Sims contracted in writing to sell Blake one hundred electric motors at a price of $100 each, freight prepaid to Blake's warehouse. By the contract of sale, Sims expressly warranted that each motor would develop twenty-five brake horsepower. The contract provided that the motors would be delivered in lots of twenty-five per week beginning January 2 and that Blake should pay for each lot of twenty-five motors as delivered, but that Blake was to have right of inspection on delivery. Immediately on delivery of the first lot of twenty-five motors on January 2, Blake forwarded Sims a check for $2,500, but on testing each of the twenty-five motors, Blake determined that none of them would develop more than fifteen brake horsepower.

What is the Issue, Rule, Application and Conclusion?