This immunity from attack, secured by the monasteries, was due often, and perhaps chiefly, to the fact of their secluded situations and to the strong defenses of resisting masonry which made subjection and pillage difficult and profitless. The convent of St. Catharine, where Dr. Tischendorf discovered the peerless Sinaitic Manuscript of the Bible in 1859, is an example and illustration. This monastery was perched, as it were, on the precipitous slopes of Mt. Sinai at an altitude of full 5,000 feet above the level of the sea; and, until recently, the only manner of access beyond its solid, massive, and centuries-old masonry, was by means of a crude and primitive "lift" consisting of a chair and rope, controlled by the inmates and operated by a windlass and drum within and above. By this appliance all visitors were "elevated" some twenty or twenty-five feet from its base to the main entrance of the monastery. This arrangement safeguarded the occupants and the contents of this religious stronghold from risk of robbery and violence. These religious houses furnished even greater security by their position and isolation and were generally respected by the fiercest invaders. The safety of the monks--of peaceful occupation and mien--and of their possessions--almost wholly literary, even in the periods of disorder and violence--was often due to the supposed sacredness of the roofs under which they were sheltered. And even when these asylums were not respected but seized and plundered, the books which they treasured had little or no value in the eyes of the ignorant and hostile invaders, or were hidden away in recesses of the monasteries beyond the reach of prying eyes. And even when the manuscripts of a single monastery, or the monasteries of a given region, were all destroyed, untold numbers of copies--and largely duplicate copies--by reason of their previous extensive dispersion throughout wide areas and secluded regions, were preserved elsewhere to be again brought to light in more favored times, and, finally, at the revival of learning, which awaited the coming of the printing-press.