Chapter III: American (9)

S 16. _On the Choice of the Thermal Unit._--So much uncertainty still prevails on this fundamental point that it cannot be passed over without reference. There are three possible kinds of unit, depending on the three fundamental methods already given: (1) the thermometric unit, or the thermal capacity of unit mass of a standard substance under given conditions of temperature and pressure on the scale of a standard thermometer. (2) The latent-heat unit, or the quantity of heat required to melt or vaporize unit mass of a standard substance under given conditions. This unit has the advantage of being independent of thermometry, but the applicability of these methods is limited to special cases, and the relation of the units to other units is difficult to determine. (3) The absolute or mechanical unit, the quantity of heat equivalent to a given quantity of mechanical or electrical energy. This can be very accurately realized, but is not so convenient as (1) for ordinary purposes.

In any case it is necessary to define a thermometric unit of class
(1). The standard substance must be a liquid. Water is always
selected, although some less volatile liquid, such as aniline or
mercury, would possess many advantages. With regard to the scale of
temperature, there is very general agreement that the absolute scale
as realized by the hydrogen or helium thermometer should be adopted as
the ultimate standard of reference. But as the hydrogen thermometer is
not directly available for the majority of experiments, it is
necessary to use a secondary standard for the practical definition of
the unit. The electrical resistance thermometer of platinum presents
very great advantages for this purpose over the mercury thermometer in
point of reproducibility, accuracy and adaptability to the practical
conditions of experiment. The conditions of use of a mercury
thermometer in a calorimetric experiment are necessarily different
from those under which its corrections are determined, and this
difference must inevitably give rise to constant errors in practical
work. The primary consideration in the definition of a unit is to
select that method which permits the highest order of accuracy in
comparison and verification. For this reason the definition of the
thermal unit will in the end probably be referred to a scale of
temperature defined in terms of a standard platinum thermometer.

There is more diversity of opinion with regard to the question of the
standard temperature. Many authors, adopting Regnault's formula, have
selected 0 deg. C. as the standard temperature, but this cannot be
practically realized in the case of water, and his formula is
certainly erroneous at low temperatures. A favourite temperature to
select is 4 deg. C., the temperature of maximum density, since at this
point the specific heat at constant volume is the same as that at
constant pressure But this is really of no consequence, since the
specific heat at constant volume cannot be practically realized. The
specific heat at 4 deg. could be accurately determined at the mean
over the range 0 deg. to 8 deg. keeping the jacket at 0 deg. C. But
the change appears to be rather rapid near 0 deg., the temperature is
inconveniently low for ordinary calorimetric work, and the unit at 4
deg. would be so much larger than the specific heat at ordinary
temperatures that nearly all experiments would require reduction. The
natural point to select would be that of minimum specific heat, but if
this occurs at 40 deg. C. it would be inconveniently high for
practical realization except by the continuous electrical method. It
was proposed by a committee of the British Association to select the
temperature at which the specific heat was 4.200 joules, leaving the
exact temperature to be subsequently determined. It was supposed at
the time, from the original reduction of Rowland's experiments, that
this would be nearly at 10 deg. C., but it now appears that it may be
as low is 5 deg. C., which would be inconvenient. This is really only
an absolute unit in disguise, and evades the essential point, which is
the selection of a standard temperature for the water thermometric
unit. A similar objection applies to selecting the temperature at
which the specific heat is equal to its mean value between 0 deg. and
100 deg. The mean calorie cannot be accurately realized in practice
in any simple manner, and is therefore unsuitable as a standard of
comparison. Its relation to the calorie at any given temperature, such
as 15 deg. or 20 deg., cannot be determined with the same degree of
accuracy as the ratio of the specific heat at 15 deg. to that at 20
deg., if the scale of temperature is given. The most practical unit is
the calorie at 15 deg. or 20 deg. or some temperature in the range of
ordinary practice. The temperature most generally favoured is 15 deg.,
but 20 deg. would be more suitable for accurate work. These units
differ only by 11 parts in 10,000 according to Callendar and Barnes,
or by 13 in 10,000 according to Rowland and Griffiths, so that the
difference between them is of no great importance for ordinary
purposes. But for purposes of definition it would be necessary to take
the mean value of the specific heat _over a given range_ of
temperature, preferably at least 10 deg., rather than the specific
heat _at a point_ which necessitates reference to some formula of
reduction for the rate of variation. The specific heat at 15 deg.
would be determined with reference to the mean over the range 10 deg.
to 20 deg., and that at 20 deg. from the range 15 deg. to 25 deg.
There can be no doubt that the range 10 deg. to 20 deg. is too low for
the accurate thermal regulation of the conditions of the experiment.
The range 15 deg. to 25 deg. would be much more convenient from this
point of view, and a mean temperature of 20 deg. is probably nearest
the average of accurate calorimetric work. For instance 20 deg. is the
mean of the range of the experiments of Griffiths and of Rowland, and
is close to that of Schuster and Gannon. It is readily attainable at
any time in a modern laboratory with adequate heating arrangements,
and is probably on the whole the most suitable temperature to select.

