How have courts interpreted the meaning of a contract in view of the surrounding circumstances?

In Euless v. Westphal, 71 Cal.App. 611, 235 P. 742, it was said that any contract is to be interpreted in view of the surrounding circumstances with the aim to arrive at the intention of the parties, and cited cases are of little aid unless they arise out of similar circumstances. It is the function of the trial court to determine the meaning and effect of an alleged contract in suit in the light of all the cases and surrounding circumstances. In Sanchez v. Yorba, 8 Cal.App. 490, 97 P. 205, the court considered the surrounding transactions in construing a somewhat similar writing. In Wachs v. Wachs, 11 Cal.2d 322, 326, 79 P.2d 1085, 1087, the court said:

'The trial court should therefore have permitted appellant to plead and prove the surrounding circumstances, not for the purpose of varying the terms of the written instrument, but for the purpose of aiding the court in interpreting the contract of the parties as embodied in the written instrument.'

In Smith v. Blodget, 187 Cal. 235, 240, 201 P. 584, 586, the court said: