Armstrong Aggregates Co. wrote a letter to Bishop on May 2nd offering to sell him 200 tonnes of scrap mica at $180 per tonne. Bishop received the letter on May 3rd. A few weeks later, Bishop checked the price of mica, and discovered that the market price had risen to $185 per tonne. On May 22nd, Bishop wrote Armstrong Aggregates Co., accepting the offer. Armstrong did not receive Bishop's letter until May 30th. Armstrong refused to sell the mica to Bishop at $180 per tonne, but expressed a willingness to sell at the current market price of $187 per tonne.

Bishop instituted legal proceedings against Armstrong for breach of the contract that he alleged existed between them.

Discuss the rights (if any) and the liabilities (if any) of the parties, and render a decision.