S 17. _Specific Heat of Gases._--In the case of solids and liquids under ordinary conditions of pressure, the external work of expansion is so small that it may generally be neglected; but with gases or vapours, or with liquids near the critical point, the external work becomes so large that it is essential to specify the conditions under which the specific heat is measured. The most important cases are, the specific heats (1) at constant volume; (2) at constant pressure; (3) at saturation pressure in the case of a liquid or vapour. In consequence of the small thermal capacity of gases and vapours per unit volume at ordinary pressures, the difficulties of direct measurement are almost insuperable except in case (2). Thus the direct experimental evidence is somewhat meagre and conflicting, but the question of the relation of the specific heats of gases is one of great interest in connexion with the kinetic theory and the constitution of the molecule. The well-known experiments of Regnault and Wiedemann on the specific heat of gases at constant pressure agree in showing that the _molecular specific heat_, or the thermal capacity of the molecular weight in grammes, is approximately independent of the temperature and pressure in case of the more stable diatomic gases, such as H2, O2, N2, CO, &c., and has nearly the same value for each gas. They also indicate that it is much larger, and increases considerably with rise of temperature, in the case of more condensible vapours, such as Cl2, Br2, or more complicated molecules, such as CO2, N2O, NH3, C2H4. The direct determination of the specific heat at constant volume is extremely difficult, but has been successfully attempted by Joly with his steam calorimeter, in the case of air and CO2. Employing pressures between 7 and 27 atmospheres, he found that the specific heat of air between 10 deg. and 100 deg. C. increased very slightly with increase of density, but that of CO2 increased nearly 3% between 7 and 21 atmospheres. The following formulae represent his results for the specific heat s at constant volume in terms of the density d in gms. per c. c.:--

Air, s = 0.1715 + 0.028d,

CO2, s = 0.165 + 0.213d + 0.34d^2.

S 18. _Ratio of Specific Heats._--According to the elementary kinetic
theory of an ideal gas, the molecules of which are so small and so far
apart that their mutual actions may be neglected, the kinetic energy
of translation of the molecules is proportional to the absolute
temperature, and is equal to 3/2 of pv, the product of the pressure
and the volume, per unit mass. The expansion per degree at constant
pressure is v/[theta] = R/p. The external work of expansion per degree
is equal to R, being the product of the pressure and the expansion,
and represents the difference of the specific heats S - s, at constant
pressure and volume, assuming as above that the internal work of
expansion is negligible. If the molecules are supposed to be like
smooth, hard, elastic spheres, incapable of receiving any other kind
of energy except that of translation, the specific heat at constant
volume would be the increase per degree of the kinetic energy namely
3pv/2[theta] - 3R/2, that at constant pressure would be 5R/2, and the
ratio of the specific heats would be 5/3 or 1.666. This appears to be
actually the case for monatomic gases such as mercury vapour (Kundt
and Warburg, 1876), argon and helium (Ramsay, 1896). For diatomic or
compound gases Clerk Maxwell supposed that the molecule would also
possess energy of rotation, and endeavoured to prove that in this case
the energy would be equally divided between the six degrees of
freedom, three of translation and three of rotation, if the molecule
were regarded as a rigid body incapable of vibration-energy. In this
case we should have s = 3R, S = 4R, S/s = 4/3 = 1.333. In 1879 Maxwell
considered it one of the greatest difficulties which the kinetic
theory had yet encountered, that in spite of the many other degrees of
freedom of vibration revealed by the spectroscope, the experimental
value of the ratio S/s was 1.40 for so many gases, instead of being
less than 4/3. Somewhat later L. Boltzmann suggested that a diatomic
molecule regarded as a rigid dumb-bell or figure of rotation, might
have only five effective degrees of freedom, since the energy of
rotation about the axis of symmetry could not be altered by collisions
between the molecules. The theoretical value of the ratio S/s in this
case would be the required 7/5. For a rigid molecule on this theory
the smallest value possible would be 4/3. Since much smaller values
are found for more complex molecules, we may suppose that, in these
cases, the energy of rotation of a polyatomic molecule may be greater
than its energy of translation, or else that heat is expended in
splitting up molecular aggregates, and increasing energy of vibration.
A hypothesis doubtfully attributed to Maxwell is that each additional
atom in the molecule is equivalent to two extra degrees of freedom.
From an m-atomic molecule we should then have S/s = 1 + 2/(2m + 1).
This gives a series of ratios 5/3, 7/5, 9/7, 11/9, &c., for 1, 2, 3,
4, &c., atoms in the molecule, values which fall within the limits of
experimental error in many cases. It is not at all clear, however,
that energy of vibration should bear a constant ratio to that of
translation, although this would probably be the case for rotation.
For the simpler gases, which are highly diathermanous and radiate
badly even at high temperature, the energy of vibration is probably
very small, except under the special conditions which produce
luminosity in flames and electric discharges. For such gases, assuming
a constant ratio of rotation to translation, the specific heat at low
pressures would be very nearly constant. For more complex molecules
the radiative and absorptive powers are known to be much greater. The
energy of vibration may be appreciable at ordinary temperatures, and
would probably increase more rapidly than that of translation with
rise of temperature, especially near a point of dissociation. This
would account for an increase of S, and a diminution of the ratio S/s,
with rise of temperature which apparently occurs in many vapours. The
experimental evidence, however, is somewhat conflicting, and further
investigations are very desirable on the variation of specific heat
with temperature. Given the specific heat as a function of the
temperature, its variation with pressure may be determined from the
characteristic equation of the gas. The direct methods of measuring
the ratio S/s, by the velocity of sound and by adiabatic expansion,
are sufficiently described in many text-books.

