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 upon delivery. Immediately upon delivery of the first lot of twenty-five motors on January 2, Blake forwarded Sims a check for $2,500, but upon testing each of the twenty-five motors Blake determined that none would develop more than fifteen-brake horsepower.

What is the Issue, Rule, Application, and Conclusion?