And now, why had Barbicane & Co. chosen the Wamasai for the theatre of their operations? First, because the country suited them in regard to its geographical situation, as it was in a very little known part of Africa, and as it was very far from the territory usually visited by travellers. Then, the mass of Kilimanjaro offered them all the qualities of solidity and material necessary for their work. And, moreover, on the surface of this country were found the raw materials which they needed in a condition very easy to handle. A few months before leaving the United States President Barbicane had learnt from the Swedish explorer that at the foot of Kilimanjaro iron and coal were plentiful on the ground. No mines to dig into, no fields to explore a thousand feet deep in the earth's shell. Iron and coal were so plentiful even for this great undertaking that they only had to stoop down to pick it up. In other words, there existed in the neighborhood of this mountain enormous fields of nitrate of soda and of iron pyrites, which were necessary for the manufacture of melimelonite. President Barbicane and Capt. Nicholl had taken with them only ten people, of whom they were absolutely sure, and no one else. These ten men had to supervise the 10,000 Negroes put at their disposal by Bali-Bali, and to them was given the task of manufacturing the monster cannon and its not less monster projectile. Two weeks after the arrival of President Barbicane and his associate at Wamasai three large workshops were established at the southern foot of Kilimanjaro, one for the cannon foundry, the second for the manufacture of the projectile, and the third for the manufacture of the melimelonite. Now, first of all, how had Barbicane & Co. met the problem of manufacturing a cannon of such colossal dimensions? We will see and understand at the same time that the difficulty of creating such a device was not easily comprehensible by the inhabitants of the world. In reality the making of a cannon a million times larger than that of twenty-seven centimetres was a superhuman work. Already great difficulties had been met in the manufacture of pieces of forty-two centimetres diameter, which would throw projectiles of 780 kilos with 274 kilograms of powder. Barbicane & Co. did not think of these difficulties. It was not a cannon, not even a mortar, which they intended to make, but simply a gallery bored in the massive rock of Kilimanjaro,-a shaft of a mine, if you wish to call it so.