Where the action of the court is founded upon evidence given by others, such evidence must be in writing, and be filed and preserved. [C51, §1604; R60, §2694; C73, §3497; C97, §4466; C24, 27, 31, 35, 39, § 12547; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §665.8 ]