BOOK IX.

411

de-silverized lead, for in this lead each centumpondium contains only adrachma of silver, when before the silver was parted from it each centumpon-dium contained more or less than three unciae of silver 50 .

The little black stones 51 and others from which tin is made, are smeltedin their own kind of furnace, which should be narrower than the otherfurnaces, that there may be only the small fire which is necessary for thisore. These furnaces are higher, that the height may compensate for thenarrowness and make them of almost the same capacity as the other furnaces.At the top, in front, they are closed and on the other side they are open, wherethere are steps, because they cannot have the steps in front on account of theforehearth ; the smelters ascend by these steps to put the tin-stone into thefurnace. The hearth of the furnace is not made of powdered earth and char-coal, but on the floor of the works are placed sandstones which are not toohard ; these are set on a slight slope, and are two and three-quarters feetlong, the same number of feet wide, and two feet thick, for the thicker they arethe longer they last in the fire. Around them is constructed a rectangularfurnace eight or nine feet high, of broad sandstones, or of those commonsubstances which by nature are composed of diverse materials 52 . On theinside the furnace is everywhere evenly covered with lute. The upper partof the interior is two feet long and one foot wide, but below it is not so longand wide. Above it are two hood-walls, between which the fumes ascendfrom the furnace into the dust chamber, and through this they escape by anarrow opening in the roof. The sandstones are sloped at the bed of thefurnace, so that the tin melted from the tin-stone may flow through the tap-hole of the furnace into the forehearth . 53

60 One drachma is about 3 ounces Troy per short ton. Three unciae are about 72ounces 6 dwts. Troy per short ton.

51 In this section, which treats of the metallurgy of plumbum candidum, “ tin,” theword candidum is very often omitted in the Latin, leaving only plumbum, which is confusingat times with lead. The black tin-stone, lapilli nigri has been treated in a similar manner,lapilli (small stones) constantly occurring alone in the Latin. This has been rendered as“ tin-stone ” throughout, and the material prior to extraction of the lapilli nigri has beenrendered “ tin-stuff,” after the Cornish.

M “ . . . ex saxis vilibus, quae natura de diversa materia composuit.” The

Glossary gives grindstein. Granite (?).

53 Historical Notes on Tin Metallurgy. The first appearance of tin lies in theancient bronzes. And while much is written upon the “ Bronze Age ” by archaeologists,we seriously doubt whether or not a large part of so-called bronze is not copper. In anyevent, this period varied with each race, and for instance, in Britain may have been muchlater than Egyptian historic times. The bronze articles of the IV Dynasty (from 3800 to4700 b.c. depending on the authority) place us on certain ground of antiquity. ProfessorGowland (Presidential Address, Inst, of Metals, London, 1912) maintains that the earlybronzes were the result of direct smelting of stanniferous copper ores, and while this may bepartially true for Western Europe, the distribution and nature of the copper deposits do notwarrant this assumption for the earlier scenes of human activity—Asia Minor, Egypt, andIndia. Further, the lumps of rough tin and also of copper found by Borlase (Tin Miningin Spain, Past and Present, London, 1897, p. 25) in Cornwall, mixed with bronze celts underconditions certainly indicating the Bronze Age, is in itself of considerable evidence of inde-pendent melting. To our mind the vast majority of ancient bronzes must have been madefrom copper and tin mined and smelted independently. As to the source of supply of ancienttin, we are on clear ground only with the advent of the Phoenicians, 1500-1000 b.c., who,as is well known, distributed to the ancient world a supply from Spain and Britain. What thesource may have been prior to this time has been subject to much discussion, and while some