The smoke signal is one of the oldest forms of long-distance communication. It is a form of visual communication used over a long distance. In general smoke signals are used to transmit news, signal danger, or to gather people to a common area. History and usage In ancient China, soldiers along the Great Wall sent smoke signals on its beacon towers to warn one another of enemy invasion. The colour of the smoke communicated the size of the invading party. By placing the beacon towers at regular intervals, and situating a soldier in each tower, messages could be transmitted over the entire 7,300 kilometres of the Wall. Smoke signals also warned the inner castles of the invasion, allowing them to coordinate a defense and garrison supporting troops.In ancient Sri Lanka, soldiers stationed on the mountain peaks would alert each other of impending enemy attack (from English people, Dutch people or Portuguese people) by signaling from peak to peak. In this way, they were able to transmit a message to the King in just a few hours.Misuse of the smoke signal is known to have contributed to the fall of the Western...

A power outage caused plumes of smoke to flood downtown Baton Rouge streets Sunday morning and reports from a pastor who heard a small boom.

Several closures have been announced due to smoke and wildfires around the state.

National Weather Service says strong wind could bring wildfire smoke into the valley Tuesday.

Bakersfield and other communities on the east side of the San Joaquin Valley should get a break from the unhealthy wildfire smoke that has blanketed the region for days on

An atmospheric model produced by the National Oceanic and Atmospheric Administration is predicting daily wildfire smoke flow in the Bay Area.

People from San Francisco to Seattle woke Wednesday to hazy clouds of smoke lingering in the air, darkening the sky to an eerie orange glow that kept street lights illuminated into midday.

Hazy clouds of smoke from dozens of wildfires darkened the sky to an eerie orange glow over much of the West Coast on Wednesday, keeping street lights illuminated during the day and putting residents on edge.

The smoke out is “unprecedented,” according to the weather service, so heavy that satellite image views posted on the agency’s Twitter account could not pick up fog or the marine …

Air quality across Oregon is declining as strong east winds funnel in smoke from multiple wildfires burning across the Pacific Northwest.

Dr. Jesse Bracamonte, a Mayo Clinic family medicine physician, discusses the health concerns surrounding wildfire smoke.