The fossils of the mammoth reptiles and beasts which lived before the appearance of man on this planet are numerous in the fascinating West I know so well. In those arid desert hills are bones of the ancient rhinoceros--parent of our horse--and there are shells, and fossils of fish, and bones of animals imbedded in the strata of rock. Man reads these pages and he is lost in bewilderment, impoverished in thought, dumb for words, paralyzed by his inability to co-ordinate this evidence with any measure of time that will fall within the range of human comprehension. [Sidenote: Age of the Earth.] Historians say the world was 4,004 years old before the Christian era, and 1918 years have passed since then, making the age to date 5,922 years. It is not surprising that through the dark ages, dates and facts were lost. We have not a complete history in written language, but we have some very definite history in the rocks and hills and lands and seas. The world certainly is more than 5,922 years old. Read the record of time so plainly visible at Niagara Falls. Niagara Falls eats away about two feet of rock in a century; the gorge is a good many miles long. At the present rate of erosion, it takes 2,640 years to eat away a mile. Multiply that by the distance between the falls and Lake Ontario and you have an idea of how many years Niagara Falls has been at work. Before Niagara Falls was in existence, the country round about was under the sea; before that, under glaciers; before that, in the tropics, and I don't know how many times it has swung on its pendulum between Frigid, Temperate and Torrid Zones. We are certain to become lost in a labyrinth of mystery when we take these known facts concerning the earth's age, and try to specify any particular number of millions of years as the old world's age. 54. And now my pleasant occupation of writing this book draws to an end. I sincerely hope you have received some definite suggestions that will be helpful to you. To get you to think--that has been my aim. To get you to analyze yourself--to take stock of yourself--to know yourself--that has been the task I set before me. [Sidenote: How to Think.] Think vital thoughts of courage, faith and hope. Then will your days pass joyfully, and your path be one of peace, happiness and contentment. If you fill your mind with gloom and sorrow thoughts, your surroundings will reflect your mental attitude and will accentuate your misery and dejection. Do not give way to this weak, gloomy, pernicious thinking. You can be strong, you will be strong if you learn to control your thought habits. Can you face disagreeable facts without wavering? Can you meet adversity with courage in your heart and a smile on your lips? You can, if you have read this book carefully, calmly, thoughtfully, and put into practice the rules I have laid down.