Curated OER
Etc: Maps Etc: Production of Phosphate, Nitrates, and Potash in Africa, 1913
"Production of phosphate, nitrates, and potash in Africa in 1913.
Curated OER
Valley City Junior Highs Water Research: Water Issues
This site talks about the nitrate and nitrogen forms that can be found and how to test for it. Includes illustrative diagrams and graphs.
Curated OER
Valley City Junior Highs Water Research: Water Issues
This site talks about the nitrate and nitrogen forms that can be found and how to test for it. Includes illustrative diagrams and graphs.
Curated OER
Valley City Junior Highs Water Research: Water Issues
This site talks about the nitrate and nitrogen forms that can be found and how to test for it. Includes illustrative diagrams and graphs.
Curated OER
Educational Technology Clearinghouse: Maps Etc: South America, 1898
A map of South America in 1898. The map shows capitals and major cities, railroads, terrain, rivers, and coastal features, and includes an insert map of the Isthmus of Panama. "The chief industries in South America are herding,...
Curated OER
Unesco: Chile: Humberstone and Santa Laura Saltpeter Works
Humberstone and Santa Laura works contain over 200 former saltpeter works where workers from Chile, Peru and Bolivia lived in company towns and forged a distinctive communal pampinos culture. That culture is manifest in their rich...