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8. Thus radiation is one phenomenon, and (as we shall of heat; and we must also introduce some results of the find) the spectrum of a black body (a conception roughly splendid investigations of Sadi Carnot (1824), which cast realized in the carbon poles of an electric lamp) is continu an entirely new light on the whole subject of heat. ous from the longest possible wave-length to the shortest 11. Prévost's leading idea was that all bodies, whether which it is hot enough to emit. These various groups of cold or hot, are constantly radiating heat. This of itself rays, however, are perceived by us in very

different ways, was a very great step. It is distinctly enunciated in the whether by direct impressions of sense or by the different term "exchange' which he employs. And from the way modes in which they effect physical changes or transforma in which he introduces it it is obvious that he means tions. The only way as yet known to us of treating them (though he does not expressly say so) that the radiation all alike is to convert their energy into the heat-form and from a body depends on its own nature and temperature measure it as such. This we can do in a satisfactory alone, and is independent altogether of the nature and manner by the thermo-electric pile and galvanometer. temperature of any adjacent body. This also was a step 9. Of the history of the gradual development of the in advance

, and of the utmost value. It will be seen later theory of radiation we can give only the main features. that Prévost was altogether wrong in his assumption of The apparent concentration of cold by a concave mirror, the geometrical rate of adjustment of differences of which had been long before observed by Porta, was redis- temperature,—a statement originally made by Newton, covered by Pictet, and led to the extremely important but true only approximately, and even so for very small enunciation of the Law of Exchanges by Prévost in 1791. temperature differences alone. Newton in the Queries to As we have already seen, Prévost's idea of the nature of the third book of his Optics distinctly recognizes the proradiation was a corpuscular one, no doubt greatly influenced pagation of heat from a hot body to a cold one by the in this direction by the speculations of Lesage (see ATOM). vibrations of an intervening medium. But he says noBut the value of his theory as a concise statement of thing as to bodies of the same temperature. facts and a mode of co-ordinating them is not thereby 12. To Carnot we owe the proposition that the thermal materially lessened. We give his own statements in the motivity of a system cannot be increased by internal actions. following close paraphrase, in which the italics are re A system in which all the parts are at the same temperatained, from sect. ix. of his Du Calorique Rayonnant ture has no thermal motivity, for bodies at different (Geneva, 1809).

temperatures are required in order to work a heat-engine, “1. Free caloric is a radiant fluid. And because caloric becomes so as to convert part of their heat into work. Hence, if free at the surfaces of bodies every point of the surface of a body is the contents of an enclosure which is impervious to heat a centre, towards and from which filaments (filets) of caloric move

are at any instant at one and the same temperature, no in all directions.

This 2. Heat equilibrium between two neighbouring free spaces changes of temperature can take place among them. consists in cquality of exchange.

is certainly true so far as our modes of measurement are “3. When cquilibrium is interfered with it is re-established by concerned, because the particles of matter (those of a inequalities of exchange. And, in a medium of constant temper gas, for instance) are excessively small in comparison with to the law that difference of temperature diminishes in geometrical the dimensions of any of our forms of apparatus for meaprogression in successive equal intervals of time.

suring temperatures. Something akin to this statement "4. If into a locality at uniform temperature a reflecting or refract- has often been assumed as a direct result of experiment : ing surface is introduced, it has no effect in the way of changing

a number of bodies (of any kinds) within the same imperthe temperature at any point in that locality.

“5. "If into a locality otherwise at uniform temperature there is vous enclosure, which contains no source of heat, will ultiintroduced a warmer or a colder body, and next a reflecting or refract-mately acquire the same temperature. This form is more ing surface, the points on which the rays cmanunting from the body arc general than that above, inasmuch as it involves conthrown by these surfaces will be affected, in the sense of being siderations of dissipation of energy. Either of them, were warmed if the body is warmer, and cooled if it is colder.

“6. A reflecting body, heated or cooled in its interior, will acquire it strictly true, would suffice for our present purpose. the surrounding temperature more slowly than would a non-reflector. But neither statement can be considered as rigorously true.

