A V A 



94 



A V A 



ATI 



cated by the percussion of clastic and non-elastic bo- 

 dies, I the resistance of fluids, and for 

 confirming the properties of rotatory motion. His 

 ;il works are his Description of Experiments i 

 his /J 'i Course of Lecturer) his Tveatm 

 .id Rotatory Motions his Trettiitvn 

 t, ISO] ; arid his Disquisition on the Stability 

 of Ships, in the Phil. Trans, for 1798. 



Mr At wood was honoured frith the Copley medal 

 for hii valuable papers in the Transactions of the 

 Society- He died in London on the 1 Itii 

 , BO^i in the 62d year of his age, and was inter- 

 red in St Margaret's church, Westminster. (/') 



AVA, Kingdom of. See Birman Empire. 



AVA, or Aungwa, the name of the ancient ca- 

 pital of the Birman empire, which has been gradually 

 falling into decay since the new capital Ummerapoora 

 was founded. Ava is situated on the banks of the 

 river Irrawaddy, and was divided into ail upper and 

 a lower city. The former was about four miles in cir- 

 cuit, and was protected with a deep ditch and a wall 

 30 feet high. The latter was only about a mile in 

 circumference, but was much stronger than the lower 

 city. Dilapidated temples, roofless houses, and streets 

 covered with rank grass and bushes, form a striking 

 contrast with the rising city of Ummerapoora. See 

 Syme's Embassy to Ava, vol. ii. p. 270. ; and Ren- 

 iiL-i's Memoir, p. 297. See also Birman Empire, 

 and Ummerapoora. (u>) 



AVAL, or Aual, one of the Bahrin islands on 

 the western side of the Persian Gulf. It is about 30 

 miles long and 12 broad, and contains, besides the 

 fortified town of Bahrin, about 60 poor villages. 

 Dates are produced in the island in great abundance; 

 and the best pearls are obtained from its pearl fishery. 

 The duty upon these articles amounts to a lack of 

 rupees. The inhabitants of Aval are Arabs of the 

 Chia persuasion. E. Long. 48 56', N. Lat. 26 45'. 

 See Bahhin. (;') 



AVALANCHES, the name given to those im- 

 mense masses of snow which arc precipitated from 

 the Alps, and which often overwhelm whole villages 

 in their destructive course. When the snow begins 

 to melt by the heat of summer, the water which 

 is produced runs below, and destroys the adhesion 

 between the snow and the earth, and a new snow 

 sometimes falling upon the older mass, increases its 

 weight and determines its fall. These masses are often 

 detached by the impulse of the wind; and the inha- 

 bitants of the Alp s are so convinced that the least 

 sound will produce their fall, that they take off the 

 bells from their mules ; and when the avalanches are 

 too slow in falling at places where they are precipi- 

 tated annually, the inhabitants endeavour to accele- 

 rate their fall by the report of their muskets. These 

 avalanches sometimes occasion dreadful hurricanes. 

 In the winter of 1769, 1770, an avalanche produced 

 by the immense quantity of snow which had fallen, 

 lolled down upon the pastures on the mountain of 

 Sixt in the Alps. The impulse which was given to 

 the air by the fall of this huge mass was so dreadful, 

 that it levelled with the ground a forest of beeches 

 and firs, which covered the declivity of the mountain, 

 topped the cours? of the river Gipre which runs 



through the subjacent valley, and overthrew a num- 

 ber of trees and bams on the opposite shore of the 

 stream. 



" The enow which falls above the superior li- 

 mit of congelation," says Mr Leslie, " from it:; 

 powdery and incohesive quality, is incapable of 

 much accumulation : loosened by the impression of 

 the sun, it slides down, and, gathering force in its 

 descent, it often precipitates itself in those d; 

 o'.is avalanches. But I consider glaciers themselves 

 as formed only by avalanches of a rarer and more 

 formidable kind. The icy zone will accumulate 

 till its weight at last overcomes its cohesion ; then 

 giving way, it will rush down the side of the 

 mountain with irresistible sweep, and spread its shi- 

 vered fragments. This statement agrees with the 

 phenomena, and explains the reason Why glaciers are 

 not observed among the Andes." Experimental In- 

 qriiry, &0. note xxv. p. 537, 510. Sec Gi AcirK. (o) 



AVARS, Avarrs, or Avaiu, a name denoting 

 " far distant," was formerly applied to the inhabi- 

 tants of the more remote districts of Asiatic Sarma- 

 tia, towards the east ; but is now chiefly confined to 

 a horde of barbarians belonging to the nation of the 

 Ogors Or Varchonites, who, about the middle of the 

 6ixth century, when resisting an invasion of the Turks, 

 were defeated with the loss of their king, and 300,000 

 of his subjects. A few, preferring exile to servitude, 

 wandered towards the south in quest of new settle- 

 ments. Their very name inspired terror into the na- 

 tions through which they passed, and tracing the 

 course of the Volga, they stopped not till they had 

 pitched their tents at the foot of mount Caucasus. 

 Here they first heard of the rich kingdoms of the 

 West, and dispatching ambassadors to Constantinople, 

 they proffered their services in defence of the empire, 

 and relying on the terror of their name, demanded as 

 their reward, " precious gifts, annual subsidies, and 

 fruitful possessions." " The whole city," says Gib- 

 bon, " was poured forth to behold with curiosity 

 and terror, the aspect of a strange people ; their long 

 hair, which hung in tresses down their backs, was 

 gracefully bound with ribbons, but the rest of their 

 habit appeared to imitate the fashion of the Huns." 

 The emperor Justinian, worn out with age, and the 

 exertions of an arduous reign, preferred inglorious 

 peace to a doubtful war. He received the Avars as 

 friends and subsidiaries ; and directed their arms 

 against the enemies of Rome. With savage fury, 

 they over ran Germany and Poland. The banks of 

 the Danube, and of the Elbe, were alternately cover- 

 ed with their tents, and many of the conquered tribes 

 were confounded under the name and standard of the 

 Avars. Their power was now established in Eu- 

 rope, and, from being the friends and allies of the 

 Romans, they became their most determined foes. 

 The emperor had transferred his friendship to the 

 Turks, who, pursuing the footsteps of the vanquish- 

 ed Ogors, had appeared in the empire, and branded 

 the Avars witli the title of fugitives and rebels. 

 Their embassy was now received with coldness by 

 Justinian II. ; their threats were disregarded, and 

 their ambassadors dismissed with haughty defiance. 

 Dreading, probably, to meet the Romans in alliance 



Avai 



