Travers Twiss,
The Oregon Territory, Its History and Discovery
“ What lapse of time is requisite to found a valid title by prescription has not been definitely settled. The law of nature suggests no rule. Where, however, the claimant cannot allege undoubted ignorance on his part, or on the part of those from whom he derives his right, or cannot justify his silence by lawful and substantial reasons, or has neglected his right for a sufficient number of years as to allow the respective rights of the two parties to become doubtful, the presumption of relinquishment will be established against him, and he will be excluded by ordinary prescription. ”
