All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

298 All About Inventions for the transmission of electricity, telegraphic, and telephonic purposes. Nor have the possible uses for petroleum pro- ducts yet been exhausted. The chemists are toiling zealously and patiently in the laboratory, and are constantly indicating other and equally profitable fields of application. To-day, the science of applied chemistry in connection with petroleum has been advanced to such a stage as to induce one to wonder whether, in the near future, petroleum will not con- stitute an indispensable fundamental element in the preparation of artificial foodstuffs. But the enormous reliance which the world has come to place in oil is exercising one inevitable effect. It is becoming more and more difficult and expensive to win it from the earth. We have seen how Colonel Drake struck oil at a depth of 6 9 J- feet, and the cost of sinking his well could not have exceeded two or three hundred pounds, the expense in this instance having been inflated by the fact that he had to con- duct pioneering operations which necessarily involve excessive outlay. Even to-day it is possible to sink a well and to tap oil for a disbursement of a few pounds, but the yield will not be adequate to trans- form one into a millionaire, unless fickle Fortune is extraordinarily kind. Neither is the life of such a well likely to be very prolonged. The upper layers of oil, especially in the proved and worked fields, are being rapidly depleted, thereby compelling the sinker to drive his pipe deeper and deeper into the earth’s crust. This causes the price of drilling to rise very materially. In the United States wells are now being sunk to the i,ooo-foot