| Chapter 11: The
        Heliograph  One of my duties was to
        relay messages from Willis, a man stationed on Fish Butte. He was across
        the Locksaw River, 13 to 15 miles away as the crow flies, with a valley
        a mile deep between, bottomed by a raging river. He had no telephone; so
        we had to communicate by heliograph.
 A heliograph is a
        mirror about 4" square which reflects the sun's rays toward the
        station desired. There is no limit of distance, as long as both points
        are visible. Willis talked with Graves Peak 80 miles away. The set-up is as
        follows: 
 The silver is removed
        from the center of the mirror, about 1/8" dia. The mirror is
        pivoted vertically and horizontally, and a pointer which has vertical
        adjustment is located as shown. Looking through the unsilvered spot as a
        peep-sight and over the pointer to the station to be contacted, the
        assembly is clamped. In line with the direction desired, set up the
        shutter as close to the pointer as practicable. The mirror is then
        adjusted until the reflected light is directed on the white shutter.
        When the shadow of the unsilvered spot appears just over the pointer, we
        know that the ray is centered on our target. Frequent adjustment of the
        mirror is essential, and the alignment must not be disturbed.  As the Morse code has
        long and short dashes, a simplified code was adopted, in which all
        dashes are alike. The alphabet is divided into coordinates. The letter
        "Z" is omitted.
 The dashes correspond
        with the numbers in the margin, the vertical column being given first.
        Thus the word "ham" would be indicated as follows: 
          
            
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              --    - -    --- --- We used the code the
        first day and had no trouble to speak of. We also had an abbreviated
        code -- i.e. A-D-G might mean "bring grub," etc. We had
        numbers which I may find later, but have lost. |