Further, even if mere lapse of time, as some think, could establish a right by prescription over public property, still the conditions absolutely indispensable for the creation of such a right are in this case absent. The conditions demanded are these: first, all jurists teach that he who sets up a prescriptive right of this sort shall have been in actual possession not only for a considerable period, but from time immemorial; next, that during all that time no one else shall have exercised the same right of possession unless by permission of that possessor or clandestinely; besides that, it is necessary that he shall have prevented other persons wishing to use his possession from so doing, and that such measures be a matter of common knowledge and done by the suffrance of those concerned in the matter. For even if - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - iis ad quos ea res pertinebat; nam etsi exercuisset semper, et quosdam exercere volentes prohibuisset semper, non tamen omnes, quia alii fuerunt prohibiti, alii vero libere exercuerunt, id quidem non sufficeret, ex Doctorum sententia. Apparet autem debere haec omnia concurrere, tum quia praescriptioni publicarum rerum lex inimica est, tum ut videatur praescribens iure suo non autem communi usus, idque non interrupta possessione. Cum autem tempus postulatur, cuius initi non exstet memoria, non semper sufficit, ut optimi interpretes ostendunt, probare saeculi lapsum; sed constare oportet famam rei a maioribus ad nos transmissam, ita ut nemo supersit qui contrarium viderit, aut audierit. Occasione rerum Africanarum in ulteriora primum Oceani inquirere coeperunt regnante Iohanne Lusitani,[146a] anno salutis millesimo quadringentesimo septuagesimo septimo. Viginti post annis sub Rege Emanuele promontorium Bonae spei praeternavigatum est, seriusque multo ventum Malaccam, et insulas remotiores, ad quas Batavi navigare coeperunt anno millesimo quingentesimo nonagesimo quinto, non dubie intra annum centesimum. Iam vero etiam eo quod intercessit tempore aliorum usurpatio adversus alios etiam omnes impedivit praescriptionem, Castellani ab anno millesimo quingentesimo decime nono possessionem Lusitanis maris circa Moluccas ambiguam - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - he had continuously exercised his right of possession, and had always prevented from using his possession _some_ of those who wished to do so, but not _all_; then, because _some_ had been prevented from exercising and _others_ freely allowed to exercise that use, that kind of possession according to the opinion of the jurists, is not sufficient to establish a right by prescription. It is clear therefore that all these conditions should be present, both because law is opposed to the prescription of public things, and in order that he who sets up such a prescription may seem to have used his own private right, not a public right, and that too by continuous possession.