It is an old saying that "Order is Heaven's First Law,"and like many other old sayings it contains a much deeper philosophy than appears immediately on the surface. Getting things into a better order is the great secret of progress, and we are now able to fly through the air, not because the laws of Nature have altered, but because we have learnt to arrange things in the right order to produce this result - the things themselves had existed from the beginning of the world, but what was wanting was the introduction of a Personal Factor which, by an intelligent perception of the possibilities contained in the laws of Nature, should be able to bring into working reality ideas which previous generations would have laughed at as the absurd fancies of an unbalanced mind. The lesson to be learnt from the practical aviation of the present day is that of the triumph of principle over precedent, of the working out of an idea to its logical conclusions in spite of the accumulated testimony of all past experience to the contrary; and with such a notable example before us can we say that it is futile to enquire whether by the same method we may not unlock still more important secrets and gain some knowledge of the unseen causes which are at the back of external and visible conditions, and then by bringing these unseen causes into a better order make practical working realities of possibilities which at present seem but fantastic dreams? It is at least worth while taking a preliminary canter over the course, and this is what this volume professes to attempt.