In Adams Express Co. v. Ohio State Auditor, 166 U. S. 185, 221, 222, 17 S. Ct. 604, 606, 41 L. Ed. 965 (1897), Mr. Justice Brewer, delivering the opinion of the Supreme Court and discussing the evidence of the value of the property of the Express Company for the purposes of taxation, said: "According to the return filed by it with the auditor of the state of Ohio, as shown in the records of these cases, its number of shares was 120,000, the market value of each $140 to $150. Taking the smaller sum, gives the value of the company's property taken as an entirety as $16,800,000. The value which property bears in the market, the amount for which its stock can be bought and sold, is the real value. Business men do not pay cash for property in moonshine or dreamland. They buy and pay for that which is of value in its power to produce income, or for purposes of sale."