Galvanic corrosion is a process that degrades metals electrochemically. This corrosion occurs when two dissimilar metals are located in contact with each other in the presence of an electrolyte, such as salt water, forming a galvanic cell.
But the memories of that tragic day 25 years ago are still vivid to many in Edmond. On Aug. 20, 1986, gunman Patrick Henry Sherrill shot and killed 14 co-workers, wounded six and then took his own life inside the post office where he worked.
-- In 1961 Day appointed Mrs. Nancy C. Avery as acting postmaster of the Pacoima, California, Post Office  reportedly the first African American to head a first-class Post Office since the Reconstruction era. Avery was appointed to the position permanently in 1963 and served until her retirement in 1984.