A form of apparatus often used for testing specimens of steel consists of a small electric furnace in which to heat the specimen, and a special thermo-couple pyrometer (see  Pyrometers ) for indicating the range of temperatures through which the steel passes.
Where the American Civil War Began. Decades of growing strife between North and South erupted in civil war on April 12, 1861, when Confederate artillery opened fire on this Federal fort in Charleston Harbor. Fort Sumter surrendered 34 hours later. Union forces would try for nearly four years to take it back.
On that day, the United States forever changed. While the first shots of the Civil War were fired at Fort Sumter in April 1861, the events of that fateful July 21 comprised the first true battle of the war, The First Battle of Bull Run. Let's learn more about this important Civil War battle.