Section 52, The Customs Regu- Citation

Where the supplier of any imported goods liable to Insurance.duty ad valorem does not insure the same against loss or damage there shall be added to the value of the goods for the purpose of calculating the duty such amount not being less than one-half of 1 per cent. of the. value for duty as the Comptroller may. in his discretion determine to be equivalent to the cost of insurance had such goods been fully insured.