"You would meet with plenty of wonders if you would but keep your eyes open to see them," observed Cousin Silas, who overheard my observation. The reply, however, did not quite satisfy me; nothing like a gale or bad weather had occurred, and I began to suspect that we had already had a sample of the sort of life we were always to undergo at sea. "Hillo!" exclaimed Jerry soon after this, "what has come over the air, I wonder? Why, we have got into a regular red fog. What has caused it, Mr Brand; can you tell me?" "No, indeed, I cannot," answered Silas. "I've met with it more than once. It is a very curious phenomenon." "They do say it comes off from the coast of Africa," remarked Ben Yool, who was at the wheel, and from his age privileged to speak on such a matter. "It's full of red sand, and I've seen it covering the decks in some parts as if a man had been scraping a red holystone over them." We were still discussing the subject, when Captain Frankland came on deck. He listened for some time to what we were saying. "I am glad to hear you discuss the subject, my lads," he remarked in a kind voice. "Though you are wrong in your conjectures, if you will attend, I will try and explain what I know about the matter. It is a very important one, for by means of this dust--for dust it is--which fills the air, philosophers have been able to determine in part the difficult problem of the track of the winds in their circuits. How is this? you will say. Dust coming from one place surely cannot be distinguishable from dust coming from another. To the ignorant man it is not, but to the man of science it is. There are certain minute animal productions called infusoria and organisms peculiar to each portion of the globe. The expression is, the habitat of such infusoria is such or such a place. These infusoria can only be distinguished by a most powerful microscope. Professor Ehrenberg, who has devoted his attention to the subject, has examined specimens of the dust which is now falling on our decks. He found it composed of dry infusoria, the forms of which are found not on an African desert, but in the south-east trade-wind regions of South America." "South America, father!" exclaimed Jerry, pointing with his hand to the south-west. "How can those clouds of red dust come all the way out here in the teeth of the north-east trade-wind?"