. The Quarterly journal of the Geological Society of London. ing to 226 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 7, Capt. Moody, about 1920 acres of surface. It at first flows througha narrow and uncultivated ravine, which, three miles above the smalltown of Holmfirth, opens out into a narrow valley. This valley hasalways been subject to occasional floods, arising, however, fromnatural causes : one of the most disastrous occurred in 1777. Thebottom of the valley shows beneath the turf an accumulation, severalfeet thick, of local gravel and rolled fragments of rocks. In someplaces debris of
. The Quarterly journal of the Geological Society of London. ing to 226 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 7, Capt. Moody, about 1920 acres of surface. It at first flows througha narrow and uncultivated ravine, which, three miles above the smalltown of Holmfirth, opens out into a narrow valley. This valley hasalways been subject to occasional floods, arising, however, fromnatural causes : one of the most disastrous occurred in 1777. Thebottom of the valley shows beneath the turf an accumulation, severalfeet thick, of local gravel and rolled fragments of rocks. In someplaces debris of this description overlies 2 to 3 feet of imperfect peatymatter, which again appears to repose on similar detrital accumula-tions. This drift, however, is much water-worn, and does not seemto contain any masses of rock at all approaching to the dimensions ofthose transported by the late flood. The following outline map shows the course of the stream and thesituation of the principal places referred to. Fig. I.—Course of the River Holme and Bigley Fig. 2.—(See p. 229.) Between 1840 and 1844, an embankment 9Q feet high (but whichafterwards subsided to 87 feet), about 480 feet wide at base, 16 feetat top, and 340 feet in length, was thrown across the valley of theDigley, three miles above Holmfirth. By this means an artificial lake,known as the Bilberry Reservoir, about a quarter of a mile long,300 to 400 feet broad, with a surface of rather more than 11 acres,and in the centre from 70 to 80 feet deep, was formed. It was cal-culated that, when full, this reservoir held 86,248,000 gallons ofwater. The dam was constructed of a wall of clay-puddle, 8 feet wideat top, and 16 feet at bottom, with a mass of the debris of the valley,consisting of earth and stones, on either side. The inner slope waspaved with squared stone, and had a base 3 to 1 ; the outer slope, abase of 2 to 1. On the night of the 4th of February last, the giving way of thisembankment caused the sad catas
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectgeology, bookyear1845
