"It, too, is much like iodine, but heavier. It is a black solid melting at 570 degrees; it is a metallic looking element, will conduct electricity somewhat, oxidizes in air to form an acidic oxide, and forms strong oxygen acids. It is far less active than iodine, except toward oxygen. It is very slightly soluble in water. It does not react readily with hydrogen, and the acid where formed is not as strong as HI." "I have seen so many new things here, I wonder if it may not be the element that precedes niton. Is it heavier than that?" "No," replied Tonlos; "it is just lighter than that element you call niton. I think you have none of it." "Then," said Arcot, "it must be the next member of the halogen series, Morey. I'll bet they have a number of those heavier elements." The gas was loaded aboard the _Solarite_ that evening, and when Wade saw the quantity that they had said was "rather disappointingly small" he laughed heartily. "Small! They don't know what that gas will do! There's enough stuff there to gas this whole city. Why, with that, we can bring down any ship! But tell them to go on making it, for we can use it on the other ships." Again that night they spoke with Earth, and Morey, Senior, told them that work was already under way on a hundred small ships. They were using all their own ships already, while the Government got ready to act on the idea of danger. It had been difficult to convince them that someone on Venus was getting ready to send a force to Earth to destroy them; but the weight of their scientific reputation had turned the trick. The ships now under construction would be ready in three weeks. They would be unable to go into space, but they would be very fast, and capable of carrying large tanks of the gas-producing chemicals. It was near midnight, Venerian time, when they turned in. The following day they planned to start for the Kaxorian construction camp. They had learned from Tonlos that there were but five of the giant planes completed now, but there were fifteen more under construction, to make up the fleet of twenty that was to attack Earth. These fifteen others would be ready in a week--or less. When they were ready, the _Solarite_ would stand small chance. They must capture one of the giants and learn its secrets, and then, if possible, with the weapons and knowledge of two worlds, defeat them. A large order! Their opportunity came sooner than they had hoped for--or wanted. It was about three o'clock in the morning when the telephone warning hummed loudly through the ship. Arcot answered.