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Grugan Heliograph in 1881
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Heliograph Station #3 43-0513M White's Ranch signalling Bowie, May 1886
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Heliograph System, Dept. of Arizona, Lines and Stations
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1890 Heliograph Practice Map Table
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July 1886 AZ Heliograph Report
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August 1886 NM Heliograph Report
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July 1886 NM Heliograph Report
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1890 Heliograph Lines and Stations Map
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Diagram of US Army Signal Service Heliograph, Model of 1888
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United States Army Signal Corps Heliograph 1888, Duplex Mode
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Photograph of US Army Signal Service Heliograph, Model of 1888
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US Signal Service Heliograph, from Gallup, 1893, p. 30
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US Heliograph Screen of 1892 - The Kilbourne Two-Blade Screen
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Heliographing 70 miles in 1895
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US Signal Corps Heliographers, 1898
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Camp_Merritt_SIgnal_Corps_Camp_1898
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Camp_Merritt_Signal_Corp_Camp_1898_tonemapped
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Heliographing from Pehtud to Marahui 1898
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1899 Heliograph Pasay
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1899 Heliograph, Pasay, closeup
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US Heliograph Practice, Ft. Myer, May 18, 1900
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US SIgnal Service Heliograph, Peking, China 1902
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1913 Keuffel & Esser Heliograph Diagram.
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Features of Model 1905 US Signal Service Heliograph
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SIgnaling by Heliograph, Signal Corps, Fort Omaha, Neb. 1908
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US Signal Service Heliograph in 1908
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US Marines with Heliograph 1915
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US Signal Service Heliograph, Mexican Border, 1916
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USFS Forester Aiming a Heliograph - 1913
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USFS Forester Signaling with a Heliograph 1913
