7. The toll to be levied under this Act shall become-due and payable immediately on the arrival of every Ship liable thereto within the harbour or roadstead of Singapore; and, immediately on the arrival of any such Ship within the said harbour or roadstead, the Collector appointed under this Act shall demand, or cause to be demanded, from the Master or other person in command of such Ship, payment of the toll of three cents of a dollar per ton for every ton of the registered harden or tonnage of such Ship, and if the same be not paid within two days after such demand made as aforesaid, or if, at any time after the arrival of such Ship as aforesaid, the said Collector shall have cause to suspect, or believe, that such Ship will immediately leave the said harbour or roadstead without paying such toll, it shall be lawful for any Justice of the Peace, upon an affidavit to that effect being made before him on oath by such Collector (which oath the said Justice is hereby authorized to administer), to issue his Warrant under his hand, directed to any Peace Officer of Singapore aforesaid, to enter on board such Ship and to seize and carry away any of the Goods, Merchandize, Guns, Tackle, Apparel or Furniture of or belonging to or on board such Ship, and to keep the same for the space of three days then nest, unless the said toll shall be in the mean time paid; and in case the amount of the toll due by such Ship shall not before the expiration of such three days have been paid, then the said Collector may cause the said Goods, Merchandize, Guns, Tackle, Apparel or Furniture so seized to be sold, and out of the proceeds of such sale shall pay the amount of the said toll to which such Ship shall be liable, together with the reasonable charges of the seizure, detention, and sale, rendering to the Master or Owner, or other person having the command of such Ship, the overplus (if any) on demand.