HEATH 



experimental basis of the modern 

 branch of physics known as 

 thermo-dynamics. Its main de- 

 velopment on the theoretical 

 side is contained in the researches 

 of four great physicists : Carnot of 

 France, Clausius and Helmholtz 

 of Germany, and Lord Kelvin. 

 Its great feature is the width of 

 view and the fundamental nature 

 of its conclusions, which can be 

 arrived at without any appeal to 

 a theory of heat at all. 



Nevertheless, as the human 

 mind must speculate on ultimate 

 nature, there is no doubt that its 

 conclusions are much easier to 

 relate to the dynamical theory of 

 heat than to the material. In 

 thermal phenomena we believe 

 we are witnessing the variations 

 which go on in the degree and in- 

 tensity of the motions of the mole- 

 cules of a body. Increased agita- 

 tion . produces the sensations of 

 heat, involves a sundering apart 

 which we see in expansion, may 

 even result in a complete rupture 

 between molecules against co- 

 hesion, as when fusion or vaporisa- 

 tion takes place. What is trans- 

 ferred from body to body is not a 

 material, but an amount of energy 

 of motion, and so the science of 

 heat in its widest development be- 

 comes merged in the study of 

 transformations of Energy. 



Bibliography. Theory of Heat, J. 

 Clerk-Maxwell, 2nd ed. 1872; 

 Sketch of Thermodynamics, P. G. 

 Tait, 2nd ed. 1877 ; Heat as a Mode 

 of Motion, J. Tyndale, 7th ed. 1887 ; 

 Theory of Heat, T. Preston, 1 894 ; 

 Outline of the Theory of Thermo- 

 dynamics, E. Buckingham, 1900 ; 

 Treatise on Thermodynamics, M. 

 Planck, Eng. trans. A. Ogg, 1903 ; 

 Text Book "of Physics, Heat, J. H. 

 Poyntings and J. J. Thomson, 4th 

 ed. 1911; Methods of Measuring 

 Temperature, E. Griffiths, 1918. 



Heath (Erica). Popular name 

 for a genus of wiry evergreen 

 shrubs of the natural order Erica- 

 ceae (q.v.). They are natives of 

 Europe, Africa, and N. Asia. The 

 slender, rigid leaves are much like 

 small pine-needles, and are dis- 

 posed mostly in whorls. The four 

 petals are always united to form an 

 egg-shaped, bell-shaped, or tubular 

 corolla. 



Four species are natives of Brit- 

 ain, including purple heath (E. 

 cinerea), that colours the heaths 

 and moorlands in summer ; the 

 cross-leaved heath (E. tetralix), 

 with delicately rosy-tinted flowers, 

 in moist hollows ; the crimson- 

 flowered fringed heath (E. ciliaris) 

 of S. W. England ; and the Cornish 

 heath (E. vagans) of the Lizard and 

 Land's End. A fiftn species, the 

 Irish heath (E. mediterranea), 

 eecurs in W. Ireland. Many of the 



3902 



exotic forms, particularly those 

 of S. Africa, are grown in English 

 greenhouses ; but the first species 

 to be introduced was the S. Euro- 

 pean briar-root (E. arborea) in 1856. 



Some of the most popular forms 

 are hybrids of garden origin. In 

 the open air they flourish in sand 

 or peat in any position where rhodo- 

 dendronswould thrive. They should 

 be planted in autumn or early spring. 

 Greenhouse species are usually 

 grown as specimens in pots, in soil 

 composed of two-thirds peat and 

 one third silver sand. They are 

 chiefly used for decorative purposes 

 in early spring, and, after flowering, 

 are stood out in the open air in a 

 warm and sunny position before 

 being taken into the greenhouse 

 again in autumn. They are propa- 

 gated by cuttings in spring and 

 division of the plants in autumn, or 

 may be increased by layering (q.v. ). 



Heath. Literally, a place grown 

 over with shrubs, and derived from 

 the plant of this name. Heaths are 

 found in various parts of Great 

 Britain, notably in Surrey, e.y. 

 Walton Heath and Burgh Heath. 



Heath, NICHOLAS (c. 1501-78). 

