International Filter Co. (International) (plaintiff) manufactured machinery for water purification. Conroe Gin, Ice & Light Co. (Conroe) (defendant) was a manufacturer of ice. International submitted a proposal offering to sell certain equipment to Conroe for $1,230 and providing that modification of the sales contract could be made only by a supplementary agreement signed by both parties. Conroe noted his acceptance by writing on the document and also wrote on the document that the shipment was to be made by March 10. Conroe then submitted the document to International, whose president endorsed the document with “O.K. /d/ /s/.” International then wrote Conroe a letter dated February 14 acknowledging the receipt of the document and confirming shipment on March 10. Subsequently Conroe attempted to countermand the order by two letters. International denied the right to countermand and sought specific performance of the alleged contract. International appealed from a bench verdict for Conroe.