The Oxford Facsimiles of the Herculaneum Papyri is an indexed database of images. These facsimiles (disegni) were made when the rolls were first opened. Most of the work was carried out at Portici near Naples from 1802 to 1806 under the direction of the Rev. John Hayter and at the expense of the Prince of Wales (later George IV). In many places the drawings preserve text no longer present in the original papyri: fragments of papyrus that had become stuck to a lower layer during the unrolling process (sovrapposti) were scraped off and thus destroyed after they had been drawn, in order to reveal the letters underneath. Such fragments, and others lost through subsequent damage to the originals, are known only from these drawings.