Army mirrors that talked
During the last campaign against Geronimo in 1886, the U.S. Army introduced a heliograph system for the rapid transmission of messages across the Southwestern deserts. The heliograph was a small round mirror mounted on a movable bracket and a tripod. By catching the sun, it could flash coded signals great distances. The British had pioneered military use of heliographs in India during the 1860s. When Gen. Nelson A. Miles was chasing Montana Indians in 1878, he had six of the devices and found them very effective.
Upon his transfer to Arizona, he decided to use them there. Now by the time Geronimo and his handful of warriors made their final raid, the telegraph had been strung from Tucson to El Paso.
The trouble was the Apaches had learned to cut the wire and then false-splice it with rawhide, so that repair crews could not see the break from the ground. In this situation, the heliograph messages flashed from mountain top to mountain top were far more reliable. In a short time, Miles saw to the establishing of a series of signal stations from Robledo Peak about Fort Fillmore in the Mesilla Valley, westward to the main forts of Arizona.
Each site was manned by two or three operators with a half dozen guards and several couriers who could carry incoming messages to troops operating in the field. New Mexico had 13 permanent stations, and Arizona 14. From May to September in 1886, those in Arizona transmitted 2,264 messages, so the system was performing good service for the Army. Some of the sites, because of their isolated location, could communicate with only one other station.
But several, more favorably situated, were able to reach as many as five stations. The average distance between was between 25 and 30 miles. Gen. Miles claimed in his memoirs that most messages totaled about 50 words. But most contained as many as 200. Delivery of each word in code was slow and had to be repeated as a check on accuracy. At one point when the system was in full operation, Miles checked its efficiency with a test. He sent a 25-word message from the eastern end of the line in New Mexico to the last heliograph station on the far side of Arizona.
The reply came back for four hours, having traversed 800 miles. For the day, that was lightning speed. Scholars have long argued over just how important the heliograph was in bringing about Geronimo’s final surrender in September 1886. Gen. Miles was convinced that it played a key role, and he stated that on more than one occasion. He may also have started the story that when the wily Geronimo came to understand how the white men were communicating his movements by their talking mirrors, he realized that his cause was hopeless and sent orders to his scattered warriors to give up. Said one historian: “The heliograph was a decisive factor. Flashing all day from mountain summits, the mirrors kept the soldiers fully informed of Indian movements. The Apaches had not a moment’s rest.”
But other skeptical writers declare that the case in behalf of the heliograph has been badly overstated. Geronimo, they say, grasped the nature of the signals right away, for after all it was not unlike his own smoke signaling. He simply moved the range of his raiding out of the fixed path of the stations, and shifted his activity below the border to Sonora where they were no threat.
But from that it can be said that the heliograph line served as a protective barrier or screen, shielding the ranches and towns of southern New Mexico and Arizona from the last band of hostile Apaches.
History has accorded Gen. Nelson Miles considerable credit for establishing an elaborate and useful communications network on the Southwestern frontier. But evidence fails to support the popular claim that the heliograph played a central part in convincing Geronimo to end his raiding career. The story of the Army’s talking mirrors is a little one, tucked away in a far and forgotten corner of Southwestern history. But it remains a fascinating fragment of our past.