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.