A smoke signal is a form of visual communication used over a long distance, developed both in the Americas and in China. By covering a fire with a blanket and quickly removing it, a puff of smoke can be generated. With some training, the sizes, shapes, and timing of these puffs can be controlled. Puffs may be observed from long distance, apparent to anyone within its visual range. With this in mind, signaling stations were often created to maximise the viewable distance. Stone bowls used by Native Americans and the towers of the Great Wall of China are examples of signaling stations. Visual communication is the conveyance of ideas and information in forms that can be read or looked upon. ... World map showing the Americas CIA map of the Americas The Americas are the lands of the Western hemisphere or New World consisting of the continents of North America[1] and South America with their associated islands and regions. ... A bed covered by a blanket A painting by Henri de Toulouse-Lautrec of two people under a blanket A blanket is a type of bedding, generally a large, rectangular piece of cloth, intended to keep the user warm, especially while they sleep. ... Vapor (US English) or vapour (British English) is the gaseous state of matter. ... Smoke from a wildfire Smoke is a suspension in air (aerosol) of small particles resulting from incomplete combustion of a fuel. ... A Hupa man. ... A section of the Great Wall near Beijing during winter The course of the Great Wall is shown in this map dated from 1805 The Great Wall (Traditional Chinese: ; Simplified Chinese: ; pinyin: , literally long city wall) is a series of stone and earthen fortifications in China, built between 5th century...

There is no standardized code for smoke signals; the signals are often of a predetermined pattern discerned by sender and receiver. Because of this, smoke signals tend to only convey simple messages, and are a limited form of communication.