Indirect ways of assessing past temperatures, using so-called temperature proxies, take measurements of responses to past temperature change that are preserved in natural archives such as ice, rocks and fossils.
Wikipedia has an article on: Reorder tone. Wikipedia. fast busy signal â(plural fast busy signals) (telephony) An audible signal on a voice phone line that sounds more frequently than a standard busy singal, indicating that no transmission path to the called phone number is available.
Traffic Signals and Signal Coordination (Timing) General Information: Traffic Signals are a vital tool used to safely and efficiently manage vehicle, bicycle and pedestrian traffic on state highways. To achieve optimum efficiency, traffic signals must be monitored and adjusted to serve changing traffic patterns.