"If you had visited one of the navy yards, a shipyard or any place where big work in iron and steel was being carried on as short a time as three years ago, you would have seen a man sitting for hours sawing away on the end of a steel beam, for instance, trying to cut it down to the required length. He would dull many saws, use a great deal of energy, and an appalling amount of the most valuable thing in the world--time. Again, you would have seen them welding pieces of iron and steel by the old blacksmith method, or riveting other pieces that could not be joined by heating them and pressing them together. "To-day you would see fewer of these processes because autogenous welding and cutting by the powerful little oxy-acetylene torches is revolutionizing certain methods of working with metals. Instead of squatting at the end of the beam and sawing away like an old-fashioned carpenter, the modern iron worker takes up his little torch, turns a valve in the handle and concentrates the flame on the steel beam that he wishes cut. Almost instantly a shower of sparks on the under side of the beam shows him that the flame has burned its way through. Then he slowly moves the flame along the line where he desires to cut and the trick is done." Illustrating with his own little laboratory torch, the scientist continued his explanation, saying that cutting is only one of the many uses to which this modern invention in steel working is put. Not quite so spectacular but every bit as useful is the autogenous welding by means of these magic wands. Welding metals has ever been more or less unsatisfactory. The old process of heating the two ends and then beating them together is cumbersome and practically impossible in many cases. Consequently inventors have sought other welding processes with wider application and greater facility ever since the first metal workers of earliest times forged crude chains and weapons. With this modern device two pieces of steel or other metal are brought to within a small fraction of an inch of each other and by the use of the oxy-acetylene torch and a thin strip or rod of metal are melted and fused together.