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Show TRANSPORTING POWER 174 and great alluvial plains, are prevented from b~ing constantly under water*· Many remarkable illustrations of the power of running water in moving stones and heavy materials were afl'orded by the late storm and flood which occurred on the Srd and 4th of August 18!il9, in Abcrdeenshire and other counties, in Scotland. The floods extended almost simultaneously and in equal violence over a space of about five thousand square miles, being that part of the north-east of Scotland which would be cut off' by two lines drawn from the head of Lochrannoch, one towards Inverness, and another to Stonehaven. All the rivers within that space were flooded, and the destruction of roads, lands, buildings, and crops along the courses of the streams was very great. The elements during this storm assumed all the characters which mark the tropical hurricanes: the wind blowing in sudden gusts and whirlwinds, the lightning and thunder being such as is rarely witnessed in that climate, and heavy rain falling without intermission. The bridge over the Dee at Ballatu consisted of five arches, having upon the whole a water-way of two hundred and sixty feet. The bed of the river on which the piers rested, was composed of rolled pieces of granite and gneiss. The bridge was built of granite, and had stood uninjured for twenty years, but the different parts were swept away in succession by the flood, and the whole mass of masonry disappeared in the bed of the river t. '' The river Dont observes Mr. Farquharson, in his account of the inundations, " has upon my own premises forced a mass of four or five hundred tons of stones, many of them two or three hundred pounds weight, up an inclined plane, rising six feet in eight or ten yards ; and left them in a rectangular heap, about three feet deep on a flat ground; and, singularly enough, the heap ends abruptly at its lower extremity. 4- large stone, of three or four tons which I have known for many years in a deep pool of the river, bas been moved about one hundred yards from its placet." The power even of a small rlvulet, when swoln by rain, in re· moving heavy bodies, was lately exemplified in the College, a • See Article Rivers, Ency. Brit. 1' From the account given by the Rev. James Farquharson, in the Quarterly , J oum. of Sci., &c., No, 12, new series, p. 328. t Ibid., P· 331. OF RUNNING WATER small stream 'W hi' c1 fl · 175 1 ows at eastern. water-shed of the Ch:vimode~ate declivity from the tohn sT w' eJght of gravel an d sand ot-HilJs. Several th ousan d t e Ill, and a bridge then in were transpor~e~ to the plain of away, some of the arch-ston p;ogr:ss of bmldmg was carried thre~-quarters of a ton eaches o whiCh, weighing from half t the rivulet. On the sam ' ":ere propelled two miles d o the abutment of a miJI-de occasiOn, the current tore aw £.own P } . . am a large bl k f ay Jrom Jyr.y, weJghmg nearl two t . - oc o greenstone- or the dis.t ance of a qua r tyc r. of a omn~i,l andI transported th e sampe to occurrmg repeatedly, in whi I e. nstances are related a of gravel are in like manne c 1 from one to three thousand to s day* • r removed to oO 'reat dI'S t ances m. onnes In the cases above d torrent were dammed a bve~e~ to, the waters of the river d partial barriers and 'II ac y the bridges which t dan h ' 1 ustrate th · · . ac e as w en obstructed B . d e Irresistible force of the tendency of. . fl ges are also liable to be d ta current rivers to sh · ft 1 . es royed b or Wtheh rock on which th e 1~ ouIn d ath ~oenu· ct oudrs e, . whereby th e p1. ery, I . en we consider how in . . fi s an s, Is undermined. ve octty of the rivers and sig~I cant are the volume to those of the AI dstreams m our island when and th . ps an othe 1 fi . ' compared e various changes whi h th Ir o ty chams, and how d . uader c e evels of d'.tr ' urmg gone, the various c f . Iuerent distt·icts h =~: ;~.:~h~apse o~ ag:~ ~:g:~;~:p~~c~~: rise t~1floo~:: quantity of 1 .' ay east y con :~:r 0~urope must. be very ~:::i~~~.~mal 'l~hatter distributed a a great portiOn of these t e. at the position thppea~ n;tost irregular, and sl rladvelled materials should now s e existm g water-drainage ·o fl OthU often b ear no relation to ti~~e~~·: as .we shall afterward: ::nt?;;• a nec~ssary conIn 1 unm~g water and subterran: o e combmed opera-rn . mountamous regi' ons an d h. h an movements . w~~~~g of heavy stones by wat .'g northern latitudes the roc~ a adheres to them, and w~;c~s lre~tly assisted by the ice Th mass of less specific rd . orr:~ung together with the e glaciers also of alpi ~ vity t, Is readily borne al ne regiOns, formed of consolidated ong. •s~ mow, a paper by Mr. Cu. lle. y, F .G.S., Proceedin s of G t Sdbman's Journal N 3g0 eol. Soc., No, 12 1829 ' 0• ' p. 303, ' • |