A HISTORY OF LONDON years of the conquest."^ The output of the Mendip mines was continuous till about 170 when a decline seems to have set in, and it was not till a century later that the industry revived, in the days of Carausius and the Constantines. Though no pigs of lead have been found in the City it is quite possible that London was one of the ports from which the metal was distributed abroad; and that such were exported is shown by a specimen dating from the reign of Nero (54-68), which was found at the mouth of the Somme."* On this point the elder Pliny, writing before a.d. 79, has the following remark : We use lead (called plumbum nigrum in contrast to plumbum album = tin) for pipes and sheet-metal. It is extracted from the ground with considerable labour in Spain and through- out Gaul, but in Britain it occurs near the surface so abundantly that a law has been enacted to prevent its production beyond a certain quantity. Its use for cineraries and coffins was evidently extensive, and lengths of lead piping have been found in London, Silchester, Chester and elsewhere, while it was no doubt also used for roofing houses. Its position on a tidal river at the intersection of several Roman highways soon put London ahead of its early rival Colchester. Before the Claudian conquest Camulodunum had a mint and issued gold and silver coins of Cunobelin (Cymbeline) : later it was selected with London for the mintage of coins by Carausius (287—93) (Fig. 12), but after his death the privilege was restricted to London, where the provincial coinage bearing the mint- mark PLN or PLON, was produced under Diocletian (d. 305), Maximian, Constantius and Constantine (306—37). About the year 326 the mint was closed, but was restored by Magnus Maximus (383-8). It is possible that coins marked avgob also belong to London,"^ which bore the name Augusta in the fourth century ; and a hint as to the locality of the mint is afforded by the discovery at the Tower of a silver ingot ' from the workshop of Honorinus ' ^" in association with unworn coins of Honorius (395-423), the emperor who cut Britain adrift from the Empire. It is an interesting coincidence that the Mint is to this day in the same quarter of the City ; and it was probably here that the Treasury official of Augusta named in the Notitia Digriitatum "^^ had his head quarters in the fourth century. The position held by Londinium is indicated in other ways. In the Notitia mention is made of three praesiJes (presidents), that of Britannia prima (south of the Thames) being resident at London, while the head quarters of Britannia secunda (Wales) and Flavia Caesariensis (the Midlands and Eastern counties) were at Caerleon (Isca Silurum) and at Colchester or Lincoln respectively. Among the many inscriptions found on these sites perhaps the most important politically is the fragment from St. Nicholas Lane recording a dedication to a deified emperor and the province of Britain. Further the bronze head of Hadrian found in the Thames justifies the assumption that under that emperor (117-38) London held a foremost position in the civil ^"F.C.H. Somen, i, 334. "« F.C.H. Hants, i, 324. '"' Nat. Hist, xxxiv, 1 7, s. 49. "* The London mint is discussed in Numis. Chron. (Ser. 2), vii, (1867), 57, 321, pis. iii, Iv; (Ser. 3), xx, 147, pis. iv, V ; Jrch. Jourrt. xxiv, 159. The letters oB of the mint-mark denote the quality of the metal ; and the letter p is probably for prima {pfficina). Other mint-marks attributable to London are given in tiumis. Chron. (Ser. 4), vii, 60-3. "' This is the probable reading of the stamp : see Topog. Index. '■'^ Booking's ed. p. 48 : praepositus thesaurorum Augustensium in Britannis. 40