7. A reflecting body, heated or cooled in its interior, will less We may employ them, however, in our reasoning as true affect (in the way of heating or cooling it) another body placed at a

in the statistical sense; but we must not be surprised if little distance than would a non-reflecting body under the same circumstances.

we should find that the assumption of their rigorous truth "All these consequences have been verified by experiment, except may in some special cases lead us to theoretical results that which regards the refraction of cold. This experiment remains which are inconsistent with experimental facts,—_.e., if to be made, and I confidently predict the result, at least if the we should find that deviations from an average, which are refraction of cold can be accurately observed. This result is indicated in the fourth and fifth consequences [above), and they might

on far too minute a scale to be directly detected by any of thus be subjected to a new test. İt is scarcely necessary to point

our most delicate instruments, may be seized upon and ont here the precautions requisite to guard against illusory results converted into observable phenomena by some of the of all kinds in this matter.'

almost incomparably more delicate systems which we call 10. There the matter rested, so far as theory is con individual particles of matter. cerned, for more than half a century. Leslie and, after 13. The next great advance was made by Balfour him, many others added fact by fact, up to the time of De Stewart. The grand novelty which he introduced, and la Provostaye and Desains, whose experiments pointed to from which all his varied results follow almost intuitively, a real improvement of the theory in the form of specializa- is the idea of the absolute uniformity (qualitative as well as tion. But, though such experiments indicated, on the quantitative) of the radiation at all points, and in all direcwhole, a proportionality between the radiating and absorb- tions, within an enclosure impervious to heat, when thermal ing powers of bodies and a diminution of both in the case equilibrium has once been arrived at. (So strongly does of highly reflecting surfaces, the anomalies frequently met he insist on this point that he even states that, whatever with (depending on the then unrecognized colour-differences be the nature of the bodies in the enclosure, the radiation of various radiations) prevented any grand generalization. there will, when equilibrium is established, be that of a The first real step of the general theory, in advance of black body at the same temperature. He does not expressly what Prévost had achieved, and it was one of immense say that the proposition will still be true even if the bodies import, was made by Balfour Stewart in 1858. Before we can radiate, and therefore absorb, one definite wave-length take it up, however, we may briefly consider Prévost's state-only; but this is a legitimate deduction from his statements, putting aside his erroneous views as to the nature 1 Trans, R. S. E., 1858 ; see also Phil. Jag., 1863, i. p. 354.

ments. To this we will recur.) His desire to difficulties of surface-reflexion led him to consider the pediae dark ground when it is taken out of the fire and examined

Hence he concluded that his extension tion inside an imperfectly transparent body in the enclo- of Prévost's theory was true for luminous rays also. sure above spoken of. He thus arrived at an immediate 16. In this part of the subject he had been anticipated, proof of the existence of internal radiation, which recruits for Fraunhofer had long ago shown that the flame of a the stream of radiant heat in any direction step by step candle when examined by a prism gives bright lines (i.c., precisely to the amount by which it has been weakened by maxima of intensity of radiation) in the position of the absorption. Thus the radiation and absorption rigorously constituents of a remarkable double dark line (i.e., minima compensate one another, not merely in quantity but in of radiation) in the solar spectrum, which he called D. quality also, so that a body which is specially absorptive Hallows Miller had afterwards more rigorously verified the of one particular ray is in the same proportion specially exact coincidence of these bright and dark lines. But radiative of the same ray, its temperature being the same Foucault i went very much farther, and proved that the in both cases. To complete the statement, all that is electric arc, which shows these lines bright in its spectrum, necessary is to show how one ray may differ from another, not only intensifies their blackness in the spectrum of sunviz., in intensity, wave-length, and polarization.

