Where a broker's contract for services required a sale of nineteen quarter-sections of land within thirty days, at $9 per acre, the broker to receive one dollar per acre commission, an instruction, in an action for commissions on the contract, that if the jury found that plaintiff procured a purchaser for all the land within the time, who was able, ready and willing to purchase, then plaintiff was entitled to recover the amount claimed, though only sixteen quarter-sections were sold to the procured purchaser, and by the owner himself, for a less sum than the price fixed in the contract, was not cured by a proviso requiring the jury to find that at the time the sale was finally consummated there still existed a contract between plaintiff and defendant to pay one dollar per acre commissions. Ball v. Dolan, 18 S. D. 558, 101 N. W. 719.