Other
Eco Usa: Index of State Superfund Sites
Choose a state and get information on all of the toxic waste sites within that state individually. External links on each state's page may no longer work but the list of sites is there and can be found through a Google search.
Other
National Physical Laboratory: The History of Length Measurement
This resource provides historic information on length measurement in the United Kingdom. Click on the topics on the left toolbar of the article to find out more information.