danger-the mind and purpose of man contending with the conditions and forces of nature; conditions changing slowly at first, but, as knowledge begat knowledge, with ever-increasing speed. Looking back over the path man has traveled, we find many milestones marking the way toward safety, all bearing witness to the same purposeconservation of life. Standing even after the passing of the ages, we find the cave of prehistoric man; the multiple abode of the cliff dweller; the feudal castle, and the block housemute evidence of the common thought -safety. As the social order of civilization changed and became more and more complex, the problem of safety changed. To meet the mass element projected into the problem, we have applied science ("the arrangement and correlation of knowledge") and engineering ("the art of organizing and directing men and controlling the forces and materials of nature for the benefit of the human race"). These have proven to be man's most effective agencies of conservation. As industries developed, multiplied and expanded into individual magnitude, an ever-increasing burden was placed upon man-power. The engineer responded to the call; developed engines and machines; lifted man to a higher plane; multiplied his powers a thousandfold, and created a new era. An era, however, fraught with many new and unforeseen hazards as byproducts of progress; and again man called upon the engineer to protect him against the hazards incident to these very engines and machines that had contributed so much toward the in