The court properly charged that as there are different kinds of sales of lands, and if the contract does not specify the kind, it is for the jury to determine from the evidence and the letters forming the contract, and the attending circumstances, as to whether it included only auction sales, or both auction and private sales, for which plaintiff was to receive commissions. Cooli-gan v. Milwaukee & Sault Ste. M. Im. Co., 79 Wis. 471, 48 N. W. 717. Compare Sec. 972.