S 19. _Atomic and Molecular Heats._--The ideal atomic heat is the
thermal capacity of a gramme-atom in the ideal state of monatomic gas
at constant volume. This would be nearly three calories. For a
diatomic gas, the molecular heat would be nearly five calories, or the
atomic heat of a gas in the diatomic state would be 2.5. Estimated at
constant pressure the atomic heat would be 3.5. Some authors adopt 2.5
and some 3.5 for the ideal atomic heat. The atomic heat of a metal in
the solid state is in most cases larger than six calories at ordinary
temperatures. Considering the wide variations in the physical
condition and melting points, the comparatively close agreement of the
atomic heats of the metals at ordinary temperatures, known as Dulong
and Petit's Law, is very remarkable. The specific heats as a rule
increase with rise of temperature, in some cases, e.g. iron and
nickel, very rapidly. According to W.A. Tilden (_Phil. Trans._, 1900),
the atomic heats of pure nickel and cobalt, as determined from
experiments at the boiling-points of O2, and CO2, diminish so rapidly
at temperatures below 0 deg. C. as to suggest that they would reach
the value 2.42 at the absolute zero. This is the value of the minimum
of atomic heat calculated by Perry from diatomic hydrogen, but the
observations themselves might be equally well represented by taking
the imaginary limit 3, since the quantity actually observed is the
mean specific heat between 0 deg. and -182.5 deg. C. Subsequent
experiments on other metals at low temperatures did not indicate a
similar diminution of specific heat, so that it may be doubted whether
the atomic heats really approach the ideal value at the absolute zero.
No doubt there must be approximate relations between the atomic and
molecular heats of similar elements and compounds, but considering the
great variations of specific heat with temperature and physical state,
in alloys, mixtures or solutions, and in allotropic or other
modifications, it would be idle to expect that the specific heat of a
compound could be accurately deduced by any simple additive process
from that of its constituents.

AUTHORITIES.--Joule's _Scientific Papers_ (London, 1890); Ames and
Griffiths, _Reports to the International Congress_ (Paris, 1900), "On
the Mechanical Equivalent of Heat," and "On the Specific Heat of
Water"; Griffiths, _Thermal Measurement of Energy_ (Cambridge, 1901);
Callendar and Barnes, _Phil. Trans._ A, 1901, "On the Variation of the
Specific Heat of Water"; for combustion methods, see article
THERMOCHEMISTRY, and treatises by Thomsen, Pattison-Muir and
Berthelot; see also articles THERMODYNAMICS and VAPORIZATION.
(H. L. C.)

CALOVIUS, ABRAHAM (1612-1686), German Lutheran divine, was born at Mohrungen in east Prussia, on the 16th of April 1612. After studying at Konigsberg, in 1650 he was appointed professor of theology at Wittenberg, where he afterwards became general superintendent and primarius. He died on the 25th of February 1686. Calovius was the most noteworthy of the champions of Lutheran orthodoxy in the 17th century. He strongly opposed the Catholics, Calvinists and Socinians, attacked in particular the reconciliation policy or "syncretism" of Georg Calixtus (cf. the _Consensus repetitus fidei vere lutheranae_, 1665), and as a writer of polemics he had few equals. His chief dogmatic work, _Systema locorum theologicorum_ (12 vols. 1655-1677), represents the climax of Lutheran scholasticism. In his _Biblia Illustrata_ (4 vols.), written from the point of view of a very strict belief in inspiration, his object is to refute the statements made by Hugo Grotius in his Commentaries. His _Historia Syncretistica_ (1682) was suppressed.

CALPURNIUS, TITUS, Roman bucolic poet, surnamed SICULUS from his birthplace or from his imitation of the style of the Sicilian Theocritus, most probably flourished during the reign of Nero. Eleven eclogues have been handed down to us under his name, of which the last four, from metrical considerations and express MS. testimony, are now generally attributed to Nemesianus (q.v.), who lived in the time of the emperor Carus and his sons (latter half of the 3rd century A.D.). Hardly anything is known of the life of Calpurnius; we gather from the poems themselves (in which he is obviously represented by "Corydon") that he was in poor circumstances and was on the point of emigrating to Spain, when "Meliboeus" came to his aid. Through his influence Calpurnius apparently secured a post at Rome. The time at which Calpurnius lived has been much discussed, but all the indications seem to point to the time of Nero. The emperor is described as a handsome youth, like Mars and Apollo, whose accession marks the beginning of a new golden age, prognosticated by the appearance of a comet, doubtless the same that appeared some time before the death of Claudius; he exhibits splendid games in the amphitheatre (probably the wooden amphitheatre erected by Nero in 57); and in the words

maternis causam qui vicit Iulis[1] (i. 45),

there is a reference to the speech delivered in Greek by Nero on behalf of the Ilienses (Suetonius, _Nero_, 7; Tacitus, _Annals_, xii. 58), from whom the Julii derived their family.[2] Meliboeus, the poet's patron, has been variously identified with Columella, Seneca the philosopher, and C. Calpurnius Piso. Although the sphere of Meliboeus's literary activity (as indicated in iv. 53) suits none of these, what is known of Calpurnius Piso fits in well with what is said of Meliboeus by the poet, who speaks of his generosity, his intimacy with the emperor, and his interest in tragic poetry. His claim is further supported by the poem _De Laude Pisonis_ (ed. C.F. Weber, 1859) which has come down to us without the name of the author, but which there is considerable reason for attributing to Calpurnius.[3] The poem exhibits a striking similarity with the eclogues in metre, language and subject-matter. The author of the _Laus_ is young, of respectable family and desirous of gaining the favour of Piso as his Maecenas. Further, the similarity between the two names can hardly be accidental; it is suggested that the poet may have been adopted by the courtier, or that he was the son of a freedman of Piso. The attitude of the author of the _Laus_ towards the subject of the panegyric seems to show less intimacy than the relations between Corydon and Meliboeus in the eclogues, and there is internal evidence that the _Laus_ was written during the reign of Claudius (Teuffel-Schwabe, _Hist, of Rom. Lit._ S 306, 6).

Mention may here be made of the fragments of two short hexameter poems in an Einsiedeln MS., obviously belonging to the time of Nero, which if not written by Calpurnius, were imitated from him.

