WILTSHIRE, an inland county of England bounded N.W. and N. by Gloncesterahire, N.E. by Berkshire, S.E. by Hampshire, S.W. by Dorsetshire, and W. by Somersetahire. The county is of very com pact form, approximating to a quadrangle. Wiltshire is situated between 50° 55' and 51° 43° N. lat., 1° 29' and 2° 21' W. long. The greatest length of the county, north and south, is about 54 miles ; the greatest breadth, east and west, is 37 miles. The area is estimated at 1352 square miles, or 865,092 statute acres. The population in 1841 was 256,280 ; in 1851 it was 254,221.
Surface and Geology.—The geological formations of Wiltshire con sist chiefly of the cretaceous and oolitic series, with the intermediate beds ; in the sonth-eastern corner the chalk is covered with the tertiary formations of the chalk-basin of the Isle of Wight.
The chalk formation may be considered, from its extent, as the most striking geological feature of the county, forming as it does the extensive downs which overspread the eastern, central, and southern parts. The chalk district of Hampshire and Wiltshire constitutes the centre of the chalk formation in England, from which proceed four great branches. The first great branch is the chalk range of the Chiltern Hills, Dunstable and Royston Downs, fie, extending through Berkshire, Buckinghamshire, Bedfordshire, Hertfordshire, Cambridge shire, Essex (just the north-western corner), Suffolk, and Norfolk, acres. the Wash, reappearing in Lincolnshire and Yorkshire, and terminating in Flamborough Head; the second branch is the North Downs of Hampshire, Surrey, and Kent; the third the South Downs of Hampshire and Sussex ; and the fourth the North and South Downs of Dorsetshire, inclosing between them the trough of Poole.
The Wiltshire portion of the great central chalk district is divided into two parts by the Vale of Pewsey, where the greensand occupies the bottom of the valley, and is skirted on each side by the chalk hills. This valley extends east and west, and it may be convenient to describe the two portions into which it. divides the chalk district as the northern and southern districts: Marlborough Downs belong to the northern district ; Salisbury Plain belongs to the southern.
The northern chalk district is bounded by a line entering the county from Berkshire at the village of Bisbopston, and passes Avcbury, Eddington, or Heddington, its westernmost point, Bisbop's-Caunings, Wootton-Rivers, and Great Bedwyn, to the border of Berkshire at Great Shalbourne. The boundary may be traced throughout by a tolerably steep escarpment overlooking the surrounding country. The included chalk district is divided into two parts by the depression or valley, running east and west, through which the Kennet passes from Avebury to Iluogerford; and the northernmost of the two parts ie again divided by a valley running north and south, and drained by a small feeder of the Kennet. This valley is occupied by the chalk, as well as the higher ground on each Bide. The principal eminences are on the boundary-line of the district, and are in several instances crowned by ancient lntrenchments, or rather earthworks. The following may be enumerated :—Charlbury Hill, above Little Hinton; Beacon Hill, crowned by an ancient lntreocbment called Llddingtou Castle, above Liddington ; Barbury Hill, also crowned with an intrenehment ; Hack pen Hill, above the Winterbournes ; Oldbury Castle, an intrenehment on the summit of the hill above Cherhill, having a white horse carved on the slope beneath ; Beacon Down, above Eddington ; Roundaway Hill, above Devizes. the sceue of a severe action in the civil war of Charles I. ; with Easton Hill, St. Ann's Hill, and several other bills, which are parts of the southern escarpment overlooking the Vale of Pewsey. The northern chalk district forms an elevated platform, and is to a considerable extent uncultivated and nninclosed. In the part north of the valley of the Kennet, are Marlborough Downs, Aldbourn Chace, \Vanborough Plain, and Bishopeton Down. South of the valley of the Kennet are the King's Play Down, Pound Down, Savernake Forest, and Bedwyn and Wilton Commons.