Human beings, searching a century ago as now for better understanding, had no television, no radios, no telephones and no motion pictures through which to communicate. Medical science had not yet discovered the wonder drugs to end many dread plagues and diseases. One hundred years ago military men had not yet developed the terrifying weapons of warfare that we know today—not the bomber, an airborne fortress raining down death; nor napalm, that burner of all things and flesh in its path. A century ago there were no skyscraping buildings to kiss the stars and no gargantuan bridges to span the waters. Science had not yet peered into the unfathomable ranges of interstellar space, nor had it penetrated oceanic depths. All these new inventions, these new ideas, these sometimes fascinating and sometimes frightening developments came later. Most of them have come within the past sixty years, sometimes with agonizing slowness, more characteristically with bewildering speed, but always with enormous significance for our future.