Although there is nothing original in Calpurnius, he is "a skilful literary craftsman." Of his models the chief is Virgil, of whom (under the name of Tityrus) he speaks with great enthusiasm; he is also indebted to Ovid and Theocritus. Calpurnius is "a fair scholar, and an apt courtier, and not devoid of real poetical feeling. The bastard style of pastoral cultivated by him, in which the description of nature is made the writer's pretext, while ingenious flattery is his real purpose, nevertheless excludes genuine pleasure, and consequently genuine poetical achievement. He may be fairly compared to the minor poets of the reign of Anne" (Garnett).

Calpurnius was first printed in 1471, together with Silius Italicus
and has been frequently republished, generally with Gratius Faliscus
and Nemesianus. The separate authorship of the eclogues of Calpurnius
and Nemesianus was established by M. Haupt's _De Carminibus bucolicis
Calpurnii et Nemesiani_ (1854). Editions by H. Schenkl (1885), with
full introduction and _index verborum_, and by C.H. Keene (1887), with
introduction, commentary and appendix. English verse translation by
E.J.L. Scott (1891); see H.E. Butler, _Post-Augustan Poetry_ (Oxford,
1909), pp. 150 foil., and F. Skutsch in Pauly-Wissowa's
_Realencyclopadie_, iii. 1 (1897). (J. H. F.)

FOOTNOTES:

[1] _Iulis_ for _in ulnis_ according to the best MS. tradition.

[2] According to Dr R. Garnett (and Mr Greswell, as stated in
Conington's _Virgil_, i. p. 123, note) the emperor referred to is the
younger Gordian (A.D. 238). His arguments in favour of this will be
found in the article on Calpurnius by him in the 9th edition of the
_Encyclopaedia Britannica_ and in the _Journal of Philology_, xvi.,
1888; see in answer J.P. Postgate, "The Comet of Calpurnius Siculus"
in _Classical Review_, June 1902. Dean Merivale (_Hist. of the Romans
under the Empire_, ch. 60) and Pompei, "Intorno al Tempo del Poeta
Calpurnio" in _Atti del Istituto Veneto_, v. 6 (1880), identify the
amphitheatre with the Colosseum (Flavian amphitheatre) and assign
Calpurnius to the reign of Domitian.

[3] It has been variously ascribed to Virgil, Ovid, Lucan, Statius
and Saleius Bassus.

CALTAGIRONE, a city and episcopal see of the province of Catania, Sicily, situated 1999 ft. above sea-level, 36 m. S.W. of Catania direct (55 m. by rail). Pop. (1881) 25,978; (1901) town 35,116; commune 45,956. It is well built, and is said to be the most civilized provincial town in Sicily. Extensive Sicel cemeteries have been explored to the north of the town (_Not. Scavi_, 1904, 65), and a Greek necropolis of the 6th and 5th centuries B.C. has been found to the south-east (_ibid._ 132). Remains of buildings of Roman date have also been discovered; but the name of the ancient city which stood here is unknown. The present name is a corruption of the Saracen _Kalat-al-Girche_ (the castle of Girche, the chieftain who fortified it).

CALTANISETTA, a town and episcopal see of Sicily, the capital of a province of the same name, 60 m. S.E. of Palermo direct and 83 m. by rail, situated 1930 ft. above sea-level. Pop. (1901) 43,303. The town is of Saracenic origin, as its name _Kalat-al-Nisa_, the "Ladies' Castle," indicates, and some ruins of the old castle (called _Pietrarossa_) still exist. Otherwise the town contains no buildings of artistic or historical interest, but it commands striking views. It is the centre of the Sicilian sulphur industry and the seat of a royal school of mines. Two miles east is the interesting Norman abbey of S. Spirito.

CALTROP (from the Mid. Eng. _calketrappe_, probably derived from the Lat. _calx_, a heel, and _trappa_, Late Lat. for a snare), an iron ball, used as an obstacle against cavalry, with four spikes so arranged, that however placed in or on the ground, one spike always points upwards. It is also the botanical name for several species of thistles.

CALUIRE-ET-CUIRE, a town of eastern France, in the department of Rhone, 2-1/2 m. N. by E. of Lyons by rail. Pop. (1906) 9255. It has manufactures of coarse earthenware and hard-ware, copper and bronze foundries and nursery-gardens.

CALUMET (Norm. Fr. form of _chalumet_, from Lat. _calamus_, a reed), the name given by the French in Canada to the "peace-pipe" of the American Indians. This pipe occupied among the tribes a position of peculiar symbolic significance, and was the object of profound veneration. It was smoked on all ceremonial occasions, even on declarations of war, but its special use was at the making of treaties of peace. It was usually about 2-1/2 ft. long, and in the west the bowl was made of red pipes tone (catlinite), a fine-grained, easily-worked stone of a rich red colour found chiefly in the Coteau des Prairies west of Big Stone Lake, Dakota. The quarries were formerly neutral ground among the warring Indian tribes, many sacred traditions being associated with the locality and its product (Longfellow, _Hiawatha_, i.). The pipe stem was of reed decorated with eagles' quills or women's hair. Native tobacco mixed with willow-bark or sumac leaves was smoked. The pipe was offered as a supreme proof of hospitality to distinguished strangers, and its refusal was regarded as a grievous affront. In the east and south-east, the bowl was of white stone, sometimes pierced with several stem holes so that many persons might smoke at once.

See Joseph D. Macguire (exhaustive report,640 pages), "Pipes and
Smoking Customs of the American Aborigines" in _Smithsonian Report_
(American Bureau of Ethnology) for 1897, vol. i.; and authorities
quoted in _Handbook of American Indians_ (Washington, 1907).

CALUMPIT, a town of the province of Bulacan, Luzon, Philippine Islands, at the junction of the Quingua river with the Rio Grande de la Pampanga, about 25 m. N.W. of Manila. Pop. (1903) 13,897. It is served by the Manila & Dagupan railway, and the bridge across the Rio Grande is one of the longest in the Philippines. The surrounding country is a fertile plain, producing large quantities of rice, as well as sugar, Indian corn and a variety of fruits. Calumpit has a large rice-mill and one of the largest markets in the Philippines. The bridge, convent and church of the town were fired and completely destroyed by insurgent troops in 1899. The language is Tagalog.

