Not all such reliefs, however, are signs of shops. Near the Porta Marina (at the northwest corner of Insula VII. xv), a tufa block may be seen near the top of the wall, showing a mason's tools in relief; above it is the inscription, _Diogenes structor_, 'Diogenes the mason.' This is not a sign--the inscription can hardly be read from below; it is, moreover, on the outside of a garden wall, with no house or shop entrance near it. It is rather a workman's signature; Diogenes had built the wall, and wished to leave a record of his skill. * * * * * In antiquity the miller and the baker were one person. We rarely find in Pompeii--and then only in private houses--an oven without mills under the same roof. There were many bakeries in the city. The portion already excavated contains more than twenty, each of them with three or four mills; bread was furnished, therefore, by a number of small bakeries rather than by a few large establishments. [Illustration: Fig. 219.--Plan of a bakery. 8. Atrium. 15. Mill room. 16. Stable. 17. Oven. 18. Kneading room. 19. Storeroom.] The appearance of a bakery to-day, with its mills and its large oven, may be seen in Fig. 218. The arrangements can more easily be explained, however, from the plan of another establishment, one of the largest, in the third Insula of Region VI. (Fig. 219). Entering from the street through the fauces, we find ourselves in an atrium of simple form (8) with rooms on either side; the tablinum (14) is here merely an entrance to the mill room (15). In the corner of the atrium is a stairway leading to a second story, which was particularly needed here, because the living rooms at the rear were required for the bakery; the floor of the second story was supported by brick pillars at the corners of the impluvium, joined by flat arches. The four mills (_b_), were turned by animals; the floor around them is paved with basalt flags like those used for the streets. In the same room, at _d_, were the remains of a low table; at _c_ there is a cistern curb, with a large earthen vessel for holding water on either side, while the wall above was ornamented with a painting representing Vesta, the patron goddess of bakers, between the two Lares. On one side of the oven (17) is the kneading room (18), on the other the storeroom (19). The room at the left (16) is the stall for the donkeys that turned the mills. [Illustration: Fig. 220.--A Pompeian mill, without its framework.]