Culture Secretary Ben Bradshaw said:
"Any competition that pits the Apollo 10 spacecraft against Stephenson's Rocket, and the DNA double helix against the Model T Ford, is bound to provide talking points aplenty.
"The public's choice of the X-ray machine as the winner is testament to our insatiable curiosity to find out how things work."
The poll was conducted as part of the Science Museum's events to mark its centenary. The 10 objects form a special Centenary Journey trail through the museum galleries.