CALVADOS, a department of north-western France, formed in 1790 out of Bessin, Cinglais, Hiemois, Bocage, the Campagne de Caen, Auge and the western part of Lieuvin. Pop. (1906) 403,431. Area, 2197 sq. m. It received its name from a ledge of rocks, stretching along the coast for a distance of about 15 m. between the mouths of the rivers Orne and Vire. It is bounded N. by the English Channel, E. by the department of Eure, S. by that of Orne, W. by that of Manche. The Bocage, or south-western part of the department, is elevated, being crossed from south-east to north-west by the hills of Normandy, the highest of which is 1197 ft.; the rest of the surface is gently undulating, and consists of extensive valleys watered by numerous streams which fall into the English Channel. The coast, formed by cliffs, sandy beaches or reefs, is generally inaccessible, except at the mouths of the principal rivers, such as the Touques, the Dives, the Orne and the Vire, which are navigable at high tide for several miles inland. Trouville is the chief of the numerous coast resorts. The climate, though humid and variable, is healthy. The raising of cattle, sheep and horses is the mainstay of the agriculture of the department. Pasture is good and abundant in the east and north-west, and there is a large export trade in the butter, eggs and cheese (Camembert, Livarot, Pont l'Eveque) of these districts, carried on by Honfleur, Isigny and other ports. The plain of Caen is a great centre for horse breeding. Wheat, oats, barley, colza and potatoes are the chief crops. The orchards of Auge and Bessin produce a superior kind of cider, of which upwards of 40,000,000 gallons are made in the department; a large quantity of cider brandy (eau-de-vie de Calvados) is distilled. Poultry to a considerable amount is sent to the Paris markets, and there is a large output of honey and wax. The spinning and weaving of wool and cotton are the chief industries. Besides these, paper-mills, oil-mills, tanneries, saw-mills, shipbuilding yards, rope-works, dye-works, distilleries and bleach-fields, scattered throughout the department, give employment to a number of hands. There are productive iron-mines and building-stone, slate and lime are plentiful. Fisheries, chiefly of lobster, oyster (Courseulles), herring and mackerel, are prosecuted. Coal, timber, grain, salt-fish and cement are among the imports; exports include iron, dairy products and sand. Caen and Honfleur are the most important commercial ports. There is a canal 9 m. in length from Caen to Ouistreham on the coast. The department is served by the Ouest-Etat railway. It is divided into the six arrondissements (38 cantons, 763 communes) of Caen, Falaise, Bayeux, Vire, Lisieux and Pont l'Eveque. Caen, the capital, is the seat of a court of appeal and the centre of an _academie_ (educational division). The department forms the diocese of Bayeux, in the ecclesiastical province of Rouen, and belongs to the region of the III. army-corps. The other principal towns are Falaise, Lisieux, Conde-sur-Noireau, Vire, Honfleur and Trouville (q.v.).

Amongst the great number of medieval churches which the department possesses, the fine Gothic church of St. Pierre-sur-Dives is second in importance only to those of Lisieux and Bayeux; that of Norrey, a good example of the Norman-Gothic style, and that of Tour-en-Bessin, in which Romanesque and Gothic architecture are mingled, are of great interest. Fontaine-Henri has a fine chateau of the 15th and 16th centuries.

CALVART, DENIS (1540-1619), Flemish painter, was born at Antwerp. After studying landscape-painting for some time in his native city he went to Bologna, where he perfected himself in the anatomy of the human form under Prospero Fontana, and so completely lost the mannerism of Flemish art that his paintings appear to be the work of an Italian. From Bologna he went to Rome, where he assisted Lorenzo Sabbatini (1533-1577) in his works for the papal palace, and devoted much of his time to copying and studying the works of Raphael. He ultimately returned to Bologna and founded a school, of which the greatest ornaments are Guido and Domenichino. His works are especially admired for the power of grouping and colouring which they display.

CALVARY, the conventional English rendering of the _calvaria_ of the Vulgate, the Latin version of the Greek _[Greek: kranion]_, both meaning "skull" and representing the Hebrew Golgotha, the name given to the scene of Christ's crucifixion. The term "a Calvary" is applied to a sculptured representation of the Crucifixion, either inside a church, or adjoining one in the open air. There are many examples of the latter in France, Italy and Spain. Among the most important are the Sacro Monte (1486) at Varallo in Piedmont, and those at Guimiliau (1581), Plougastel (1602), St Thegonnec (1610), and Pleyben near Quimper (1670), in Brittany, all in good preservation.

CALVE EMMA (1864- ), Spanish operatic soprano, was born at Madrid, and trained in Paris, making her first important appearance in opera at Brussels in 1882. She sang mainly in Paris for some years, but in 1892 was first engaged at Covent Garden, London, and at once became famous as the most vivid Carmen (in Bizet's opera) of the day.

