When the written matter on these tablets was no longer wanted, a fresh surface for writing was prepared either by smoothing down the wax with the handle of the stilus, or else by scraping it off and pouring in a fresh supply. This is mentioned by Ovid (_Ar. Am._ I. 437); "cera ... rasis infusa tabellis[6]." These tablets were sometimes called briefly _cerae_; the phrases _prima cera_, _altera cera_, meaning the first page, the second page. The best sorts of wooden writing-tablets were made of box-wood, and hence they are sometimes called [Greek: pyxion]. In addition to the holes along one edge of each tablet through which the cord or wire was passed to hold the leaves together and to form the hinge, additional holes were often made along the opposite edge in order that the letter or other writing on the _tabulae_ might be kept private by tying a thread through these holes and then impressing a seal on the knot. Plautus (_Bacch._ IV. iv. 64) alludes to this in mentioning the various things required to write a letter, _Effer cito stilum, ceram, et tabellas et linum._ In some cases wooden tablets of this kind were used without a coating of wax, but had simply a smooth surface to receive writing with ink and a reed pen. Many examples of these have been found in Egypt. The writing could be obliterated and a new surface prepared by sponging and rubbing with pumice-stone. _Whitened boards._ Among the Greeks wooden boards, whitened with chalk or gypsum, were often used for writing that was intended to be of temporary use only. Charcoal was used to write on these boards, which were called [Greek: leukômata] or [Greek: grammateia leleukômena][7]. Public advertisements and official announcements were frequently written in this way and then hung up in a conspicuous place in the _agora_ or market-place of the city. _Sacred accounts._ Thus some of the inscriptions of the fourth century B.C., found at Delos mention that every month a [Greek: leukôma] was suspended in the _agora_, on which was written a statement of the financial management and all the expenses of the Temple of the Delian Apollo during the past month. Finally, at the end of the year, an abstract of the accounts of the Temple was engraved as a permanent record on a marble _stele_. This was also the custom with regard to the financial records of the Athenian Parthenon, and probably most of the important Greek temples. In connection with the sacred records, the Delian inscriptions mention, in addition to the [Greek: leukômata], other forms of tablets, the [Greek: deltos] and the [Greek: pinax], and also [Greek: chartai] or writings on _papyrus_; manuscripts of this last kind will be discussed in a subsequent section[8]. _Late survivals._