In order to struggle more effectively against the inhabitants of Dunkirk, we too began to build the vessel in question and their number increased rapidly under the urgent advice of our great Admiral Tromp. (~De Jonge~, Vol. I, pp. 388 and 389.) Later on they were built of larger size. [Sidenote: III 18] As has just been said the frigate was imported into France by the inhabitants of Dunkirk; thence it passed into England, in 1741, (~Holmes~, p. 121); all the same, this latter country had already had some of smaller size in 1646. The frigates played an important part in the Anglo-American war. Fire was one of the greatest enemies of wooden ships. Hence recourse was had to this element from the earliest times, in order to destroy an enemy’s fleet. It was not enough to throw burning pitch; more effective means were invented and the Ancients were already using fireboats to set fire to the hostile fleet. Time will not be wasted in conjectures about the fireships of the Ancients, which could only have been ordinary vessels. A summary description will rather be given of those used in the XVIIth century they being the only ones mentioned in Witsen’s well known work, pp. 166 and 167. Vessels of rather small size acted as fireboats, preferentially flutes or pinnaces. Later, “spiegelschepen” of 70 or 80 lasts were used. These vessels had a smooth continuous deck in which were made holes having an area of about 1.5 square feet. A trough starting from the poop ran forward for the entire length of the vessel, with side troughs leading athwartships, in a word, a train was formed which would let the fire run easily and quickly throughout the ship. For this purpose, the troughs were filled with a mixture composed half of gunpowder by volume, quarter of saltpetre and the remaining quarter made up of equal parts of resin and sulphur, the whole mixed with a little linseed oil. The troughs thus filled were covered with shavings which, in their turn, disappeared under faggots of light branches soaked in a mixture of resin, cod-liver oil, powder and saltpetre. In addition to this, the vessel was filled with other inflammable materials; the deck and the inside walls were smeared with grease and covered with a layer of finely powdered resin. Sometimes the fireships were loaded with open barrels filled with shavings soaked in tar. Special care was also taken that all ports and hatches should be left open so as to give plenty of draught. In order more surely to have the fireship catch the enemy’s vessel, strong grapnels were attached to the end of the bowsprit and to the ends of the yards; these grapnels could be detached by means of ropes laid along the ship. In order to deceive the enemy and to save appearances, quaker guns were stationed in the ports. Two iron guns only were placed aft for defence against attacks.