In a lecture upon the "Sovereignty Over the Air" delivered before the University of Oxford on October 26th, 1912, by Sir H. Erle Richards, Professor of International Law and Diplomacy, after stating that the true reason of the law which gives to states the sovereignty over the belt of the high seas adjoining their coasts and over the bays and other indentations on their shores, is that such rights are necessary for the preservation and protection of their territories, he claims that the same principle requires that states should have full sovereignty over the air above them, for the presence of any vessel overhead is a source of danger to persons and property beneath. He claims that the English Aerial Navigation Act of 1911 is a direct assertion of sovereignty over all air vessels, irrespective of altitudes, and supports himself upon the proposition that the passage of an aeronaut at any height over the land of another constitutes a trespass, citing the views of some of the judges in the cases of Pickering v. Rudd (1815), 4 Camp. 219, 220; Kenyon v. Hart (1865, 6 B. & S. 249, 252; Wandsworth Board of Works v. United Telephone Co. (1884), L. R. 13 Q. B. 904, and Finchley Electric Light Co. v. Finchley Urban Council (1903), 1 Ch. 440. Indeed, he claims that this is also the private law of other countries as well. Since the private citizen has an unlimited ownership, by analogy of the state should possess an unlimited jurisdiction. He contests the idea that there is any right of innocent passage through the air at any height and points out that the range of cannon is now sufficient to cover any height of the air practicable for the purposes of navigation. As a result of this position he maintains that in case of war it would be the duty of neutral states to hinder the operations of belligerents above their territories, including the passage of air-ships of war.

In an interesting article by H. B. Leech upon "The Jurisprudence of the Air" in the Fortnightly Review of August, 1912, the author points out the difficulty which the use of airships will create in making a blockade effective. No one is under obligation to regard a blockade unless it is effective and the necessity of having an air fleet to cut off access to beleaguered cities would be a new reason for equipping ships of war with

aeroplanes. Mr. Leech favors the view that that portion of the atmosphere which is within the range of artillery situated upon the ground should be regarded as similar to the territorial waters of the state and subject to the servitude of innocent passage of air-ships of all nations, while aerial heights beyond the reach of artillery should be regarded like the high seas and free alike to air-ships of all nations. The difficulty in the application of this view is that when the aviator soars so high as to be beyond the reach of artillery, the air would be too thin for him to breathe, to say nothing of the intense cold of the upper heights.

Upon the general subject of the law of the air the most complete work in English is one so entitled by Dr. Hazeltine of the University of Cambridge, published in 1911. In regard to the right of ownership of landowners usque ad coelum, while admitting that various dicta would indicate that this right exists, he concludes that the actual decisions of the courts go no further than to hold that the landowner has a proprietary right in the lower stratum of the air-space, a violation of this proprietary right giving the landowner the action of trespass (69). He attaches considerable importance to the suggestion of Sir Frederick Pollock, already mentioned, that the scope of possible trespass might be limited by that of effective possession, and that as regards the air-space above this stratum effectively possessed, the remedy of the landowner might well be nuisance rather than trespass (73). In regard to the foreign law, he notes that the German civil code and the civil code of Switzerland do not allow the landowner to object to acts which he has no interest in preventing (77). As to the liability of an aeronaut for acts producing damage without negligence on his part, he favors the doctrine of absolute liability just as in case of keeping wild animals (84). This was the doctrine upheld by Dr. Sarfatti at the Verona Congress and adopted by Governor Baldwin (86). Dr. Hazeltine opposes the use of the atmosphere over neutral states for the passage of belligerent aerial craft in order to reach the air-space beyond, applying the same principle as in case of the marching troops (139), a doctrine for which there is certainly a great deal to be said,

although as we shall see, it is contrary to the views of M. Fauchille.