CALVERLEY, CHARLES STUART (1831-1884), English poet and wit, and the literary father of what may be called the university school of humour, was born at Martley in Worcestershire on the 22nd of December 1831. His father, the Rev. Henry Blayds, resumed in 1852 the old family name of Calverley, which his grandfather had exchanged for Blayds in 1807. It was as Charles Stuart Blayds that most of the son's university distinctions were attained. He went up to Balliol from Harrow in 1850, and was soon known in Oxford as the most daring and most high-spirited undergraduate of his time. He was a universal favourite, a delightful companion, a brilliant scholar and the playful enemy of all "dons." In 1851 he won the Chancellor's prize for Latin verse, and it is said that the entire exercise was written in an afternoon, when his friends had locked him into his rooms, declining to let him out till he had finished what they were confident would prove the prize poem. A year later he took his name off the books, to avoid the consequences of a college escapade, and migrated to Christ's College, Cambridge. Here he was again successful in Latin verse, and remains the unique example of an undergraduate who has won the Chancellor's prize at both universities. In 1856 he took second place in the first class in the Classical Tripos. He was elected fellow of Christ's (1858), published _Verses and Translations_ in 1862, and was called to the bar in 1865. Owing to an accident while skating he was prevented from following up a professional career, and during the last years of his life he was an invalid. His _Translations into English and Latin_ appeared in 1866; his _Theocritus translated into English Verse_ in 1869; _Fly Leaves_ in 1872; and _Literary Remains_ in 1885. He died on the 17th of February 1884. Calverley was one of the most brilliant men of his day; and, had he enjoyed health, might have achieved distinction in any career he chose. Constitutionally indolent, he was endowed with singular gifts in every department of culture; he was a scholar, a musician, an athlete and a brilliant talker. What is left us marks only a small portion of his talent, but his sparkling, dancing verses, which have had many clever imitators, are still without a rival in their own line. His humour was illumined by good nature; his satire was keen but kind; his laughter was of that human sort which is often on the verge of tears. Imbued with the classical spirit, he introduced into the making of light verse the polish and elegance of the great masters, and even in its most whimsical mood his verse is raised to the level of poetry by the saving excellence of style.

His _Complete Works_, with a biographical notice by Sir W.J. Sendall,
appeared in 1901. (A. Wa.)

CALVERT, the name of three English artists: Charles (1785-1852), a well-known landscape-painter; Edward (1803-1883), an important wood-engraver and follower of Blake; and Frederick, an excellent topographical draughtsman, whose work in water-colour is represented at the Victoria and Albert Museum, and who published a volume of _Picturesque Views in Staffordshire and Shropshire_ (1830).

CALVERT, FREDERICK CRACE (1819-1873), English chemist, was born in London on the 14th of November 1819. From about 1836 till 1846 he lived in France, where, after a course of study at Paris, he became manager of some chemical works, later acting as assistant to M.E. Chevreul. On his return to England he settled in Manchester as a consulting chemist, and was appointed professor of chemistry at the Royal Institution in that city. Devoting himself almost entirely to industrial chemistry, he gave much attention to the manufacture of coal-tar products, and particularly carbolic acid, for the production of which he established large works in Manchester in 1865. Besides contributing extensively to the English and French scientific journals, he published a work on _Dyeing and Calico-Printing._ He died in Manchester on the 24th of October 1873.

CALVERT, SIR HARRY, BART. (c. 1763-1826), British general, was probably born early in 1763 at Hampton, near London. He was educated at Harrow, and at the age of fifteen entered the army. In the following year he served with his regiment in America, being present at the siege of Charleston, and serving through the campaign of Lord Cornwallis which ended with the surrender of Yorktown. From 1781 to 1783 he was a prisoner of war. Returning to England in 1784, he next saw active service in 1793-1794 in the Low Countries, where he was aide-de-camp to the duke of York, and in 1795 was engaged on a confidential mission to Brunswick and Berlin. In 1799, having already served as deputy adjutant general, he was made adjutant general, holding the post till 1818. In this capacity he effected many improvements in the organization and discipline of the service. He greatly improved the administration of the army medical and hospital department, introduced regimental schools, developed the two existing military colleges (since united at Sandhurst), and was largely responsible for the founding of the Duke of York's school, Chelsea. In recognition of his work as adjutant general he was made a G.C.B. (1815), and, on retiring from office, received a baronetcy (1818). In 1820 he was made governor of Chelsea hospital. He died on the 3rd of September 1826, at Middle Claydon, Buckinghamshire.

CALVES' HEAD CLUB, a club established shortly after his death in derision of the memory of Charles I. Its chief meeting was held on the 30th of each January, the anniversary of the king's execution, when the dishes served were a cod's head to represent the individual, Charles Stuart; a pike representing tyranny; a boar's head representing the king preying on his subjects; and calves' heads representing Charles as king and his adherents. On the table an axe held the place of honour. After the banquet a copy of the king's _Ikon Basilike_ was burnt, and the toast was "To those worthy patriots who killed the tyrant." After the Restoration the club met secretly. The first mention of it is in a tract reprinted in the _Harleian Miscellany_ entitled "The Secret History of the Calves' Head Club." The club survived till 1734, when the diners were mobbed owing to the popular ill-feeling which their outrages on good taste provoked, and the riot which ensued put a final stop to the meetings.

CALVI, a sea-port in Corsica, capital of an arrondissement in the N.W. of the island, 112 m. N. of Ajaccio by road. Pop. (1906) 1967. It is situated on the Bay of Calvi, in a malarial region, and is the port in Corsica nearest to France, being 109 m. from Antibes; the harbour, however, is exposed to the east and north-east winds. The modern town lies at the foot of a rock, on which stands the old town with its steep rock-paved streets and fortified walls, commanded by the Fort Muzello. Fishing is carried on, and timber, oil, wine, lemons and other sub-tropical fruits are exported to some extent. The most important buildings are the old palace of the Genoese governor, used as barracks, and the church (16th century), with the monument of the Baglioni family, which was intimately associated with the history of the town.

Calvi was founded in the 13th century and in 1278 passed into the hands of the Genoese. From that date it was remarkable for its adherence to their side, especially in 1553 when it repulsed two attacks of the united forces of the French and Turks. In recognition thereof the Genoese senate caused the words _Civitas Calvi semper fidelis_ to be carved on the chief gate of the city, which still preserves the inscription. In 1794 Calvi was captured by the English, but it was retaken by the Corsicans in the following year.

