The Pennsylvania Turnpike (world's largest tunnel for cars); Gadgets for the kitchen; birth of the electron microscope; Professor Oakes' cat putter-outer; parachuting firefighters.The Pennsylvania Turnpike (world's largest tunnel for cars); Gadgets for the kitchen; birth of the electron microscope; Professor Oakes' cat putter-outer; parachuting firefighters.The Pennsylvania Turnpike (world's largest tunnel for cars); Gadgets for the kitchen; birth of the electron microscope; Professor Oakes' cat putter-outer; parachuting firefighters.
