It was most remarkable that no reply could come from Earth to the Bonians, yet the three visitors could hold communication at all times, and at the first thought it seemed to point to the superiority of Earth, but not so when it was remembered that the travellers were obliged to use special and elaborate ‘wave’ apparatus in delicate sympathy with those on Earth, whereas the Bonians and all other inhabitants of the solar system conversed by pure telepathy—transmission of thought—alone, without instruments. Dennis and his friends determined to put Bona in direct communication with Earth by making another ‘wave’ apparatus like their own for the natives, and after considerable time and trouble they succeeded and, proud of their achievement, sent the first message from actual Bonian soil. What was their astonishment, however, to find all their work useless, for although the messages were really sent, Earth did not receive any of them. They could ‘wave’ from the _Regina_, but not from the planet; and after several weeks of most assiduous experimenting, they were compelled to abandon the project and bow to the inevitable—Earth and Earth alone was the one outcast in the system over which old Sol ruled. Disappointing as was the failure, it added considerably to the already unique powers of the vessel, which, by some mysterious affinity in its control of gravity, was alone enabled to hold communication with the instruments on Earth, with which its own were in sympathy. “Can you tell us, positively, what was the cause of your planet’s coming into the Earth’s orbit?” asked Dennis, _àpropos_ of the subject of gravitation which was under discussion. “We do not know exactly,” was the reply; “according to the records we were at one time beyond the star you call Neptune. We were even then in the solar system as we are now, but had a double orbit, one round a subsidiary sun as one of the members of a small solar family, and the whole system of which we were a part revolved round our present sun, but far outside the orbit of Neptune, and altogether invisible to your Earth. The sun round which we revolved became cold, too cold to retain its system, and we were more closely drawn into that of the greater sun.” “We on Earth know very little indeed of the limitless space beyond Neptune,” said Ross; “our instruments reveal little to us beyond space after space, and stars and more space _ad infinitum_.”