um eius est usque ad coelum," hold that the presumption must be in
favour of sovereignty and ownership as applicable to superimposed air
space.

It is hardly necessary to observe that neither of the maxims just
mentioned was formulated with reference to problems which have only
presented themselves within the last few years. The Romans, in the
passage quoted, were thinking not of aerial space, but of the element
which fills it. The old English lawyers were preoccupied with questions
as to projecting roofs and overhanging boughs of trees. The problems now
raised are admittedly incapable of solution _a priori_, but the
difference between the two schools of thinkers is instructive, as
bearing upon the extent to which those who belong to one or the other
school would incline towards measures of precaution against abuses of
the novel art. This difference was well summed up at one of our meetings
by Professor Westlake as follows: "Conservation et passage, comment
combiner ces deux droits? Lequel des deux est la regle? Lequel
l'exception? Pour le Rapporteur (M. Fauchille) c'est le droit de passage
qui prime. Pour moi c'est le droit de conservation."

I am, Sir, your obedient servant,
T. E. HOLLAND.
Oxford, February 15 (1913).

SOVEREIGNTY OVER THE AIR

Sir,--Mr. Arthur Cohen has done good service by explaining that Great
Britain has practically asserted the right of a State to absolute
control of the airspace vertically above its territory. I may, however,
perhaps be permitted to remark that he seems to have been misinformed
when he states that the Institute of International Law has arrived at no
decision upon the subject. The facts are as follows: The problems
presented by the new art of aerostation have been under the
consideration of the Institute since 1900, producing a large literature
of reports, counter-reports, observations, and draft rules, to debates
upon which no fewer than four sittings were devoted at the Madrid
meeting in 1911. Wide differences of opinion then disclosed themselves
as to territorial rights over the air, the radical opposition being
between those members who, with M. Fauchille, the Reporter of the
Committee, would presume in favour of freedom of aerial navigation,
subject, as they would admit, to some measures of territorial
precaution, and those who, like the present writer ("il se proclame
oppose au principe de la liberte de la navigation aerienne, et s'en
tiendrait[A] plutot au principe