 English prelate. Born in London, 

 he was educated at both Oxford 

 and Cambridge. He was ordained 

 and, adhering to the older faith, 

 was made bishop of Rochester in 

 1539 ; in 1543 he was translated to 

 Worcester. Heath's opposition to 

 the reformed teaching led to the 

 loss of his bishopric in 1551, but 

 soon after Mary came to the throne 

 he was made archbishop of York 

 and lord chancellor. Finding 

 Elizabeth determined on a mod- 

 erate course, he refused to crown 

 her. He was, therefore, deprived 

 of his archbishopric and lived in 

 retirement for the rest of his days. 



Heathcoat, JOHN (1783-1861). 

 British inventor. Born at Duffield, 

 Derbyshire, Aug. 7, 1783, he was 

 apprenticed to a smith, afterwards 

 taking over a machinery business 

 in Nottingham. He started in 

 business as a lace and net manu- 

 facturer in Loughborough, and in 

 1808 produced his great invention, 

 a machine for making imitation 

 pillow lace. Other inventions in- 

 cluded a steam plough and a pro- 

 cess for purifying salt. In 1816 

 Heathcoat's factory at Lough- 

 borough was destroyed by the Lud- 

 dites (q.v.) ; consequently he moved 

 to Tiverton, where he set up as a 

 lace manufacturer. From 1832-59 

 he was M.P. for Tiverton, and there 

 he died, Jan. 18, 1861. The busi- 

 ness at Tiverton still flourishes. 



Heather (Calluna vulgaris). 

 Gregarious shrub of the natural 

 order Ericaceae. It is a native of 

 Europe, W. Siberia, Azores, and N. 

 America. The leaves are three- 



HEATING 



sided and minute, overlapping in 

 four rows ; the flowers honeyed and 

 rosy-purple, the four stiff sepals 

 being much larger than the bell- 

 shaped corolla. The plant covers 

 vast extents of heath and moor- 

 land. The wiry stems and branches 

 are useful for thatching, making 

 brooms, and for fuel. See Ericaceae. 

 Heathfield. Village of Sussex, 

 England. It is 15 m. from Tun- 

 bridge Wells with a station on the 

 L.B. & S.C. Rly. It stands on 

 the Cuckmere, and had once a 

 foundry where cannon were made 

 The church of All Saints is mainly 

 a 15th century building which has 

 been restored. Lord Heathfield, the 

 defender of Gibraltar, took his 

 title from here ; he lived at Heath- 

 field House, the old seat of the 

 Dacres, and is buried in the church. 

 From Gibraltar Tower, erected to 

 his memory, there is a fine view. 



Heathfield, GEORGE AUGUSTUS 

 ELIOTT, IST BARON (1717-90). Bri- 

 tish soldier. Born at Stobs, Rox- 

 burg h shire, 

 Dec. 25, 1717, 

 he was edu- 

 cated at Lei- 

 den university 

 and served 

 with the 

 Prussian army, 

 1735-36. On 

 his return to 

 England he 

 trained at 

 Woolwich and 



1st Baron Heathfield, 

 British soldier 



After Reynold! 



was commissioned as field engineer. 

 In 1739 he joined the 2nd Life 

 Guards, served with his regiment in 

 the war of the Austrian succession 

 and was wounded at Dettingen 

 and Fontenoy. 



Colonel of the 1st Light Horse in 

 1759, he distinguished himself in 

 the Seven Years' War under Prince 

 Ferdinand in the campaign of 

 1759-61. Promoted major-general 

 in 1759, he was second in command 

 in the Cuba expedition of 1763, 

 and became lieutenant-general in 

 1765. In 1774 he was appointed 

 commander-in-chief in Ireland, but 

 the following year was sent to 

 command Gibraltar. In 1779 the 

 Spanish opened the siege of the 

 fortress, which Heathfield held 

 stubbornly for four years, when he 

 was relieved by Lord Howe. On 

 his return to England he was 

 knighted and in 1787 raised to the 

 peerage as Lord Heathfield, baron 

 of Gibraltar. He died at Aix-la- 

 Chapelle, July 6, 1790. 



Heating. In climates subject to 

 low temperatures, it is necessary 

 for health and comfort to produce 

 artificial warmth. Remains of 

 Roman villas in Britain reveal the 

 method of warming by hypocausts 

 flues running under the floor and 



