ROMANO-BRITISH NORTHAMPTONSHIRE exhibit especially the second type, and the third type, if it is to be called a separate type, occurs only in the country. In size the houses vary as widely as houses in all ages. The corridor houses are as a rule the smallest, some of them measuring little more than 40 x 60 feet in length and breadth, while in the more imposing courtyard houses the yards alone are sometimes three times that area. One feature, not a prominent one, remains to be noticed — trade and industry. We should perhaps place first the agricultural industry, which produced wheat and wool. Both were exported in the fourth century, and the export of wheat to the mouth of the Rhine is mentioned by an ancient writer as considerable. Unfortunately the details of this agri- culture are almost unknown : perhaps we shall be able to estimate it « • p m 10 >o *o Fig. 3. 'lLLA, CONSISTING OF CoRRIDOR HoUSE AND TWO BLOCKS OF FaRM BulLDlNGS ROUND A Rectangular Courtyard (Brading, Isle of Wight). Room vi. is the Corridor. better when the Romano-British ' villas ' have been better explored. Rather more traces have survived of the lead mining and iron mining which, at least during the first two centuries of our era, was carried on with some vigour in half a dozen districts — lead on Mendip, in Shrop- shire, Flintshire and Derbyshire ; iron in the Weald and the Forest of Dean, and occasionally to a less extent elsewhere, as perhaps in part of Northamptonshire. Other minerals were less important. The gold mentioned by Tacitus proved very scanty, and the far-famed Cornish tin seems (according to present evidence) to have been worked comparatively little and late in the Roman occupation. The chief commercial town was, from the earliest times, Londinium (London). It was never, so far as we know, raised to municipal rank, but was nevertheless a place of X63
