until I have explained my mission.'
Tarzan nodded. 'In the jungle,' he said, 'we are not often pressed for time. Where do you intend making camp?'
'The guide that I obtained in the last village complained of being ill and turned back an hour ago, and as none of my own men is familiar with this country we do not know whether there is a suitable camp-site within one mile or ten.'
'There is one within half a mile,' replied Tarzan, 'and with good water.'
'Good,' said Gridley; and the safari resumed its way, the porters laughing and singing at the prospect of an early camp.
It was not until Jason and Tarzan were enjoying their coffee that evening that the ape-man reverted to the subject of the American's visit.
'And now,' he said, 'what has brought you all the way from Southern California to the heart of Africa ?'
Gridley smiled. 'Now that I am actually here,' he said, 'and face to face with you, I am suddenly confronted with the conviction that after you have heard my story it is going to be difficult to convince you that I am not crazy, and yet in my own mind I am so thoroughly convinced of the truth of what I am going to tell you that I have already invested a considerable amount of money and time to place my plan before you for the purpose of enlisting your personal and financial support, and I am ready and willing to invest still more money and all of my time. Unfortunately I cannot wholly finance the expedition that I have in mind from my personal resources, but that is not primarily my reason for coming to you. Doubtless I could have raised the necessary money elsewhere, but I believe that you are peculiarly fitted to lead such a venture as I have in mind.'
'Whatever the expedition may be that you are contemplating,' said Tarzan, 'the potential profits must be great indeed if you are willing to risk so much of your own money.'
'On the contrary,' replied Gridley, 'there will be no financial profit for anyone concerned in so far as I now know.'
'And you are an American?' asked Tarzan, smiling.
'We are not all money mad,' replied Gridley.
'Then what is the incentive? Explain the whole proposition to me.'
'Have you ever heard of the theory that the earth is a hollow sphere, containing a habitable world within its interior?'
'The theory that has been definitely refuted by scientific investigation,' replied the ape-man.
'But has it been refuted satisfactorily?' asked Gridley.
'To the satisfaction of the scientists,' replied Tarzan.
'And to my satisfaction, too,' replied the American, 'until I recently received a message direct from the inner world.'
'You surprise me,' said the ape-man.
'And I, too, was surprised, but the fact remains that I have been in radio communication with Abner Perry in the inner world of Pellucidar and I have brought a copy of that message with me and also an affidavit of its authenticity from a man with whose name you are familiar and who was with me when I received the message; in fact, he was listening in at the same time with me. Here they are.'
From a portfolio he took a letter which he handed to Tarzan and a bulky manuscript bound in board covers.
'I shall not take the time to read you all of the story of Tanar of Pellucidar,' said Gridley, 'because there is a great deal in it that is not essential to the exposition of my plan.'
'As you will,' said Tarzan. 'I am listening.'
For half an hour Jason Gridley read excerpts from the manuscript before him. 'This,' he said, when he had completed the reading, 'is what convinced me of the existence of Pellucidar, and it is the unfortunate situation of David Innes that impelled me to come to you with the proposal that we undertake an expedition whose first purpose shall be to rescue him from the dungeon of the Korsars.'
'And how do you think this may be done?' asked the ape-man. 'Are you convinced of the correctness of Innes' theory that there is an entrance to the inner world at each pole?'
'I am free to confess that I do not know what to believe,' replied the American. 'But after I received this message from Perry I commenced to investigate and I discovered that the theory of an inhabitable world at the center of the earth with openings leading into it at the north and south poles is no new one and that there is much evidence to support it. I found a very complete exposition of the theory in a book written about 1830 and in another work of more recent time. Therein I found what seemed to be a reasonable explanation of many well-known phenomena that have not been satisfactorily explained by any hypothesis endorsed by science.'
'What, for example?' asked Tarzan.
'Well, for example, warm winds and warm ocean currents coming from the north and encountered and reported by practically all arctic explorers; the presence of the limbs and branches of trees with green foliage upon them floating southward from the far north, far above the latitude where any such trees are found upon the outer crust; then there is the phenomenon of the northern lights, which in the light of David Innes' theory may easily be explained as rays of light from the central sun of the inner world, breaking occasionally through the fog and cloud banks above the polar opening. Again there is the pollen, which often thickly covers the snow and ice in portions of the polar regions. This pollen could not come from elsewhere than the inner world. And in addition to all this is the insistence of the far northern tribes of Eskimos that their forefathers came from a country to the north.'
'Did not Amundson ??and Ellsworth in the Norge expedition definitely disprove the theory of a north polar opening in the earth's crust, and have not airplane flights been made over a considerable portion of the hitherto unexplored regions near the pole?' demanded the ape-man.
'The answer to that is that the polar opening is so large that a ship, a dirigible or an airplane could dip down over the edge into it a short distance and return without ever being aware of the fact, but the most tenable theory is that in most instances explorers have merely followed around the outer rim of the orifice, which would largely explain the peculiar and mystifying action of compasses and other scientific instruments at points near the so-called north pole—matters which have greatly puzzled all arctic explorers.'
'You are convinced then that there is not only an inner world but that there is an entrance to it at the north pole?' asked Tarzan.
'I am convinced that there is an inner world, but I am not convinced of the existence of a polar opening,' replied Gridley. 'I can only say that I believe there is sufficient evidence to warrant the organization of an expedition such as I have suggested.'
'Assuming that a polar opening into an inner world exists, by just what means do you purpose accomplishing the discovery and exploration of it?'
'The most practical means of transportation that exists today for carrying out my plan would be a specially constructed rigid airship, built along the lines of the modern Zeppelin. Such a ship, using helium gas, would show a higher factor of safety than any other means of transportation at our disposal. I have given the matter considerable thought and I feel sure that if there is such a polar opening, the obstacles that would confront us in an attempt to enter the inner world would be far less than those encountered by the Norge in its famous trip across the pole to Alaska, for there is no question in my mind but that it made a wide detour in following the rim of the polar orifice and covered a far greater distance than we shall have to cover to reach a reasonably safe anchorage below the cold, polar sea that David Innes discovered north of the land of the Korsars before he was finally taken prisoner by them.
'The greatest risk that we would have to face would be a possible inability to return to the outer crust, owing to the depletion of our helium gas that might be made necessary by the maneuvering of the ship. But that is only the same chance of life or death that every explorer and scientific investigator must be willing to assume in the prosecution of his labors. If it were but possible to build a hull sufficiently light, and at the same time sufficiently strong, to withstand atmospheric pressure, we could dispense with both the dangerous hydrogen gas and the rare and expensive helium gas and have the assurance of the utmost safety and maximum of buoyancy in a ship supported entirely by vacuum tanks.'
'Perhaps even that is possible,' said Tarzan, who was now evincing increasing interest in Gridley's proposition.
The American shook his head. 'It may be possible some day,' he said, 'but not at present with any known
