Also, the Japanese system presents the number 0 by moving flags in a circle, and those from 1 through 9 using a sort of the "rotary dial" system, but different from that used for European languages. As in telegraphy, the katakana syllabary is the one used to write down the messages as they are received. It is the right arm, holding the red flag, which moves as a pen would, but in mirror image so that the observer sees the pattern normally. For example, the character for "O", which is drawn first with a horizontal line from left to right, then a vertical one from top to bottom, and finally a slant between the two follows that form and order of the arm extensions. The display motions chosen are not like the "rotary dial" system used for the Latin alphabet letters and numbers rather, the displays represent the angles of the brush strokes used in writing in the katakana syllabary and in the order drawn. The flags are specified as a solid white rectangle for the left hand and a solid red one for the right. Because their writing system involves a syllabary of about twice the number of characters in the Latin alphabet, most characters take two displays of the flags to complete others need three and a few only one.
The Japanese merchant marine and armed services have adapted the flag semaphore system to the Japanese language. Although based on the optical telegraph, by the time flag semaphore was introduced the optical telegraph had been entirely replaced by the electrical telegraph some years previously. Many of the codepoints of flag semaphore match those of the Foy-Breguet electrical telegraph, also descended from the French optical telegraph. Field of Santa Clara University, "there is evidence" that Popham based his telegraph on the French coastal stations used for ship-to-shore communication. Flag semaphore provided an easy method of communicating ship-to-ship or ship-to-shore when the distances were not too great.
#Sailor doing semaphor signals images install#
Such a system was inconvenient to install on board a ship. The land system consisted of lines of fixed stations (substantial buildings) with two large, moveable arms pivoted on an upright member. At this point, sender and receiver change places.įlag semaphore originated in 1866 as a handheld version of the optical telegraph system of Home Riggs Popham used on land, and its later improvement by Charles Pasley. The receiver can reply with the "Attention" signal.
The sender ends the transmission with the "Ready to receive" signal. The receiver raises both flags vertical overhead and then drops them to the rest position, once only, to grant permission to send. The receiver uses a "Ready to receive" signal not shown above to grant permission to begin the transmission. The sender uses the "Attention" signal to request permission to begin a transmission. Letters can be signaled by first signaling "J". Numbers can be signaled by first signaling "Numerals".
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