light transmitted through it, but produces them as dark 14. The illustrations which Stewart brought forward in lines in the otherwise continuous spectrum of the light support of his theory are of the two following kinds. (1) He from one of the carbon points, when that light is made by experimentally verified the existence of internal radiation, reflexion to pass through the arc. Stokes about 1850 to which his theory had led him. This he did by show- pointed out the true nature of the connexion of these ing that a thick plate of rock-salt (chosen on account of its phenomena, and illustrated it by a dynamical analoyy comparative transparency to heat-radiations) radiates more drawn from sound. He stated his conclusions to Sir W. than a thin one at the same temperature, surrounding Thomson, who (from 1852 at least) gave them regularly bodies being in this case of course at a lower temperature, in his public lectures, always pointing out that one conso that the effect should not be masked by transmission. stituent of the solar atmosphere is certainly sodium, and The same was found true of mica and of glass. (2) He that others are to be discovered by the coincidences of showed that each of these bodies is more opaque to radia- solar dark lines with bright lines given by terrestrial subtions from a portion of its own substance than to radiation stances rendered incandescent in the state of vapour. in general. Then comes his conclusion, based, it will be Stokes's analogy is based on the fact of synchronism (long observed, on his fundamental assumption as to the nature of ayo discussed by Hooke and others), viz., that a musical the equilibrium radiation in an enclosure. It is merely a string is set in vibration when the note to which it is tuned detailed explanation that, onco equilibrium has been arrived is sounded in its neighbourhood. Hence we have only to at, the consequent uniformity of radiation throughout the imagine a space containing a great number of such strings, interior of a body requires the step-by-step compensation all tuned to the same note. Such an arrangement would already mentioned. And thus he finally arrives at the state form, as it were, a medium which, when agitated, would ment that at any temperature a body's radiation is exactly give that note, but which would be set in vibration by, the same both as to quality and quantity as that of its and therefore diminish the intensity of, that particular absorption from the radiation of a black body at the same note in any mixed sound which passed through it. temperature. In symbolical language Stewart's proposi 17. Late in 1859 appeared Kirchhofl's first paper on tion (extended in virtue of a principle always assumeil) the subject. He supplied one important omission in amounts to this at any one temperature let R be thé Stewart's development of the theory by showing why it mdiation of a black body, and eR (where e is never greater is necessary to use as an absorbing body one colder than than 1) that of any other substànce, both for the same the source in order to produce reversal of spectral lines. definite wave-length; then the substance will, while at This we will presently consider. Kirchhoff's proof of the that temperature, absorb the fraction e of radiation of that quality of radiating and absorbing powers is an elaborate ware-length, whatever be the source from which it comes. but unnecessary piece of mathematics, called for in conThe last clause contains the plausible assumption already sequence of his mode of attacking the question. He chose referred to. Stewart proceeds to show, in a very original to limit his reasoning to special wave-lengths by introducand ingenious way, that his result is compatible with the ing the complex mechanism of the colours of ihin plates known facts of reflexion, refraction, &c., and arrives at (LIGHT, vol. xiv. }": G0S), and a consequent appeal to the conclusion that for internal radiation parallel to a Fourier's theorem (HARMONIC ANALYSIS, Vol. xi. )". 481), plane the amount is (in isotropic bodies) proportional to instead of to the obviously permissible assumption of a subthe refractive index. Of course, when the restriction of stance imperfectly transparent for one special wavelength, fullelism to a plane is removed the internal radiation is but perfectly transparent for all others; and he did not, found to be proportional to the square of the refractive as Stewart had clone, carry his reasoning into the interior indler. This obvious completion of the statement was first of the bouly. With all its elaboration, liis mode of attarkFiren hy Stewart himself at a somewhat later date. ing the question leads 17s no farther than could Stewart's.

1.3. So far Stewart had restricted his work to "ark Both are ultimately based on the final equilibrium of temhear," as it was then called ; and he says that he did so perature in an enclosure required by Carnot's principles etpressly in order to contine himself to rays " which were anal both arı, as a consequener, oqually inapplicable to universally acknowledged to produce heat by their absorp- exceptional cases, such as the behaviour of tuotesent or tion." But he soon proceeded to apply himself to luminous phosphorescent substances. In fartiste THERMODYNAMI) radiations. And here he brought forward the extremely (arnotis principle is established only on a statistical ba-is important fact that "colourel glasses invariably lose their of averages, and is not necessarily true when we are dealcolour in the fire " when exactly at the temperature of the ing withi portions of space, which, though of essentially puls lwhind them, i.e., they compensate exactly for their tinite dimensions, are extremely small in comparison with almorption by their radiation. But a red glass when the sentient part of even the tiniest in-trument des lieu-115colder than the coals behind appears red, while if it lie in temperature. lintter than they are it appears green. He also showed

ILT:!... 7:! Felmars 1910 "11":11:2., , that a piece of china or earthenware with a dark pattern ::-.1, Jos... I'mo!

