Page:Aerial Flight - Volume 2 - Aerodonetics - Frederick Lanchester - 1908.djvu/11



object and scope of the present work have been stated at length in the preface to Vol. I., which appeared as recently as December, 1907; there is but little to add to this statement.

In conducting the investigations and otherwise in collecting and arranging the matter included in the two volumes now completed, the author has made an effort to do, in as thorough a manner as possible, that preparatory work which, in his opinion, should properly precede the serious and hitherto hazardous undertaking of full-scale experiment. It is in other words the author's intention to provide such foundation theory and data as to bring the problem of mechanical flight into the legitimate domain of the engineer, and to obviate in the future all need for empiricism.

The author is aware that considerable work remains to be done in the way of extension, both in the more complete elucidation of many questions relating to the flight of birds, and in the direction of the application of theory in the design of the flying-machine for aerial navigation. It has not been found practicable to deal specifically with these extensions in the present volumes, but much that is suggestive will be found embodied appropriately in the text. The passive mode of bird flight, as involved in gliding and soaring, has however been discussed at length, for it is in the study of this mode of flight that the greater part of that which is essential may be learned.