P and D entered into an agreement for P to sell to D 350 tons of horse meat scraps at $50 per ton f.o.b. cars Portland. Minimum 50% protein, ground and sacked in 100 lb. net each. If the scraps analyzed less than 50% of protein, it is understood that Ds were to receive a discount of $5.00 per ton. A total of 349.25 tons were delivered, and of them, 29.25 tons contained 48.66 percent protein, and D paid, therefore, $45 per ton; 140 tons contained protein varying from 49.53 percent to 49.96 percent for which the defendant paid $45 per ton. P sued D to recover the deductions. P claimed that both P and D were engaged in the business of buying and selling horse meat scraps; that at the time said contract was entered into there was a custom and usage of trade in said business well known to both P and D as to the meaning of the terms 'minimum 50 percent protein' and 'less than 50 percent protein' used in the agreement. These terms meant that a protein content of not less than 49.5 percent was equal to and the same as a content of 50 percent protein. P claimed that this custom was well known to both P and D and that the contract was to have held to this meaning. D claims that the 140 tons with a protein content of 49.53 percent to 49.96 percent should have been regarded as within the 50 percent protein classification, and therefore P wanted the $5 per ton. D moved for judgment on the pleadings and it was granted. P appealed.