....Si. on a light ground appears to have a light pattern on a P... ... [": 1

.1.09 ..2:03

18. Kirchhoff's addition to Stewart's result may be given | nature of the surface of the cooling body. It is found as follows.

Let radiation r, of the same particular wave to be proportional to a power of the pressure of the length as that spoken of in $ 14, fall on the substance; er surrounding gas (the power depending on the nature of of it will be absorbed, and (1 – e)transmitted. This will the gas), and also to a definite power of the temperature be recruited by the radiation of the substance itself, so excess. The reader must be referred to French treatises, that the whole amount for that particular wave-length especially that of Desains, for further information. becomes (1 – e)r +eR, or r e(r R). Thus the radiation 23. Our knowledge of the numerical rate of surfaceis weakened only when R<r, a condition which requires emission is as yet scanty, but the following data, due to that the source (even if it be a black body) should be at Nicol, may be useful in approximate calculations. Loss a higher temperature than the absorbing substance ($ 4, in heat units (1 lb water raised 1° C. in temperature) per above). But the converse is, of course, not necessarily square foot per minute, from true. This part of the subject, as well as the special work

Bright copper

0:51 0.42 of Kirchhoff and of Bunsen, belongs properly to spectrum

Blackened copper.

1:46 1:35. analysis (sce SPECTROSCOPY).

The temperatures of body and enclosure were 58° C. and 8° 19. From the extension of Prévost's theory, obtained in C., and the pressure of contained air in the three columns either of the ways just explained, we see at once how the was about 30, 4, and 0.4 inches of mercury respectively. constancy of the radiation in an enclosure is maintained. The enclosure was blackened. In the neighbourhood of and perpendicular to the surfaces 24. Scanty as is our knowledge of radiation, it is not at of a black body it is wholly due to radiation, near a all surprising that that of convection should be almost nil, transparent body wholly to transmission. A body which except as regards some of its practical applications. Here reflects must to the same extent be deficient in its radia we have to deal with a problem of hydrokinetics of a tion and transmission; thus a perfect reflector can neither character, even in common cases, of far higher difficulty radiate nor transmit. And a body which polarizes by than many hydrokinetic problems of which not even apreflexion must supply by radiation what is requisite to proximate solutions have been obtained. render the whole radiation unpolarized. A body, such as 25. What is called Doppler's Principle (LIGHT, vol. xiv. a plate of tourmaline, which polarizes transmitted light, p. 614) has more recently2 led Stewart to some curious must radiate light polarized in the same plane as that speculations, which a simple example will easily explain. which it absorbs. Kirchhoff and Stewart independently Suppose two parallel plates of the same substance, pergave this beautiful application.

fectly transparent except to one definite wave-length, to 20. Empirical formulæ representing more or less closely be moving towards or from one another. Each, we prethe law of cooling of bodies, whether by radiation alone or sume, will radiate as before, and on that account cool ; by simultaneous radiation and convection, have at least an but the radiation which reaches either is no longer of the historic interest. What is called Newton's Law of Cool- kind which alone it can absorb, whether it come directly ing was employed by Fourier in his Théorie Analytique from the other, or is part of its own or of the other's de la Chaleur. Here the rate of surface-loss was taken as radiation reflected from the enclosure. Hence it would proportional to the excess of temperature over surrounding appear that relative motion is incompatible with temperbodies. For small differences of temperature it is accurate ature equilibrium in an enclosure, and thus that there enough in its applications, such as to the corrections for must be some effect analogous to resistance to the motion. loss of heat in experimental determinations of specific heat, We may get over this difficulty if we adopt the former &c., but it was soon found to give results much below the speculation of Stewart, referred to in brackets in § 13 truth, even when the excess of temperature was only 10° C. above. For this would lead to the result that, as soon as

21. Dulong and Petit, by carefully noting the rate of either of the bodies has cooled, ever so slightly, the radiacooling of the bulb of a large thermometer enclosed in a tion in the enclosure should become that belonging to a metallic vessel with blackened walls, from which the air black body of a slightly higher temperature than before, had been as far as possible extracted and which was main- and thus the plates would be furnished with radiation tained at a constant temperature, were led to propound which they could at once absorb, and be gradually heated the exponential formula Aut + B to represent the radia- to their former temperature. tion from a black surface at temperature

