Aztec, New Mexico, UFO incident concerning the memo. In addressing the memo's context and possible connection to a hoax, the Bureau wrote, "Finally, the Hottel memo does not prove the existence of UFOs; it is simply a second- or third-hand claim that we never investigated. Some people believe the memo repeats a hoax that was circulating at that time, but the Bureau’s files have no information to verify that theory." The incident gave birth to the Aztec UFO Symposium, which was run by the Aztec, New Mexico library as a fundraiser from 1997 until 2011. Aztec, New Mexico, UFO incident The Aztec, New Mexico, UFO
Evolution of timpani in the 18th and 19th centuries Evolution of timpani in the 18th and 19th centuries The modern timpani evolved in the 18th and 19th centuries from the simple 12th-century membranophone of the Naker to a complex instrument, consisting of a suspended kettle with a foot operated clutch, capable of rapid tuning. The technological evolution of the instrument led to increased interest in its capabilities and sound among such composers as Ludwig van Beethoven, Robert Schumann, and Hector Berlioz. Initially used only outdoors, the instrument underwent modifications in the 16th and 17th centuries that led to its incorporation into chamber ensembles. During the 18th and 19th centuries,