fr. word, formed from char, a car)

chariot-See also:

RACE

race at the funeral See also:

GAMES, CLASSICAL

games held in See also:

HONOUR (Lat. honos or lwnor, honoris; in English the word was spelled with or without the u indifferently until the 17th century, but during the 18th century it became fashion-able to spell the word " honor "; Johnson's and Webster's Dictionaries stereoty

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 See also:

early as the 23rd See also:

OLYMPIAD

Olympiad; to this the race with mounted horses was added in the 33rd; while other See also:

variations (such as two-horse chariot-races, See also:

MULE (Lat. mulus)

mule races, loose-horse races, See also:

SPECIAL

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 See also:

LEFT

left in See also:

IGNORANCE (Lat. ignorantia, from ignorare, not to know); want of knowledge, a state of mind which in law has important consequences. A well-known legal maxim runs: ignorantia juris non excusat ("ignorance of the law does not excuse")

ignorance; but it is known that the equestrian candidates were required to enter their names and send their horses to Ells at least See also:

THIRTY

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 See also:

month. At all the other See also:

NATIONAL

national games of See also:

GREECE

Greece (Pythian, Isthmian, Nemean), as well as at many of the See also:

LOCAL

local festivals (the Athenian See also:

OLYMPIA

Olympia and See also:

PANATHENAEA

Panathenaea), similar contests had a prominent place. Some indication of the extent to which the See also:

PASSION (post-classical Lat. passio, formed from pati, passus, to suffer, endure)

passion for horse-racing was indulged in at See also:

Athens, for example, about the See also:

time of See also:

Aristophanes may be obtained from the See also:

SCENE (Fr. scene, Lat. scaena, Gr. oflvil, a tent or booth, a stage or scene)

scene with which The Clouds opens; while it is a significant fact that the Boeotians termed one of the months of their See also:

YEAR

year, corresponding to the Athenian Hecatombacon, Hippodromius (" Horse-race month "; see See also:

Plutarch, See also:

CAM (CAO), DIOGO (fl. 1480-1486)

Cam. 15). For the chariot-races and horse-races of the Greeks and See also:

Romans, see See also:

CIRCUS (Lat. circus, Gr. Kipeos or Kptxot, a ring or' circle; probably " circus " and " ring " are of the same origin)

CIRCUS and GAMES.

End of Article: HORSENS

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