The foregoing examples of transformation serve to place before the reader some idea of the general nature and function of an incepting energy influence. But for the broadest aspects of the latter agencies it is necessary to revert once more to celestial phenomena. As already indicated in the General Statement, the primary transformations of planetary axial energy are stimulated by certain agencies inherent to, and arising from, the central mass of the system. These energy agencies or effects operate through space, and are entirely passive in nature. They are in no way associated with energy transmission; they are merely the determining causes of the energy-transforming processes which they induce, and do not in the least affect the conservative energy properties of the planetary masses over which their influence is cast. Of the precise number and nature of such influences thus exerted by the primary mass we can say nothing. The energy transformations which are the direct result of their action are so extensive and so varied in character that we would hesitate to place any limit on the number of the influences at work. Some of these influences, however, being associated with the phenomena of everyday experience, are more readily detected in action than others and more accessible to study. It is to these that we naturally turn in order to gain general ideas for application to more obscure cases. Of the many incepting influences, therefore, which may emanate from the primary mass there are three only which will be dealt with here. Each exerts a profound action on the planetary system, and each may be readily studied and its working verified by the observation of common phenomena. These influences are respectively the gravitation, the thermal, and the luminous fields.