Where the appraisement of an invoice of imported goods made by the revenue officers at the custom house is not satisfactory to the importer, persons may be selected (under this name) to make a definitive valuation; they must be merchants engaged in trade. Auffmordt v. Hedden (C. C.) 30 Fed. 360; Oelberman v. Merritt (C. O.) 19 Fed. 40S.