Lynn Korwatch located on top of Telegraph Hill. George F. Sweeney and Theodore F. Baugh were the two individuals to present the idea of a wooden semaphore on top of Telegraph Hill. A semaphore is a system in which one uses two flags or poles and sends signals in an alphabetic code. Sweeney and Baugh expanded their system by placing a signal station on Point Lobos, which is located 20–30 miles from port in San Francisco. The reasoning behind this was that there was high demand from people wanting to know when the ships were arriving at an earlier time so that
International Code of Signals the Commercial Code. It came in two parts: the first containing universal and international signals, and the second British signals only. Eighteen separate signal flags (see chart) were used to make over 70,000 possible messages. Vowels were omitted from the set to avoid spelling out any word that might be objectionable in any language, and some little-used letters were also omitted. It was revised by the Board of Trade in 1887, and was modified at the International Conference of 1889 in Washington, D.C. The new international code of signals officially came into worldwide operation on 1 January 1901. At first