These curious round tables, on which the merchants of this ancient city formerly made their payments, and wrote their letters, &c., are now used by the newsmen, who here sell the daily journals, &c. In times of popular excitement, they have been sometimes used as pedestals, whence mob-orators, and candidates for parliamentary honours, have harangued the populace. J. R. W. _Grimsdyke or Grimesditch_ (Vol. iv., pp. 192. 330.).--There is a hundred in Norfolk called Grimeshoe or Grimeshow, of which Blomefield, in his History, vol. ii. p. 148., says: "It most probably derives its name from _Grime_ and _hoo_, a hilly champaign country. This Grime was (as I take it) some considerable leader or general, probably of the Danes, in this quarter; and if he was not the _præsitus comitatus_, or _vicecomes_, that is, the shire reeve or sheriff, he was undoubtedly the _Centuriæ præpositus_, that is, the hundred-greeve; and, as such, gave the name to it, which it retains to this day." Near this is a curious Danish encampment, with a number of pits and tumuli, called _Grime's Graves_, from the aforementioned Grime. These are about two miles east of the village of Weeting, on a rising ground. On the west side of the village is a bank and ditch, extending several miles, called the Fen-dyke or Foss. The encampment contains about two acres, and is of a semicircular form. There are numerous deep pits dug within it in the quincunx form, and capable of concealing a large army. There are also several tumuli, one in particular of a long shape. The usual opinion respecting these remains is, that it was the seat of great military operations between the Saxons and Danes. E. S. TAYLOR. _Derivation of "Æra"_ (Vol. iv., p. 383.).--With regard to the derivation of _Æra_ (or _Era_). I have always been accustomed to explain the derivation of _Æra_ or _Era_ thus:--that it is a term transferred from the [brazen] tablets, on which the records of events were noted, to the events themselves, and thence to the computum, or fixed chronological point from which the reckoning proceeds. My difficulty here has been to find sufficient instances of the use of brass in ancient times for these purposes. Brass was the material on which laws, &c. were commonly registered: but the fasti at present discovered, as far as I can learn, are engraven on marble; as, for instance, the Fasti Capitolini, discovered in the Roman Forum in 1547, and the fragments afterwards brought to light in 1817, 1818. Isidore of Hispola, in the eighth century, in his _Origines_, gives this derivation: "Æra singulorum annorum constituta est a Cæsare Augusto, quando primum censum exegit. Dicta autem Æra ex eo, quod omnis orbis æs reddere professus est reipublicæ."