IONOSPHERE

The sea was now his homeland. Here he could relinquish his titles, his fame, his responsibilities at last as search the world of wonders. The starry night skies drew his gaze, and his heart gradually healed. Enthralled once again with the experimenter’s love, he slowly and methodically equipped the central large gallery room of the Elettra with electrical apparatus. Marconi began thinking and researching once again. Soon, he was drawn into a study of the natural electric environment. Exploring the natural phenomena which produced static and noise provided a fascinating study tapestry against his wanderings imder the night sky. Process which continued to plague his large VLE stations, the facts which he once strove to secretize, now became a most wonderful new study. It was a liberating experience to study and not be required to report and finalize. Out at sea, there were only secrets, the wonderful secrets of Nature.

Mctfconi discovered the frailty of wave propagation across the seas. This was a fact reported by Tesla a decade before. He began investigating the electrical layers which he believed were found in some atmospheric layer above the clouds. Mahlon Loomis had suggested this very thing as early as 1864. Marconi reconstructed an apparatus which he had built when yet a boy. It became part of his original demonstration when he transmitted shorter wave signals across Salisbury Plain for the British Military. This shortwave beam signalling device was nothing more than the very oilbath spark generator of Dr. Augusto Righi. Marconi placed the spark gap itself in the bent copper parabolic mirror after the manner of Heinrich Hertz. He then constructed a receiver, similar in construction but differing in function. A variety of sensitive materials and components were used to receive signals. Selenium (Tesla), spi-raJ loops (Tesla), single turn loops (Tesla), nickel powders (Branly), carbon powders (Tommassina), neon bulbs (Vreeland), and several other variations of these. Marconi began performing a series of very interesting transmissions which involved land based receivers and sea-based transmitters. But he did not engage line-of-sight transmissions as he used to do. Now, he aimed the parabohc mirrors toward the sky.

The experiment was performed in hopes that a moderately powered transmitter could reach a distant site by reflection alone. The land based receiver remained fixed, an assistant listening for signals. Marconi took the Elettra straight out to sea, taking a straight route away from the reception site. Aiming the transmitter at the sky, Marconi began tapping out signals. The cissistant was to record the time when signals were maximum or minimum. Engaging this procedure several times, Marconi recognized that reflections were indeed taking place. Signals grew to a maximum when he was at a distance from the reception site which formed a nearly perfect forty-five degree angle.

There were diversions from this rule, diversions determined by significant variations in ionospheric height. But these could be virtually predicted by the time of day, another fascinating fact. Publishing these facts, Marconi found that others were drawTi to the subject with avid interest. Dr. Fessenden, Kennelly, Austin, Appleton, and many other experimenters investigated the mysterious radio-reflective ionosphere.

The apparatus was relatively easy to make and portable. Tripods were seen in many locations, experimenters aiming their devices toward the sky. The remarkably consistent data, recorded throughout the period following World War I, told a tale of marvel. Here was a means by which shorter wave signals, requiring simple and not very powerful apparatus, could effect communications across great distances. The idea dawned upon Marconi with a flash. Use the sky instead of the ground! Now his path was suddenly clear.

Aimed toward the sky, highly directional shortwave beacons bounced fi-om the ionospheric layers as relatively strong echoes. Thus reflected fi'om the “ionospheric ceiling”, signals could be exchanged by anyone from anywhere. The surface of the earth might as well have been the floor of an immense basilica, where the faintest whispers projected from one spot on the floor could be heard in another. Reflection provided another wonderful feature for Marconi. He could use higher frequencies than ever before possible. This meant that his systems could be minuscule, inexpensive, and accessible to others. Popular short-wave radio!