On the 16th of March 1711, some workmen, digging a burial crypt for the archbishops of Paris under the choir of Notre Dame, came upon a wall, six feet below the pavement, which contemporary antiquarians believed to be the wall of the original Christian basilica over which the cathedral was built, but which modern authorities affirm to have been part of the old Gallo-Roman wall of the Cite. In the fabric of this wall the early builders had incorporated the remains of a temple of Jupiter, and among the _debris_ were found the fragments of an altar raised to Jove in the reign of Tiberius Caesar by the _Nautae_, a guild of Parisian merchant-shippers, and the table of another altar on whose foyer still remained some of the very burnt wood and incense used in the last pagan sacrifice. The mutilated stones, with their rude Gallo-Roman reliefs and inscriptions,[13] may be seen in the Frigidarium of the Thermae, the old Roman baths by the Hotel de Cluny, and are among the most interesting of historical documents in Paris. The Corporation of _Nautae Parisiaci_, one of the most powerful of the guilds, among whose members were enrolled the chief citizens of Lutetia, who dedicated this altar to Jove, were the origin of the Commune or Civil Council of Paris, whose Provost[14] was known as late as the fourteenth century as the _Prevot des Marchands d'Eau_. Their device was the _Nef_, or ship, which is and has been throughout the ages, the arms of Paris, and which to this day may be seen carved on the vaultings of the Roman baths. [Footnote 13: On the former may still be read: TIB ... CAESARE AVG. IOVI. OPTVM ... MAXSVMO. ARAM. NAVTAE. PARISIACI PVBLICE. POSIERVNT.] [Footnote 14: Not to be confounded with the Royal Provost, a king's officer, who in 1160 replaced the Capetian viscounts. The office was abolished in 1792.]