Robert H. Jackson, Sartor v. Arkansas Natural Gas Corporation…
“ In considering the testimony of expert witnesses as to the value of gas leases, this Court through Mr. Justice Cardozo has said: 'If they have any probative effect, it is that of expressions of opinion by men familiar with the gas business and its opportunities for profit. But plainly opinions thus offered, even if entitled to some weight, have no such conclusive force that there is error of law in refusing to follow them. This is true of opinion evidence generally, whether addressed to a jury * * * or to a judge * * * or to a statutory board.' Dayton Power & Light Co. ”
