alarm signal system
121Clayton Tunnel rail crash — The tunnel s north entrance Date and time 25 August 1861 : 0845 Location Clayton, West Sussex Rail line Brighton Ma …
122History of timekeeping devices — For thousands of years, devices have been used to measure and keep track of time. The current sexagesimal system of time measurement dates to approximately 2000 BC, in Sumer. The Ancient Egyptians divided the day into two 12 hour periods, and… …
123international relations — a branch of political science dealing with the relations between nations. [1970 75] * * * Study of the relations of states with each other and with international organizations and certain subnational entities (e.g., bureaucracies and political… …
124ancient Greek civilization — ▪ historical region, Eurasia Introduction the period following Mycenaean civilization, which ended in about 1200 BC, to the death of Alexander the Great, in 323 BC. It was a period of political, philosophical, artistic, and scientific… …
125Animal communication — Animal communication, and indeed the understanding of the animal world in general, is a rapidly growing field, and even in the 21st century so far, many prior understandings related to diverse fields such as personal symbolic name use, animal… …
126Private security industry in South Africa — The private security industry in South Africa is a complex and vast entity that includes multiple disciplines. Many credit the rise of the Security Industry with the high crime and resultant paranoia after the first democratic elections in 1994.… …
127Pheromone — Fanning honeybee exposes Nasonov gland (white at tip of abdomen) releasing pheromone to entice swarm into an empty hive A pheromone (from Greek φ …
128TXE — TXE, which stands for Telephone eXchange Electronic, was the designation given to a family of telephone exchanges developed by the British General Post Office (GPO), now BT, designed to replace the ageing Strowger systems. When World War II ended …