CALVIN, JOHN (1500-1564), Swiss divine and reformer, was born at Noyon, in Picardy, on the 10th of July 1509. His father, Gerard Cauvin or Calvin,[1] was a notary-apostolic and procurator-fiscal for the lordship of Noyon, besides holding certain ecclesiastical offices in connexion with that diocese. The name of his mother was Jeanne le Franc; she was the daughter of an innkeeper at Cambrai, who afterwards came to reside at Noyon. Gerard Cauvin was esteemed as a man of considerable sagacity and prudence, and his wife was a godly and attractive lady. She bore him five sons, of whom John was the second. By a second wife there were two daughters.

Of Calvin's early years only a few notices remain. His father destined him from the first for an ecclesiastical career, and paid for his education in the household of the noble family of Hangest de Montmor. In May 1521 he was appointed to a chaplaincy attached to the altar of La Gesine in the cathedral of Noyon, and received the tonsure. The actual duties of the office were in such cases carried out by ordained and older men for a fraction of the stipend. The plague having visited Noyon, the young Hangests were sent to Paris in August 1523, and Calvin accompanied them, being enabled to do so by the income received from his benefice. He lived with his uncle and attended as an out-student the College de la Marche, at that time under the regency of Mathurin Cordier, a man of character, learning and repute as a teacher, who in later days followed his pupil to Switzerland, taught at Neuchatel, and died in Geneva in 1564. In dedicating to him his _Commentary on the First Epistle to the Thessalonians_, as "eximiae pietatis et doctrinae viro," he declares that so had he been aided by his instruction that whatever subsequent progress he had made he only regarded as received from him, and "this," he adds, "I wish to testify to posterity that if any utility accrue to any from my writings they may acknowledge it as having in part flowed from thee." From the College de la Marche he removed to the College de Montaigu,[2] where the atmosphere was more ecclesiastical and where he had for instructor a Spaniard who is described as a man of learning and to whom Calvin was indebted for some sound training in dialectics and the scholastic philosophy. He speedily outstripped all his competitors in grammatical studies, and by his skill and acumen as a student of philosophy, and in the college disputations gave fruitful promise of that consummate excellence as a reasoner in the department of speculative truth which he afterwards displayed. Among his friends were the Hangests (especially Claude), Nicolas and Michel Cop, sons of the king's Swiss physician, and his own kinsman Pierre Robert, better known as Olivetan. Such friendships testify both to the worth and the attractiveness of his character, and contradict the old legend that he was an unsociable misanthrope. Pleased with his success, the canons at Noyon gave him the curacy of St Martin de Marteville in September 1527. After holding this preferment for nearly two years, he exchanged it in July 1529 for the cure of Pont L'Eveque, a village near to Noyon, and the place to which his father originally belonged. He appears to have been not a little elated by his early promotion, and although not ordained, he preached several sermons to the people. But though the career of ecclesiastical preferment was thus early opened to him, Calvin was destined not to become a priest. A change came over the mind both of his father and himself respecting his future career. Gerard Cauvin began to suspect that he had not chosen the most lucrative profession for his son, and that the law offered to a youth of his talents and industry a more promising sphere.[3] He was also now out of favour with the cathedral chapter at Noyon. It is said also that John himself, on the advice of his relative, Pierre Robert Olivetan, the first translator of the Bible into French, had begun to study the Scriptures and to dissent from the Roman worship. At any rate he readily complied with his father's suggestion, and removed from Paris to Orleans (March 1528) in order to study law under Pierre Taisan de l'Etoile, the most distinguished jurisconsult of his day. The university atmosphere here was less ascetic than at Paris, but Calvin's ardour knew no slackening, and such was his progress in legal knowledge that he was frequently called upon to lecture, in the absence of one or other of the regular staff. Other studies, however, besides those of law occupied him while in this city, and moved by the humanistic spirit of the age he eagerly developed his classical knowledge. "By protracted vigils," says Beza, "he secured indeed a solid erudition and an excellent memory; but it is probable he at the same time sowed the seeds of that disease (dyspepsia) which occasioned him various illnesses in after life, and at last brought upon him premature death."[4] His friends here were Melchior Wolmar, a German schoolmaster and a man of exemplary scholarship and character, Francois Daniel, Francois de Connam and Nicolas Duchemin; to these his earliest letters were written.

From Orleans Calvin went to Bourges in the autumn of 1529 to continue his studies under the brilliant Italian, Andrea Alciati (1492-1550), whom Francis I. had invited into France and settled as a professor of law in that university. His friend Daniel went with him, and Wolmar followed a year later. By Wolmar Calvin was taught Greek, and introduced to the study of the New Testament in the original, a service which he gratefully acknowledges in one of his printed works.[5] The conversation of Wolmar may also have been of use to him in his consideration of the doctrines of the Reformation, which were now beginning to be widely diffused through France. Twelve years had elapsed since Luther had published his theses against indulgences--twelve years of intense excitement and anxious discussion, not in Germany only, but in almost all the adjacent countries. In France there had not been as yet any overt revolt against the Church of Rome, but multitudes were in sympathy with any attempt to improve the church by education, by purer morals, by better preaching and by a return to the primitive and uncorrupted faith. Though we cannot with Beza regard Calvin at this time as a centre of Protestant activity, he may well have preached at Lignieres as a reformatory Catholic of the school of Erasmus. Calvin's own record of his "conversion" is so scanty and devoid of chronological data that it is extremely difficult to trace his religious development with any certainty. But it seems probable that at least up to 1532 he was far more concerned about classical scholarship than about religion.

