Alexander BacheDied 17 Feb 1867 at age 60 (born 19 Jul 1806).Alexander Dallas Bache was an American physicist who was Ben Franklin's great grandson and trained at West Point. Bache became the second Superintendent of the Coast Survey (1844-65). He made an ingenious estimate of ocean depth (1856) by studying records of a tidal wave that had taken 12 hours to cross the Pacific. Knowing that wave speeds depend on depth, he calculated a 2.2- mile average depth for the Pacific (which is within 15% of the presently accepted value). As President of the National Academy of Sciences, Bache secured greater government involvement in science. Through the Franklin Institute he instituted boiler tests to promote safety for steamboats.