As pointed out by MM. Daremberg and Saglio, _Dic. des Antiquités Grecques et Romaines_ pt. 46, p. 164, "illustrations of Greek or Roman methods of weaving are very rare, they are much reduced and in so far as the art is concerned purely diagrammatic." On the other hand if there are numerous references in the texts of classic authors, these references seem rather to obscure than elucidate the method of working. However, there are three illustrations--the Penelope loom, Fig. 31, and two Boeotian looms, one of which is illustrated in Fig. 15--quite sufficient to explain the principle of the upright loom as used with warp weights by the Greeks, and the discovery of numerous articles, considered to be the warp weights, confirm the illustration.
The principle is the same throughout, viz.: the looms are vertical, there is a warp beam on top, there are two cross rods one of which is a laze rod and _possibly_ the other is a heddle; and the warp threads are all kept taut by means of attached weights. On one of the Boeotian looms a bobbin or spool is shown. Along the top of Penelope's loom there are indications of nine pegs, on six of which balls of coloured thread have been placed, evidently for working out the designs, very much the same as shown on the rug loom in Bankfield Museum already referred to. The warp weights on this Athenian illustration are triangular in shape, and perhaps resemble the pyramidic weights found in Egypt and attributed to Roman times. Assuming these pyramids are Roman warp weights it would appear that both Greeks and Romans had vertical looms on which the warp threads were kept taut by means of weights. In one of the few clearly expressed technical classical references, Seneca speaks of the warp threads stretched by hanging weights.
In the above classical illustrations which are after all only rough diagrams, the warp weights appear to hang from a _single_ thread only, but this can not have been correct. The warp threads must have been bunched, because a single suspended thread with a tension weight immediately begins to unravel, and so loses the advantage of its having been spun, as any one can ascertain for oneself. As regards the same point on the Lake Dwellers looms, Cohausen was the first to surmise that the warp threads were bunched to receive the weight, and Messikommer proved it by practical experiment.[G]