LIGHTS, ANCIENT, are known to the law as the foundation of a right for which a man may prescribe over the premises of another to the unobstructed passage of light in the same degree to which it has theretofore been enjoyed by him or those whom he has succeeded in occupation. The light of day is the property of none, and cannot be granted or acquired in property by any. On the other hand, as he who acquires the fee .simple of land has a right extending ab inferis ad superos, from the earth's centre to the heights of heaven, he may prima facie build as high as he will, and dig as low as he chooses at the very verge of his domains. The user of the surface of his land therefore cannot lawfully be in any other without his consent. But if such a user exist, and is of long standing, it is for the interest of society that individuals who have gradually formed their habits and arrangements, and may have incurred expense, and founded contracts with others in accordance with this privilege of user, should not after wards be capriciously disturbed therein.
It is obvious, that a neighbour's window existing in a wall built to the verge of the adjoining domain, presupposes an access of light to it over the other's land, which he may refuse his consent to, and obstruct by buildings on his own soil. If he do not expressly dissent, and if he do not expressly grant the user for a limited time, and still the user goes on, which is the more common case, the question is whether ever there shall be a time when such user cannot be obstructed. To say that that which began in no right shall by mere length of time become a well established right recognisable in law, is too plainly untenable in point of reasoning to be asserted. Yet the convenience of society required provision to be made for such a result. The judges then, at common law, perceiving this necessity existing not without moral rectitude to justify it, surmounted the difficulty by a fiction ; they instructed the jury that from length of uninterrupted user they might presume it to have originated in an unqualified grant of the proprietor and find their verdict in his favour who claimed the continued access of light.
The length of time necessary to justify such a presumption, through uniformity of decision, until it had become a received rule, came to be twenty years. The neighbour's window after so long a time becomes an ancient light. Precision was afterwards given to the practice of the courts under this rule by an Act of Parliament, the 2 & 3 Wm. 4, c. 71, sec. 3 et seq., enacting that after 20 years' uninterrupted enjoy ment, the user becomes an indefeasible right, and nothing shall be deemed an interruption to defeat such acquisition of right, unless it has been submitted to or acquiesced in after notice of the act, and of the person authorising it, has reached the person who claims the right.
The right to the free enjoyment of light belongs in the Roman law to the class of Servitutes (easements), among which were the Serritos altius non tollendi, ne luminibus officiator, ne prospeetui officiator (' Dig.' 8, tit. 2, s. 11, 12, 15-17). The general rule is thus expressed by Ulpian : "He who shall attempt to obstruct his neighbour's lights, or to do anything else to damage them, must know that he ought to maintain the form and condition of the ancient edifices. If you and your neighbour cannot agree about the height to which buildings may be raised which you have begun to erect, you will have the privilege of having an arbiter." The stopping of a prospect is not a nuisance by the law of England, but by the Roman law there was a remedy even in that case, ne pros pedal offiriatur.