Other modern inventions in well-making machinery have consisted in innumerable devices to supplant manual labour and to meet new conditions. _Coal Oil_:--Reichenbach, the German chemist, discovered paraffine. Young, soon after, in 1850, patented paraffine oil made from coal. These discoveries, added to the long observed fact of coal oil floating on streams in Pennsylvania and elsewhere, led to the search for its natural source. The discovery of the reservoirs of petroleum in Pennsylvania in 1855-1860, and subsequently of gas, which nature had concealed for so long a time, gave a great impetus to inventions to obtain and control these riches. With earth-augurs, drills, and drill cleaning and clearing and “fishing” apparatus, and devices for creating a new flow of oil, and tubing, new forms of packing, etc., inventors created a new industry. Colonel E. Drake sank the first oil well in Pennsylvania in 1859. Since then, 125,000 oil wells have been drilled in that and neighbouring localities. The world has seldom seen such excitement, except in California on the discovery of gold, as attended the coal oil discovery. The first wells sunk gushed thousands of barrels a day. Farmers and other labouring men went to bed poor and woke up rich. Rocky wildernesses and barren fields suddenly became Eldorados. The burning rivers of oil were a reflection of the golden treasures which flowed into the hands and pockets of thousands as from a perpetual fountain touched by some great magician’s wand. Old methods of boring wells were too slow, and although the underlying principle was the same, the new methods and means invented enabled wells to be bored with one-tenth the labour, in one-tenth the time, and at one-tenth the cost. Many great cities and plains and deserts have been provided with these wells owing to the ease with which they can now be sunk. Another ingenious method of sinking wells was invented by Colonel N. W. Greene at Cortland, New York, in 1862. It became known as the “driven well,” and consisted of a pointed tube provided with holes above the pointed end, and an inclosed tube to prevent the passage of sand or gravel through the holes in the outer tube. When the pointed tube was driven until water was reached the inner tube was withdrawn and a pump mechanism inserted. This well, so simple, so cheap and effective, has been used in all countries by thousands of farmers on dry plains and by soldiers in many desert lands. With these and modern forms of artesian wells the deserts have literally been made to blossom as the rose. CHAPTER XXV. HOROLOGY AND INSTRUMENTS OF PRECISION. “Time measures all things, but I measure it.” So far as we at present know there were four forms of time-measuring instruments known to antiquity--the sun-dial, the clepsydra or water clock, the hour-glass, and the graduated candle.