This parish is situated on rocks of the calcareous series, which are for the most part like those of Laneast; but where Trewen joins Alternun, bounded only by the small river Inney, some strata occur which deserve more particular notice. It has already been stated, that on the opposite side of this stream, a potstone or ollareous serpentine occurs; on the Trewen side a talcose schist first appears, which is followed by a calcareous schist, with its surface talcose and glossy, resembling the slate at Cotele on the Tamar. This slate gradually passes into a compact limestone, which is light-coloured and talcose, especially in such parts as come in contact with masses of hornstone diffused through the mass. This limestone is quarried and burnt on the spot, but after the selection of such portions as abound with calcareous spar. TRURO. HALS. Truro is situate in the hundred of Powder, and hath upon the north Kenwen, east Clement’s, south an arm of Falmouth Harbour, where twice a day, upon spring tides, the sea makes its navigable flux and reflux to the walls, keys, and streets thereof. In the Domesday Book 1087, this place was taxed under the appellations of Trewret and Treured, which shews that it then consisted of two privileged manors or jurisdictions, viz. the borough of Trewret and the manor of Treured, now known, and still distinguished, by the names of the borough and manor of Truro, under the like circumstances. In the Inquisition of the Bishops of Lincoln and Winchester 1294, into the value of Cornish Benefices, Ecclesia de Trewroe, in decanatu de Powdre, was rated liii_s._ iv_d._ By the Charter of its incorporation from King John, the town was incorporated by the name of Burgus de Trewrow. In Wolsey’s Inquisition 1521, this church’s revenues were valued at £16. The patronage formerly in Bodrigan or Trenowith, now Edgecumb. The incumbent Pagett; and the borough of Truro was rated to four shillings per pound Land Tax for one year, 1696, £186. 7_s._ That here was a Christian free chapel before the Norman Conquest I doubt not, implied in the word Trewrow, now a Rectory Church; in the glass windows of which, the north side thereof, is yet extant the arms of John Earl of Cornwall, who succeeded to the Crown of England 1199, and was made Earl of Cornwall by his father King Henry II. at nine years old (though he had not the possession thereof till the time of Richard I. 1190, which was but a hundred and twenty-four years after the Norman Conquest, and but one hundred and three years after the Conqueror’s death); which arms were: in a field Ruby, three leopards in pale passant gardant Tophaz, over all a bend Sapphire, which leopards are now called, and metamorphosed in the blazon of the Kings of England’s arms to lions, as it is testified by Nicholas Upton, who wrote his Book of Heraldry 1440, whose words be these: “Monsieur Johanes Roy d’Angleter, port de Gowles, ove trois lyopers d’Or.”