The picture is a close-up of the compressor blades on a Pratt and Whitney J57 turbofan engine.  The J57 (or the JT3 civilian designation) was one of the early turbofan jets used for a number of significant aircraft, including theB-52 bomber, the Lockheed U-2 spy plane, and the Boeing 707 and Douglas DC-8 passenger jets, producing 11,700 pounds of thrust (17,200 pounds thrust with the after burner). The blade in the picture is one of those that make up one compressor wheel; there are 16 of those wheels ganged together on the engine.  The engines were produced from 1951 to 1965, with 21,170 units manufactured.  This engine was one of the first to be widely used in both military and commercial operations. This example has had the shell cut away to expose the inner workings and to show students the air flow path through the engine.