As this is an 26. A very recent speculation, founded by Boltzmann 3 exponential formula, we may take t as representing absolute upon some ideas due to Bartoli, is closely connected in temperature, for the only result will be a definite change principle with that just mentioned. This speculation is of value of the constant 1. Hence if to be the temper- highly interesting, because it leads to an expression for the ature of the enclosure, the rate of loss of heat should be amount of the whole radiation from a black body in terms A (a' - *), or Aao(at-70 – 1). The quantity A was found of its absolute temperature. Boltzmann's investigation by them to depend on the nature of the radiating surface, may be put, as follows, in an exceedingly simple form. It but a was found to have the constant value 1.0077. As was pointed out by Clerk Maxwell, as a result of his the approximate accuracy of this expression was verified electro-magnetic theory of light, that radiation falling on by the experiments of De la Provostaye and Desains for the surface of a body must produce a certain pressure. It temperature differences up to 200° C., it may be well to is easy to see (most simply by the analogy of the virial point out two of its consequences. (1) For a given differ- equation, MECHANICS, vol. xv. p. 719) that the measure of ence of temperatures the radiation is an exponential func- the pressure per square unit on the surface of an impervition of the lower (or of the higher) temperature. (2) For ous enclosure, in which there is thermal equilibrium, must a given temperature of the enclosure the radiation is as be one-third of the whole energy of radiation per cubic (1.0077)0 – 1, or 0(1+0.00380+ ...), where 0 is the unit of the enclosed space. We may now consider a rctemperature excess of the cooling body. Thus the New versible engine conveying heat from one black body to tonian law gives 4 per cent. too little at 10° C. of difference. another at a different temperature, by operations alternately

22. Dulong and Petit have also given an empirical of the isothermal and the adiabatic character (THERMOformula for the rate of loss by simultaneous radiation and DYNAMICS), which consist in altering the volume of the enconvection. This is of a highly artificial character, the part due to radiation being as in the last section, while that

1 Proc. R. S. E., vii. 1870, p. 206.

2 Brit. Assoc. Report, 1871. due to convection is independent of it, and also of the

3 Wiedemann's Ann., 1884, xxii.

dv

closure, with or without one of the bodies present in it. | widen out into considerable plains, abounding with small For one of the fundamental equations gives

rivulets. The hills for the most part present smooth and DE dp

rounded outlines, but the valley of the Wye is famed for =låt -P,

its beauty. The higher ranges are covered with heath, where t is the absolute temperature. If f be the pressure but there is good pasturage on the lower slopes. The on unit surface, 3f is the energy per unit of volume, and smaller elevations are frequently clothed with wood. The this equation becomes

prevailing strata are the Lower Silurian rocks; but in the - =35.

east there is a considerable area occupied by Old Red Sanddt

stone, and throughout the county felspathic ash and greenHence it follows at once that, if the fundamental assump- stone are found, while near Old Radnor there is a large tions be granted, the energy of radiation of a black body patch of Silurian limestone. Lead and copper are said to per unit volume of the enclosure is proportional to the exist, but not in quantities sufficient to pay the working. fourth power of the absolute temperature. It is not a There are saline, sulphurous, and chalybeate wells at Llanlittle remarkable that Stefan ? had some years previously drindod. The Wye enters the county in the north-west, shown that this very expression agrees more closely with 18 miles from its source in Plinlimmon, and flowing in a the experimental determinations of Dulong and Petit than south-easterly direction divides it from Brecknock, until it does their own empirical formula.

bends north-east and reaches Hay, after which it for some 27. It would appear from this expression that, if an distance forms the boundary with Hereford. Its prinimpervious enclosure containing only one black body in cipal tributary is the Ithon, which flows south-west and thermal equilibrium is separated into two parts by an joins it 7 miles above Builth. The Teme, flowing southimpervious partition, any alteration of volume of the part east, forms the northern boundary of the county with not containing the black body will produce a corresponding Shropshire. The Llugw, rising in the northern part of alteration of the radiation in its interior. It will now the county, flows south-east into Hereford, a little below correspond to that of a second black body, whose tempera- Presteigne. ture is to that of the first in the inverse ratio of the fourth Agriculture.— The climate is somewhat (lamp, and in the spring roots of the volumes of the detached part of the enclosure for pasturage, but there is some good arable land in the valleys in

cold and ungenial. The greater part of the county is suitable only 28. Lecher? has endeavoured to show that the distri- the southern and south-eastern districts, which produces excellent bution of energy among the constituents of the radiation crops of turnips, oats, and Welsh barley, the soil being chietly from a black body does not alter with temperature. Such open shaly clay, although in the east there is an admixture of reil a result, thongh apparently inconsistent with many well- ninths of the total area, under cultivation, and of these 114,242

