This potent introduction extracts the essential and interesting facts of engineering, history, geography and shipping to give fifth and sixth grade readers some understanding of the construction and importance of the Panama Canal. Fifty two million gallons of water must be released to take a ship all the way through the Canal. Finished in 1914, after a series of abortive efforts, the Canal employs 10,000 Panamanians and and 3500 U.S. Citizens, many of them children or grandchildren of the original builders. Today measurements of aircraft carriers and battleships are dictated by the lock measurements of the Canal with its concrete walls standing 110 feet apart. Defense needs may cause the building of a broader channel which will divert some of the shipping now passing through the Canal to serve 72 trade routes.