Is the navigable balloon worth improving? That is a question which is frequently asked by the general public. Now there are many of us who, with reason, feel convinced that the ultimate future solution of the problem of aërial navigation will be found to be in the body heavier than air—the aëroplane— and some will doubtless say that it is waste of time to endeavour to improve what appears only capable of improvement within only finite limits, that all our united efforts should be directed to the system which, when certain first principles are successfully applied, will not display those boundary lines to further progress which seem so apparent in the case of navigable balloons.