In 1884 there were 156,628 acres, or about fiveknown facts, appears to be consistent with and to harmonize acres, or about four-fifths, were in permanent pasture. Of the many others. It accords perfectly with the notion of the 21,356 acres under corn crops 12,215 acres, or inore than half, absolute uniformity (statistical) of the energy in an en

were under oats, whilst wheat occupied 5200 acres and barley 3853. closure, and its being exactly that of a black body, even if Green cropus cupical only 7100 aeres, of which 1107 were under the contents (as in $ 25) consist of a body which can radiate used solely for agricultural purposes), cattle 30,917 (10,223 cows one particular quality of light alono. And if this be the and

And if this be the and heifers in milk or in call), and sheep as many as 241,771. case it will also follow that the intensity of radiation of The inhabitants are dependent almost solely on agriculture, the any one wave-length by any one body in a given state

manufactures being confined chiefly to coarse cloth, stockings, and

flannel for home use. depends on the temperature in exactly the same way as

kulirus. — The county is intersected by several lines: the does the whole radiation from a black body. l'nfor- ('entral Wales Railway runs south-west from Knighton to Llantunately this last deduction does not accord with Melloni's dorery ; another line runs south-eastwarıls by Rhayader anil Builth results; at least the discrepance from them would appear while another branch line passes by Kinrton to Noir Radnor.

and joins the Herefordd line, which passes by Hay and Talgarth ; to be somewhat beyond what could fairly be set down to

suministration and Population.— Runor comprises six hun. error of experiment. But it is in thorough accordance dreds

, but contains no municipal borough. It has one court of with the common assumption (§ 1-4) that the percentage quarter sessions and is divided into six patty and spurial sessional

divisions. The ancient borough of Radnor population 2005) is alusorption of any particular radiation does not depend on

governeil by the provisions of an old Charter, and has a commission the temperature of the source. The facts of fluorescence of the peace. The county contains sixty civil parishes with part of and phosphorescence, involving the radiation of visible one other, and is partly in the viourse of St Devil's and partly in mys at temperatures where even a black bouly is invisible, that of Hereforil. It returns one inembus to the House of comhave not yet been dealt with under any general theory of 23,928, of vom 11,939 were males and 11,549 females. The radiation ; though Stokes has pointed out a dynamical number of inhabited 2011*** was 1775. The averas nuber of explanation of a thoroughly satisfactory character, they re persons to an as to was 0.09 and of ar to a posson 11-73. main outside the domain of Carnot's principle. (P. C. T.) IL JUIN (nel Iniquities. — Durin: the Roman cu' ljution the RADIOMETER. See PNEUMATICS, Vol. xix. p. 2:19.

clistriit was included in the porosinca of Siluria. The Roman soal

from Chester to Carmarthen into send the mouthern ritromity of RADISH. See HORTICULTURE, vol. xii. PP. 286, 287.

the county ner Veltown anıl, following the riley of the Ithon, RIDSOR, an inland county of South Wales, is situated crossed the Winand control or knokshire in in the town of lwert steen 53 and 5' 23' X. lat, and between 2' 57' Builth. The Trains of a Roman sturion a: I'vun der Llanand 3° 2,5 W. long., and is bounded E. by Hereford and rimbon, anılar !! Ps Hill 1 Presi_i_h" tliesojn a vry good

("\.1mple of a Britislim; Tln litrit il.as attesund indeed Shropshire, S. by Montgomery, W. by Cariligan, and s.

