508 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



fallen in a feeble drizzle, now descended at once in a copious shower, as 

 though it had been awaiting' the signal of the electrical flash to do its 

 errand of mercy. 



A word here about the form of these mountains, before proceeding, with 

 further descriptions. Like all mountains composed of stratified rocks, 

 those of North Carolina run in lengthened ranges, mainly from north-east 

 to south-west. In countries where the unstratified rocks prevail, the 

 mountains are often thrown up into dome-shaped forms. Here and there, 

 however, in North Carolina, there are points which rise dome-like, a thousand 

 feet above the ordinary elevation of tlie surrounding portions of the moun- 

 tains; but they differ in nothing except altitude, from the geology of the 

 country at large. These domes in the section of the country under con- 

 sideration, attain a height of three thousand feet above the beds of the 

 rivers, and about five thousand four hundred feot above the sea level. 

 Some of them reach an elevation of two hundred or three hundred feet 

 above the line at which the ordinary forest trees can grow, and are desti- 

 tute of timber, though covered with grasses and flowers. Here and there 

 a group of briers, laurels, azalias, and other shrubs add their presence to 

 vary the scenery of these celestial prairies. 



These elevated domes have much to do with the formation of clouds and 

 the production of rain. They are locally called balls, from their round 

 appearance and naked surface. In the clearest days often, the clouds can 

 be seen forming around them at a greater or less distance above or below 

 their summits. At times the rain-fall is limited to the area around the 

 ball, where the cloud spends itself, so that its remaining vapor is drifted 

 off or dissolved again in the atmosphere. At other times the clouds accu- 

 mulate largely, and either from the influence of currents of wind, or from 

 electrical action, they move off so as to water the surrounding mountains 

 and intervening valleys. It is not unusual for two balls, or for the sum- 

 mits of the lower mountains, to be forming wreaths of clouds around their 

 brows at the same moment. These clouds, not unfrequently, are attracted 

 towards each other, and thus the vegetation of the intervening districts has 

 an additional chance of receiving new life and vigor from the rains yielded 

 by this means. 



It is these occasional showers^ which serve to keep up the mountain 

 springs and streams in perpetual flow, and which supply to the animal 

 kingdom the water it demands, in a purity almost equal to the dews of 

 heaven. The general rains of this region, as distinguished from those of 

 local origin, come usually from the west and south-west in broad sheets of 

 clouds overspreading the whole sky. 



On the Itth^July, 1857, I set out from the head of Valley river, a branch 

 of the Hiwassee river, to measure the height of the ball upon Valley river 

 mountain. Making the measurement with " Locke's level," I could at least 

 gain a close approximation to the true height. The distance from the "river's 

 bed to the top of the ball was about five miles, and the elevation two thou- 

 sand nine hundred and eighty-seven feet ; or about three thousand feet 

 above the bed of tlie Hiwassee at Murphy, Nortii Carolina. 



Before reaching the top of the main ball, a cloud came sweeping along, 

 from the direction of the Tusquitta mountain, to the southwest, and poured 



