Resumen de Observing Earth--Diverting Water--Girdling the World.
Presents excerpts from articles found in previous issues of "Scientific American." Articles found in the September 1995 issue regarding geophysics, the earth's geomagnetic poles and the origin of continents on earth; Article found in the September 1905 issue regarding the government irrigation canal known as the Main Truckee Canal in Nevada; Articles found in the September 1855 issue regarding the invention of the electric telegraph by Professor Morse and a competition for the invention of the best sawing machine.