Turning now to authorities in German, one of the earliest treatises, or perhaps I should say pamphlets, upon this subject is entitled "Das Luftschiff in Internen Recht und Völkerrecht" (The Air-Ship in Local Law and International Law) by Dr. F. Meili, a Professor in the University of Zurich and a member of the Institute of International Law, published at Zurich in 1908. He tells us that on July 1, 1908, one of Count Zeppelin's dirigible air-ships appeared in the atmosphere of Zurich and in fact in the immediate neighborhood of the author's house. This interesting stranger "lone wandering but not lost" made an appeal to his juristic conscience so that he straightway undertook to find a place for the air-ship in the law. He thereupon enters upon a discussion of the relation of the air-ship to the state, its position in private law, and even discusses the matter of procedure and the criminal law as applicable to such craft, concluding with a chapter from the standpoint of International Law in which he contends for the position of the freedom of the air, limited by the necessity of protection for the underlying state. As an appendix to this work is printed the project of M. Fauchille, the versatile editor of the Revue Générale de Droit Internationale Publique, for the judicial regulation of air-ships, which was presented by this distinguished publicist to the Institute of International Law, of which he is a member, and will be found in the proceedings of that eminent body in Vol. 19 at page 19. This project is both interesting and ingenious, although it may be considered to some extent in advance of the times, as for example, in Article 18 in which he provides what shall be the nationality of children born on board an air-ship. Dr. Meili is in hearty accord with the conclusion of the Institute of International Law in its session in Ghent in 1906, Vol. 21, pages 327-329, in its first article where it is stated: "The air is free. States have over it in time of peace and in time of war only such rights as are necessary for their protection.”

(The later draft by M. Paul Fauchille of an international convention upon the legal regulation of air-ships in sixty-three articles will be found contained in the second volume of the

Revue Juridique Internationale de la Locomotion Aérienne at page 206.)

Professor Zitelmann's article upon "Luftschiffahrtrecht" will be found in the 19th volume of the Zeitschrift für Internationales Privat-und Offentliches Recht at page 458 (1909), and was an address delivered before the international air-ship exposition at Frankfort. This contains one of the most powerful arguments in favor of the view of the absolute sovereignty of the state over the air-space within its frontiers. After reviewing the previous literature on the subject, in which he calls attention among other things, to the novel work of a Dalmatian lawyer, Pappafava, upon the powers of a notary upon the land, upon the water and in the air, published in 1901, Zitelmann points out the distinction between the air and the space which the air occupies and that it is only the latter which we have to consider. This is fundamental, for while a state cannot control the air, it can from below dominate the space in which the air exists. He shows the impossibility of making any horizontal division of the air for purposes of navigation and that the concern of jurisprudence is only with so much of space as is subject to the use of man. He maintains that the air is free only over unoccupied territory and over the open sea. He says:

"It is most to be desired that in its future international dealings the German Empire should place itself with entire decision upon this standpoint which is the only one that permits it to remain master in its own house and to provide for its own safety as it shall think right.”

The argument bases itself upon the property rights of the landowner both above and below the surface. Since the state recognizes the rights of the private owner above the surface it must have complete sovereignty to protect them. He holds that it is impossible to conceive that a battle in the air should be permissible above neutral territory, on account of the dangers to the neutral state. A state has a complete right to exclude aliens. From the principle of full sovereignty over the air he solves the various cases of international private law or conflict of laws which would arise in case of air-ships. For legal purposes he brings the aviator down to the ground. So far as

private law is concerned, his opinion is that established principles can easily be extended to cover any cases likely to arise. He advises hesitation in applying to aerial navigation the principles of the law of the sea rather than those of the ordinary law of the country. He, however, does not allow to the owner of land the right to forbid the passage of air-ships at a reasonable height. Where an aviator is compelled by necessity to make a landing he should bear all the resulting expense, otherwise he thinks an aviator should not be liable for damages except for negligence, with an exception in case where he does an act which he is bound to know is likely to produce injury such as for example emptying ballast. He quotes the proud proverb of Bremen "It is necessary to navigate, it is not necessary to live." He would not hold the aviator liable for injuries done to land for which he is in no wise to be blamed or in case of injuries due to accident, and does not agree to the proposition that the aviator should be liable to the owner of a piece of land upon which he has not alighted because of the damage done by curious crowds in running to his landing place. If a man is to be liable for drawing a crowd, no famous person dare show himself in the street.

Reference should also be made to the article by Dr. Grünwald upon the air space in its legal relation to the parts of the earth underneath, in 24 Archiv. für Offentliches Recht 190 (1909) supporting the doctrine of the sovereignty of the underlying state but excepting the right of innocent passage in favor of air-ships.

The new Swiss Civil Code is the only one which has been promulgated since the discovery of aviation, and it is interesting to note that by Article 667 the property of a landowner above and below the soil is confined to the limits within which he has an interest in its use. This principle already existed in the Civil Code of the Canton of the Grisons, article 185 dating from 1862. It is said that the limitation in the Swiss Code had nothing to do with aerial navigation.

In regard to the French literature upon the subject, which is very copious, let it suffice to cite the elaborate article by M. Paul Fauchille entitled "Le Domaine Aérient et le Régime Juridique des Aérostats" in 8 Rev. Gén. de Droit Int. Pub. 414