This approach is illustrated by the following passage in the opinion of Lord Kinnear in the Scottish case of Harvie v. Robertson (1903) 5 F 338, 346, where the pursuer sought interdict against the defender from carrying on the operation of lime-burning on his land:

 "I agree entirely in what was said by Lord Adam that the question whether a proprietor complaining of such injury has a title and interest to interfere does not depend exclusively upon present injury to his land. He is entitled to take into account not only the actual inconvenience and discomfort caused to people living on the ground by noxious fumes, but also the injury to the value of the property and the prospect of using it for advantageous purposes, other than those to which it is actually applied at the moment."

      In my opinion the decision in Khorasandjian v. Bush [1993] Q.B. 727 is open to criticism because the majority who adopted the same approach as that taken in Motherwell v. Motherwell (1976) 73 D.L.R. (3d.) 62--a decision which I think, with respect, is equally flawed on this ground - failed to apply the general rule of law, noted by Peter Gibson J. at p. 745A-D, that only an owner or occupier of the property affected can maintain an action for private nuisance. The interlocutory order which was made in that case and was held on appeal to have been worded appropriately was in the widest terms. It restrained the defendant from "using violence to, harassing, pestering or communicating with" the plaintiff. It was so widely drawn that it covered the defendant's conduct wherever he happened to be when making the unwanted telephone calls and wherever the plaintiff happened to be when she received them. Its use of language demonstrates that the case was concerned with the invasion of the privacy of the plaintiff's person, not the invasion of any interest which she might have had in any land. I would be uneasy if it were not possible by some other means to provide such a plaintiff with a remedy. But the solution to her case ought not to have been found in the tort of nuisance, as her complaint of the effects on her privacy of the defendant's conduct was of a kind which fell outside the scope of the tort.

      The importance of taking a principled approach to this matter can be seen on reading some of the observations of Hardie Boys J. in Bank of New Zealand v. Greenwood [1984] 1 N.Z.L.R. 525, 530 where he said:

 "The tort of nuisance is not capable of a single comprehensive definition, and it is sufficient for present purposes to state that we are concerned with that part of it which gives a remedy for certain interferences with the occupier's use or enjoyment of his land. It may on an appropriate occasion be necessary to emphasise the distinction between this kind of case and those where the complaint is of physical damage to the land or something upon it. For in the latter, liability is probably strict, whilst in the former, it is certainly arguable that fault must be established."

With great respect, I fear that this passage overlooks the distinction between the tort of nuisance and that of negligence. I make no criticism of the decision in that case, but there is a risk of confusion if the suggestion that a remedy in nuisance may be given on a basis other than that of strict liability, within the relevant meaning of that phrase, were to be applied more generally.

      For these reasons, and for the reasons given by my noble and learned friends Lord Goff of Chieveley and Lord Hoffmann with whose speeches I have had the benefit of reading in draft and with which I am in full agreement, I also would allow the appeal of the defendants in the dust case and their cross-appeal in the television case.

      The question whether interference with television reception by the presence of the Canary Wharf Tower in the defendants' urban development area is an actionable nuisance also raises an issue of principle. The starting point is to notice that what is being complained of is--and this is not meant to suggest that the complaint of interference is in itself at all unreasonable--simply the result of building this building on the land. It is a very large building and its cladding is made of stainless steel. But it is not suggested that it was designed in that way maliciously in order to interfere with the plaintiffs' television reception. Nor is it suggested that the interference was due to any activity or inactivity on or within the building which might have been stopped or otherwise dealt with by an injunction. There are no other special features about the case, such as an allegation of breach of contract or a breach of any statutory rules. If there is an actionable nuisance here, it can only be because a remedy exists by analogy with the law relating to easements.

      The presumption however is for freedom in the occupation and use of property. This presumption affects the way in which an easement may be constituted. A restraint on the owners' freedom of property can only be effected by agreement, by express grant or--in the case of the easement of light--by way of an exception to the general rule by prescription. The prospective developer should be able to detect by inspection or by enquiry what restrictions, if any, are imposed by this branch of the law on his freedom to develop his property. He should be able to know, before he puts his building up, whether it will constitute an infringement.

      The presumption also affects the kinds of easement which the law will recognise. When the easements are negative in character--where they restrain the owners' freedom in the occupation and use of his property--they belong to certain well-known categories. As they represent an anomaly in the law because they restrict the owners' freedom, the law takes care not to extend them beyond the categories which are well known to the law. It is one thing if what one is concerned with is a restriction which has been constituted by express grant or by agreement. Some elasticity in the recognised categories may be permitted in such a case, as the owner has agreed to restrict his own freedom. But it is another matter if what is being suggested is the acquisition of an easement by prescription. Where the easement is of a purely negative character, requiring no action to be taken by the other proprietor and effecting no change on the owner's property which might reveal its existence, it is important to keep to the recognised categories. A very strong case would require to be made out if they were to be extended. I do not think that that has been demonstrated in the present case.

      There is no reported case where an easement against the interruption of the receipt of radio or television signals has yet been recognised. The closest analogy is with uninterrupted prospect, which cannot be acquired by prescription, but only by agreement or by express grant. Unless restricted by covenant the owner is entitled to put up whatever he chooses on his own land, even though his neighbour's view is interrupted. The interruption of view will carry with it various consequences. It may reduce amenity generally, or it may impede more particular things such as the transmission of visual signals to the land from other properties. That may be highly inconvenient and it may even diminish the value of the land which is affected. But the proprietor of the affected land has nevertheless no actionable ground of complaint. He must make other arrangements if he wishes to continue to receive these signals on his own property. Radio and television signals seem to me to fall into the same general category. They may come from various directions over a wide area as they cross the developer's property. They may be of various frequencies, more or less capable of interruption by tall or metal-clad structures. Their passage from one point to another is invisible. It would be difficult, if not impossible, for the developer to become aware of their existence before he puts up the new building. If he were to be restricted by an easement from putting up a building which interfered with these signals, he might not be able to put up any substantial structures at all. The interference with his freedom would be substantial. I do not think that it would be consistent with principle for such a wide and novel restriction to be recognised. If that is so for easements, then the same result must follow so far as a remedy in nuisance is concerned.

      For these reasons I also would dismiss the appeal in the television action.