Another important fact ascertained by the “Challenger" expedition was that the bed of the ocean is uneven, like the surface of the land; there are peaks and valleys under the ocean similar to those with which we are familiar. The enormous collections that were brought home by the expedition were subsequently studied and described by well-known specialists belonging to nearly every civilised nation. Some idea of the importance and value of the expedition may be gathered from the fact that the official records and descriptions fill fifty bulky volumes.
No sunlight whatever penetrates the deepest parts of the ocean. Probably all is dark below two hundred fathoms, i.e. twelve hundred feet, except the small degree of light emitted by the phosphorescent animals. Owing to the lack of sunlight, there is an almost entire absence of vegetable life in the deepest parts of the ocean. Sir John Murray, the eminent oceanographer, calculates that on more than nine-tenths of the ocean floor there are no forms of vegetation of any kind.
Our knowledge of the ocean and the ocean depths is still far from complete. So many difficulties exist that progress must necessarily be slow. These difficulties arise principally from the fact that, in the majority of cases, the observations are necessarily indirect. At the surface of the ocean direct observation is possible, but our knowledge of the conditions prevailing in deep water, and of all that is there taking place, is almost wholly dependent on the correct working of instruments, the action of which at the critical moment is hidden from sight. Dredgings and soundings, however, reveal many important details, and divers are able, from time to time, to add to our knowledge of marine life and conditions.
When the cinematograph first made its appearance no one dreamt of its enormous and far reaching possibilities as a scientific instrument. Essentially, at the outset, intended to provide a cheap form of amusement, it was not long before it was seen that the cinematograph could be used not merely for purposes of entertainment, but also for those of instruction. At the present time we are beginning to understand a little more about the future possibilities of the cinematograph in connection with science and education.
The remarkable and unique application of the cinematograph to obtaining details of submarine life, the story of which will be told in these pages, reflects the greatest credit on the perseverance and ability of the Williamson brothers, who succeeded in perfecting the apparatus for taking submarine motion pictures - truly a wonderful achievement. The illustrations reproduced in this book are taken from photographs filmed by the Williamson Submarine Expedition. They enable us to understand the apparatus employed, and bring before us the panorama of a marvellous submarine journey of thirty leagues along the floor of the ocean. We shall read about the famous Marine Gardens which form one of the great attractions of Nassau, in the Bahamas, and can picture in imagination the indescribable beauties of the deep. Nature's wonders, whether in plant life or in animal life, in their myriad forms are placed before us. Scenes connected with sponge fishing and coral fishing have been photographed; we witness a diving scene; and, probably the most wonderful of all, we get a pictorial representation of a desperate life-and-death struggle between a daring swimmer, armed only with a knife, and a huge, blue, man-eating shark, the terror of the Bahama waters. This is undoubtedly one of the most thrilling scenes ever beheld by human eyes. For the first time in the history of mankind some of the secrets of the ocean have been revealed, and the story of the methods by which this has been done forms the subject matter of this book.
Sir John Murray (1841-1914)
The cinematograph (or cinematographe)