It would seem that the rediscovery of the Catacombs was providentially reserved to a period especially adapted for their profitable study. In the fullness of time, when the great Reformation was emancipating the minds of men from the trammels of superstition, and long-venerated beliefs and usages were being compared with the still older primitive faith and practice, this marvellous testimony of the purity, simplicity, and piety of the early church was unveiled. These Christian evidences, which have no parallel save in the sacred scriptures themselves, after having been sealed up during the dark ages of ignorance and superstition, were brought to light in a period of intellectual quickening and revived classical learning, which stimulated the minds of men to the study of the past and to the rescue from oblivion of the priceless remains of antiquity. The newly-invented printing-press and the engraver’s burin preserved the record of much that has since perished; and Roman archæologists, seeking in the monuments of antiquity for corroboration of papal doctrine and practice, brought to light the disproof of their existence in the early ages of the church. A rejection of this testimony would invalidate _all_ monumental evidence, whether sacred or secular, concerning the past. The rediscovery of this subterranean city took place in the year 1578. 151 Some labourers digging _pozzolana_ in a vineyard on the Salarian Way came suddenly upon an ancient cemetery,[257] with its paintings, inscriptions, sarcophagi, and graves. The event produced a profound sensation in Rome. The city was amazed, says Baronius, who himself examined and described the newly-discovered Catacomb, at finding beneath her suburbs long-concealed Christian colonies.[258] These ancient shrines became again favourite places of devotion. Here, among others, St. Charles Borromeo and St. Philip Neri spent whole nights in prayer. The earliest systematic explorers of the Catacombs were Alfonso Ciacconio, a Spanish priest, and Philip de Winghe and Jean l’Heureux,[259] two Flemish laymen. The voluminous MSS. and drawings of the two former, however, were never published, and they lie buried in those vast cemeteries of literature, the libraries of Rome, Naples, Brussels, and Paris. The valuable MS. of l’Heureux, the result of twenty years’ labour, although ready for publication, and even licensed for printing, in 1605, remained unprinted for two centuries and a half, when it was given to the public by Padre Garrucci under the appropriate title of _Hagioglypta_.[260] Such a lengthened period between licensing and publication is probably unparalleled in literary history.