Tragically isolated, imprisoned in his own “self,” man has made a desperate effort to “leap beyond his shadow,” to embrace the external world. From this effort was born science, and its marvellous antennæ subtly prolong our sensations. Thus we have in places approached the brilliant raiment of reality. But in comparison with the mystery that remains the things we know are as small as are the stars of heaven compared with the abyss in which they float. Einstein has discovered new light for us in the depths of the unknown. He is, and will remain, one of the light-houses of human thought. _Printed in Great Britain by Hazell, Watson & Viney, Ld., London and Aylesbury._