1926. This work teaches the study of salesmanship and business efficiency. It discusses the fundamentals of salesmanship and how the potential salesman must master the principles and learn to think from cause and effect. It teaches how to apply principles and that salesmanship is not a veneer or outside polish. Basically, there are four factors in salesmanship: the salesman, the customer, the goods, the mental process. Knox illustrates how the salesman must develop, know the goods he is selling, how to analyze customers and how to apprehend the mental process involved.