chilli in Posis, but partis in Cilt 11.1 pantly in Firvwn. It Big Brerkn««k. its greatest length from north to south is 1.2-1.ade 1 county ly Henry VIII llun1: WNB Minya about 30 miles, and its greatest breath from east to went ferdel. Tham Rinor is als) of viry grit qutility, and ours

in the Cambril 11 s ainuut 33 miles. The area is 276,552 acres, or 43? .quare Candles Luming a bi, .. t. col. 11 min of

Cry 11!4. Tito Mauint miles.

importante in tu: of the loop ('10- Hlır, fov::16. I got to l'is. The greater part of the surface of the county is hily: tr- in 1113, 11:10 min tosianti Villil...if and the centre is occupied by a mountainous tract called clipele Trolls 72!1. portion t'aid''st! Willmen Radnor Forest, running nearly cast and west, its highest urol 10 11.78 vitin : r . 4.3.1:111: 1...: 141.81","51. siimmit renching 2163 feet. Towards the south and RADOM, a orumut of 111. Pripving a triansouth-ca-t the hills are much less elevated and the vallis ular : jace Hot!$on to lintula and il... Paulluwood i deswmshey, d. k..Il in Wien, 1579.

on the ... Wirs and similar, on the E. lv Lublin, : Indemann's Ann., 1852, xvii.

on the S. lix du-trilli Galioji and Kietro, ariel on the W.

by Piotrków. The area is 4765 square miles. Its southern Radom, which is mentioned in historical documents of the year part stretches over the hilly plateau of Poland, which 1216, at that time occupied the site of what is now Old Radom. consists of short ridges of hills from 800 to 2000 feet in Jadwiga was elected queen of Poland in 1382, and here too in

New Radom was founded in 1340 by Casimir the Great. Here height, intersected by deep valleys, and is known as the 1401 the first act relating to the union of Poland with Lithuania Sandomir Heights. These heights are thickly wooded ; was signed ; the "seim” of 1505, where the organic law of Poland the valleys, running west and east and watered by several was sworn by the king, was also held at Radom. Several great tributaries of the Vistula, are excellently adapted for agri- | fires, and still more the Swedish War, were the ruin of the old city. culture. Farther north in its central portion the contour of later on, in 1809, it became capital of the Radom department of

After the third partition of Poland'it fell under Austrian rule ; the government is level, the soil fertile, and the surface, the grand-duchy of Warsaw. In 1815 it was annexed to Russia which is diversified here and there with wood, is further and became chief town of the province of Sandomir. broken up by occasional spurs, 800 feet in height, of the RAEBURN, SIR HENRY (1756-1823), portrait-painter, Lysa Góra Mountains. The northern districts, where the was born at Stockbridge, à suburb of Edinburgh, on Pilica joins the Vistula, consist of low flat tracts with the 4th of March 1756, the son of a manufacturer of undefined valleys, exposed to frequent floods and covered the city. He was early left an orphan. Being placed in over large areas with marshes; the basin of the Pilica, Heriot's Hospital, he received there the elements of a sound notorious for its unhealthiness, is throughout a low marshy education, and at the age of fifteen was apprenticed to a plain. Devonian, Carboniferous, Permian, and Triassic goldsmith in Edinburgh. Here he had some little oppordeposits appear in the southern plateau, Chalk and tunity for the practice of the humbler kinds of art, and Jurassic in the middle, and Tertiary in the north. Wide various pieces of jewellery, mourning rings and the like, tracts are covered with Glacial deposits,—the Scandinavian adorned with minute drawings on ivory by his hand, are erratics reaching as far south as Ilža; these last in their still extant. Soon he took to the production of careturn are covered with widely spreading post-Glacial lacus- fully finished miniatures; and, meeting with success and trine deposits. The Vistula skirts the government on patronage, he extended his practice to oil-painting, being the south and east and is an important means of com- all the while quite self-taught. The worthy goldsmith his munication, several hundreds of light boats (galary) master watched the progress of his pupil with interest, descending the river every year, while steamers ply as far gave him every encouragement, and introduced him to up as Sedomierz. The Sędomierz district is occasionally David Martin, who had been the favourite assistant of exposed to disastrous inundations of the river. The tribu- Allan Ramsay junior, and was now the leading portraittaries of the Vistula (Radomka, Kamienna, and several painter in Edinburgh. Raeburn received considerable others) are but short and small, while those of the Pilica assistance from Martin, and was especially aided by the are mere streams sluggishly flowing amidst marshes. loan of portraits to copy. Soon the young painter had

