My life : a record of events and opinions - Wallace-online.org

RESIDENCE IN SOUTH WALES 89bounded by a very dangerous precipice on the sidetowards Brecon, where there is a nearly verticalslope of craggy rock for three or four hundred feetand a very steep rocky slope for a thousand, so thata fall is almost certainly fatal, and several such accidentshave occurred, especially when parties of youngmen from Brecon make a holiday picnic to thesummit.What strikes the observant eye as especiallyinteresting is the circumstance that these two triangularpatches, forming the culminating points ofSouth Wales, both slope to the south-west, and bystooping down on either of them, and looking towardsthe other, we findthat their surfaces correspond soclosely in direction and amount of slope, that theyimpress one at once as being really portions of onecontinuous mountain summit. This becomes morecertain when we look at the whole mountain mass, ofwhich they form a part, known as the " Fforest Fawr,"or great forest of Brecknock. This extends abouttwenty miles from east to west and ten or twelvemiles from north to south ; and in every part of itthe chief summits are from 2000 to 2500 feet high,while near its western end, about twelve miles fromthe Beacons, is the second highest summit. Van Voel,reaching 2632 feet. Most of these mountains haverounded summits which are smooth and covered withgrassy or sedgy vegetation, but many of them havesome craggy slopes or precipices on their northernfaces.Almost the whole of this region is of the Old RedSandstone formation, which here consists of nearlyhorizontal strata with a moderate dip to the south ;and the whole of the very numerous valleys withgenerally smooth and gradually sloping sides which