It is such a compelling legal fiction that it has its own celebrated poem, as well as a Latin maxim: Cuius est solum, ejus est usque ad coelum et usque ad inferos, literally, “Whoever holds land holds it all the way to the heavens and all the way to Hell.” As William Empson puts it in “Legal Fiction,” his 1928 poem inspired by the principle, “the law makes long spokes of the short stakes of men.”
The maxim is often said to originate with the 13th-century scholar of Roman law, Accursius, although Yehuda Abramovitch traces it to pre-Christian times among Jews, in contracts for real property. He gives an example of a contract in England, in 1280, conveying lands between Jews “from the depth of the earth to the height of the sky.” Possibly racial prejudice has obscured this Jewish provenance in Anglo-Canadian law.
Since the nineteenth century, at least, the fiction has never enjoyed this extensive application, such that sometimes it is more cautiously styled a presumption. Even in 1870, the English judge George Denman described it as a “technical rule,” albeit while finding a defendant liable in trespass because his horse bit and kicked his landlord’s mare (violated the landlord’s “air rights”) through a fence separating the two properties. Its scope has drastically been whittled down further by technological development – particularly communications infrastructure (utility poles and the like) and aviation.* At this writing, the widespread popularity of “drone” aircraft, now readily accessible to peeping Toms and break-and-enter specialists, has reinvigorated the debate as to “how low you can go” in the insistence on air and attendant privacy rights. Drones do not simply move briefly through air space like passenger jets or satellites (or bullets: see the next paragraph); they customarily hover like their namesake bees.
As early as 1815, Lord Ellenborough proved prescient about these developments in a case asking whether, in nailing a barber’s sign to the side of his premises, Rudd trespassed on Pickering’s land where the sign projected over it:
I once had occasion to rule upon the circuit that a man who, from the outside of a field, discharged a gun into it, so that the shot must have struck the soil, was guilty of breaking and entering it. . . . But I am by no means prepared to say that firing across a field in vacuo, no part of the contents touching it, amounts to a clausum fregit [i.e., a trespass]. Nay, if this board overhanging the plaintiff’s garden be a trespass, it would follow that an aeronaut is liable to an action of trespass at the suit of the occupier of every field over which the balloon passes in the course of his voyage.
Then, too, for some time there have been such considerations as occupier-owned apartments stacked atop one another in multi-storey buildings. How does Blackacre own everything above her when Whiteacre occupies 301, Greenacre 401, and so on?
As for drones, Sir Frederick Pollock proved visionary there, in his 1887 treatise on torts: “At Common Law it would clearly be a trespass to fly over another man’s land at a level within the height of ordinary buildings, and it might be a nuisance to hover over the land even at a greater height.”
Yet the maxim’s claim seems so extravagant – godlike – that Empson was moved to deflate it in his poem, concluding that such a “well fenced out real estate of mind” is, in the end, a mere candle’s shadow lit by human vanity – an arrogant pretext that we really own anything of nature’s empire, that we can just magic up our short stakes into long spokes.
* The statutory minimum cruising altitude generally for “aeroplanes [is] 1,000 feet above the highest obstacle located within a horizontal distance of 2,000 feet from the aeroplane.” Bemusingly, when Manitoba purported to tax airlines for liquor they sold while flying through the province’s airspace, the Supreme Court of Canada shot down the scheme: Manitoba v. Air Canada,  2 SCR 303.
Primary sources for this post (adapted from my forthcoming encyclopedia of legal fictions and presumptions, and constructive, deemed, and implied entities): Yehuda Abramovitch, “The Maxim ‘Cujus Est Solum Ejus Usque Ad Coelum’ as Applied in Aviation,” McGill L.J. 8:4 at 251; Stuart Ball, “The Vertical Extent of Ownership in Land” (1928), U. of Pennsylvania Law Rev., 76:6; Canadian Aviation Regulations; Ellis v. Loftus Iron Co. (1874) L.R. 10 C.P. 214; Pickering v. Rudd (1815), 4 Camp. 219; Troy A. Rule, “Airspace in an Age of Drones,” Boston U. Law Rev. (2015), 95:155 at 155-208.
For more on the Empson poem, see my The Structures of Law and Literature.