Also at night the _Denver’s_ boats were engaged in other and more exciting work. Owing to various causes there was a systematic smuggling going on between the two island republics. Small sailing vessels and motor launches were suspected of carrying contraband merchandise back and forth across the Bay at night, and organized bands of smugglers made the passage of the Massacre River from its mouth up to and beyond the San Domingan town of Dajabon, on its eastern bank, and the Haitian village of Ouanaminthe, directly opposite. The customs officers were doing their best, but they were too few in number to cope with the situation. In consequence money was being lost to both governments. The United States was administering the customs affairs of San Domingo, and the Navy had to be called in at times to aid in putting a stop to this illegal traffic. The presence of the _Denver_ had its salutary effect, and the smuggling by day in the boats had practically ceased, but at night activity was resumed. Consequently the ship’s boats, which during the day were engaged in the aforesaid work of surveying, became at night a fleet of armed patrols with certain definite sectors to cover. Many exciting chases resulted in the overhauling, arrest, and, occasionally, resistance and escape of the venturesome smugglers. The marines were often detailed for this night work in the patrol boats, and they enjoyed it, for there was always a chance of a lively little "scrap," and that is what marines enlist for--scrapping. All articles coming across the border were supposed to be entered at Dajabon, and after customs dues were adjusted the goods were sent to other points along the only really passable road which led through Copey, a town at the headwaters of the Estero Balsa, thence to Monte Cristi or towns and cities of La Vega Real. Somewhere in the dense jungle between Dajabon and the office of the Captain of the Port, where the two boys were now engaged in conversation, were trails unknown to the general public, and these trails the smugglers used for their purposes. As charts made by naval officers usually show but little of the interior terrain it was not the intention of Captain Bentley to include any roads on the map his officers were engaged in compiling. However, if Dick and Henry succeeded in getting information of value it was decided that their work should be incorporated with the rest. Both boys had studied surveying while at school, and early on the cruise they had secured a volume on Military Topography and spent many hours in acquiring a thorough knowledge of what was needed in a military map. First Sergeant Douglass, seeing how they desired to get ahead and only too glad to give them something to keep them out of mischief (for musics are generally conceded by all hands to be mischievous), allowed them to have a cavalry sketching case from his storeroom, and with this they became quite expert in making position-sketches and road-maps.