The population (614,830 in 1882) is Polish for the most part, one- gained sufficient skill to render it advisable that he seventh being Jews. According to creed the proportions are

should devote himself exclusively to art. When in his Roman Catholic 84:0 per cent., Jewish 14:6, Protestant 1.3, and Greek 0.1 per cent. The chief occupation of the inhabitants is twenty-second year he was asked to paint the portrait agriculture, the principal crops being wheat, oats, rye, potatoes, of a young lady whom he had previously observed and and beetroot (for sugar). Corn is exported and potatoes largely admired when he was sketching from nature in the fields. used for distillation. In 1879 there were 148 manufacturing establishments (197 in 1883), employing 1708 hanıls, with an aggregate widow of Count Leslie. The lady was speedily fascinated

She was the daughter of Peter Edgar of Bridgelands and procluction of 2,121,000 roubles (£212,000), the more important being tanneries, flour-mills, sugar-works, and several machinery by the handsome and intellectual young artist, and in a and iron-works. These last are suffering, however, from want of month she became his wife, bringing him an ample fortune. wood-fuel, and many of them have recently been closedl. Trade is After the approved fashion of artists of the time, it was not very extensive, the only channel of commerce being the l'istula. There is no lack of philanthropic institutions within the govern- resolved that Raeburn should visit Italy, and he accordment (most of them founded carly in this century), but never- ingly started with his wife. In London he was kindly theless the sanitary condition of the people is deplorable

. Plica received by Sir Joshua Reynolds, who gave him excellent polonica, which is endemic in the government of Radom as well advice as to his study in Rome, especially recommending as in that of Kielce, is widely diffused, no fewer than 15,000 per

He also sons suffering from it, and cognate maladies, such as goitre, scabies, to his attention the works of Michelangelo. and tinca cupitis, are also widely prevalent.

offered him more substantial pecuniary aid, which was The educational institutions include two lycées or gymnasia and declined as unneeded; but Rae urn carried with him two progyınnasia (all at Radom), with 813 male and 287 female

to Italy many valuable introductions from the president pupils, a normal school, a theological seminary at Sandomir, and 170 primary schools (112 in villages), with 8165 scholars.

of the Academy. In Rome he made the acquaintance The government is divided into eight districts, the chief towns of Gavin Hamilton, of Batoni, and of Byers. For the of which are-Radom, Ilża (2750), Konsk (6275), Kozienice (5690), advice of the last-named he used to acknowledge himself Opatow (5200), Opoczno (5585), and Sedomierz, or Sandomir (6265, greatly indebted, and particularly for the recommendation custom-house. Ostrowiec (5290), Staszów (6910), Przedborz (6345), that “he should never copy an object from memory, but, and Szidlowiec (5290) have municipal institutions.

from the principal figure to the minutest accessory, have RADOM, capital of the above government, situated on it placed before him.” After two years of study in Italy the Mleczna, a tributary of the Radomka, 65 miles south he returned to Edinburgh in 1787, where he began a most from Warsaw, is one of the best-built provincial towns of successful career as a portrait-painter. In that year he Poland. Lublin Street has a number of fine shops, and executed an admirable seated portrait of the second Lord there are two well-kept public gardens. The permanent President Dundas. population in 1882 was 12,970, half of whom were Jews, Of his carlier portraiture we have interesting examples and the town is rapidly growing towards the south-east in the bust-likeness of Mrs Johnstone of Baldovie and in Though an old town, Radom has no interesting antiquities. the three-quarter-length of Dr James Hutton, works which, The church of St Wlaclaw, contemporary with the founda- if they are somewhat timid and tentative in handling and tion of the town, was transformed by the Austrians into a wanting in the trenchant brush-work and assured mastery storehouse, and subsequently by the Russian Government of subsequent productions, are full of delicacy and charinto a military prison. The old castle is in ruins, and the acter. The portraits of John Clerk, Lord Eldin, and of old Bernardine monastery is now used as barracks. The Principal Hill of St Andrews belong to a somewhat later manufactures are unimportant, but trade has been lately period. Raeburn was fortunate in the time in which he increasing

practised portraiture. Sir Walter Scott, Blair, Mackenzie,

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