There is, however, another cause why rude splinters of flint |284| should accompany Roman remains, especially in the case of villas in country districts, for the _tribulum_, or threshing implement employed both by the Romans and other ancient civilized nations, was a “sharp threshing instrument having teeth,”[1263] in most cases of flint. Varro[1264] thus describes the _tribulum_:—“Id fit e tabulâ lapidibus aut ferro exasperatâ, quæ imposito auriga aut pondere grandi trahitur jumentis junctis ut discutiat e spicâ grana.” Another form of the instrument was called _traha_ or _trahea_. In the East, in Northern Africa, Spain, Portugal, Madeira, Teneriffe, and probably other parts of the world, threshing implements, which no doubt closely resemble the original _tribula_, are still in use. The name is still preserved in the Italian _trebbiatrice_, the Spanish _trilla_, and the Portuguese _trilho_, but survives, metaphorically alone, in our English _tribulation_. In Egypt their name is _nureg_, and in Greece ἁλωνίιστρα, from ἁλωνία, a threshing-floor. Drawings of various _tribula_ have been given by various travellers,[1265] and the implements themselves from different countries may be seen in the Christy Collection and in the Blackmore Museum. They are flat sledges of wood, five to six feet in length, and two or three in breadth, the under side pitted with a number of square or lozenge-shaped holes, mortised a little distance into the wood, and having in each hole a flake or splinter of stone. I have seen them in Spain mounted with simple pebbles. In those from Madeira the stone is a volcanic rock, but in that from Aleppo—preserved in the Christy Collection,[1266] and shown in Fig. 194—each flake is of cherty flint and has been artificially shaped. Occasionally there are a few projecting ribs or runners of iron along part of the machine, but in most instances the whole of the armature is of stone. As each _trilho_ is provided with some hundreds of chipped stones, we can readily understand what a number of rough flakes might be left in the soil at places where they were long in use, in addition to the flakes and splinters which for centuries have been used for striking a light. [Illustration: Fig. 194—Tribulum from Aleppo.]