His residence at Bourges was cut short by the death of his father in May 1531. Immediately after this event he went to Paris, where the "new learning" was now at length ousting the medieval scholasticism from the university. He lodged in the College Fortet, reading Greek with Pierre Danes and beginning Hebrew with Francois Vatable. It was at this time (April 1532) that Calvin issued his first publication, a commentary in Latin on Seneca's tract _De Clementia_. This book he published at his own cost, and dedicated to Claude Hangest, abbot of St Eloi, a member of the de Montmor family, with whom Calvin had been brought up. It was formerly thought that Calvin published this work with a view to influence the king to put a stop to the attacks on the Protestants, but there is nothing in the treatise itself or in the commentary to favour this opinion.

Soon after the publication of his first book Calvin returned to Orleans, where he stayed for a year, perhaps again reading law, and still undecided as to his life's work. He visited Noyon in August 1533, and by October of the same year was settled again in Paris. Here and now his destiny became certain. The conservative theology was becoming discredited, and humanists like Jacques Lefevre of Etaples (Faber Stapulensis) and Gerard Roussel were favoured by the court under the influence of Margaret of Angouleme, queen of Navarre and sister of Francis I. Calvin's old friend, Nicolas Cop, had just been elected rector of the university and had to deliver an oration according to custom in the church of the Mathurins, on the feast of All Saints. The oration (certainly influenced but hardly composed by Calvin) was in effect a defence of the reformed opinions, especially of the doctrine of justification by faith alone. It is to the period between April 1532 and November 1533, and in particular to the time of his second sojourn at Orleans, that we may most fittingly assign the great change in Calvin which he describes (_Praef. ad Psalmos_; opera xxxi. 21-24) as his "sudden conversion" and attributes to direct divine agency. It must have been at least after his _Commentary on Seneca's De Clementia_ that his heart was "so subdued and reduced to docility that in comparison with his zeal for true piety he regarded all other studies with indifference, though not entirely forsaking them. Though himself a beginner, many flocked to him to learn the pure doctrine, and he began to seek some hiding-place and means of withdrawal from people." This indeed was forced upon him, for Cop's address was more than the conservative party could bear, and Cop, being summoned to appear before the parlement of Paris, found it necessary, as he failed to secure the support either of the king, or of the university, to make his escape to Basel. An attempt was at the same time made to seize Calvin, but, being forewarned of the design by his friends, he also made his escape. His room in the College Fortet, however, was searched, and his books and papers seized, to the imminent peril of some of his friends, whose letters were found in his repositories. He went to Noyon, but, proceedings against him being dropped, soon returned to Paris. But desiring both security and solitude for study he left the city again about New Year of 1534 and became the guest of Louis du Tillet, a canon of the cathedral, at Angouleme, where at the request of his host he prepared some short discourses, which were circulated in the surrounding parishes, and read in public to the people. Here, too in du Tillet's splendid library, he began the studies which resulted in his great work, the _Institutes_, and paid a visit to Nerac, where the venerable Lefevre, whose revised translation of the Bible into French was published about this time, was spending his last years under the kindly care of Margaret of Navarre.

Calvin was now nearly twenty-five years of age, and in the ordinary way would have been ordained to the priesthood. Up till this time his work for the evangelical cause was not so much that of the public preacher or reformer as that of the retiring but influential scholar and adviser. Now, however, he had to decide whether, like Roussel and other of his friends, he should strive to combine the new doctrines with a position in the old church, or whether he should definitely break away from Rome. His mind was made up, and on the 4th of May he resigned his chaplaincy at Noyon and his rectorship at Pont l'Eveque. Towards the end of the same month he was arrested and suffered two short terms of imprisonment, the charges against him being not strong enough to be pressed. He seems to have gone next to Paris, staying perhaps with Etienne de la Forge, a Protestant merchant who suffered for his faith in February 1535. To this time belongs the story of the proposed meeting between Calvin and the Spanish reformer Servetus. Calvin's movements at this time are difficult to trace, but he visited both Orleans and Poitiers, and each visit marked a stage in his development.

The Anabaptists of Germany had spread into France, and were disseminating many wild and fanatical opinions among those who had seceded from the Church of Rome. Among other notions which they had imbibed was that of a sleep of the soul after death. To Calvin this notion appeared so pernicious that he composed a treatise in refutation of it, under the title of _Psychopannychia_. The preface to this treatise is dated Orleans 1534, but it was not printed till 1542. In it he chiefly dwells upon the evidence from Scripture in favour of the belief that the soul retains its intelligent consciousness after its separation from the body--passing by questions of philosophical speculation, as tending on such a subject only to minister to an idle curiosity. At Poitiers Calvin gathered round him a company of cultured and gentle men whom in private intercourse he influenced considerably. Here too in a grotto near the town he for the first time celebrated the communion in the Evangelical Church of France, using a piece of the rock as a table.

The year 1534 was thus decisive for Calvin. From this time forward his influence became supreme, and all who had accepted the reformed doctrines in France turned to him for counsel and instruction, attracted not only by his power as a teacher, but still more, perhaps because they saw in him so full a development of the Christian life according to the evangelical model. Renan, no prejudiced judge, pronounces him "the most Christian man of his time," and attributes to this his success as a reformer. Certain it is that already he had become conspicuous as a prophet of the new religion; his life was in danger, and he was obliged to seek safety in flight. In company with his friend Louis du Tillet, whom he had again gone to Angouleme to visit, he set out for Basel. On their way they were robbed by one of their servants, and it was only by borrowing ten crowns from their other servant that they were enabled to get to Strassburg, and thence to Basel. Here Calvin was welcomed by the band of scholars and theologians who had conspired to make that city the Athens of Switzerland, and especially by Oswald Myconius, the chief pastor, Pierre Viret and Heinrich Bullinger. Under the aupices and guidance of Sebastian Munster, Calvin now gave himself to the study of Hebrew.