The addition of the cupola, a lookout post atop the car, was introduced in 1863. Coal or wood was originally used to fire a cast-iron stove for heat and cooking, later giving way to a kerosene heater. Now rare, the old stoves can be identified by several essential features. They were without legs, bolted directly to the floor, and featured a lip on the top surface to keep pans and coffee pots from sliding off. They also had a double-latching door, to prevent accidental discharge of hot coals caused by the rocking motion of the caboose. Cabooses are non-revenue equipment and were often improvised or retained well beyond the normal lifetime of a freight car. Tradition on many lines held that the caboose should be painted a bright red, though on many lines it eventually became the practice to paint them in the same corporate colors as locomotives. The Kansas City Southern Railway was unique in that it bought cabooses with a stainless steel car body, and so was not obliged to paint them. Decline Until the 1980s, laws in the United States and Canada required all freight trains to have a caboose and a full crew, for safety. Technology eventually advanced to a point where the railroads, in an effort to save money by reducing crew members, stated that cabooses were unnecessary. New diesel locomotives had large cabs that could house entire crews. Distant dispatchers controlled switches, eliminating the need to manually throw switches after trains had passed. Improved signaling eliminated the need to protect the rear of a stopped train. Bearings were improved and lineside detectors were used to detect hot boxes, which themselves were becoming rarer with more and more freight cars gaining roller bearings. Better-designed cars avoided problems with the loads helped as well. The railroads also claimed a caboose was a dangerous place, as slack run-ins could hurl the crew from their places and even dislodge weighty equipment. Railroads proposed the end-of-train device (EOT or ETD), commonly called a FRED (flashing rear-end device), as an alternative. An ETD could be attached to the rear of the train to detect the train's air brake pressure and report any problems to the locomotive by telemetry. The ETD also detects movement of the train upon start-up and radios this information to the engineers so they know all of the slack is out of the couplings and additional power