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.
The first recorded use of rockets in the Civil War came on July 3, 1862, when Maj. Gen. J.E.B. Stuart's Confederate cavalry fired rockets at Maj. Gen. George B. McClellan's Union troops at Harrison's Landing, Va. No record exists of the Northerners' opinion of this premature Fourth of July fireworks demonstration.