The battle at Acre was the first in which war steamers took part, four paddle-wheel boats, the _Gorgon_, _Vesuvius_, _Stromboli_ and _Phœnix_, being included in the British force. They were not of a size to do much fighting, the bulk of which devolved upon the big sailing warships, the duty of the steamers being rather to wait upon the three-deckers in the capacity of armed tugs. The engagement had little, if any, influence upon the admiralties of Europe in deciding them as to the position steam navigation should take in the fighting marine. These steamers were not the first to fire a shot in war. That honour, if honour it be, is attributed to the Canadian-built _Royal William_, which crossed the Atlantic partly under sail and partly under steam in 1833, and it is on this performance that the Canadians claim to have sent the first steamer eastward across the Atlantic. While she was lying at London she attracted the attention of the Spanish authorities by reason of her speed, and after satisfying themselves that they could depend upon her to steam in a calm and even against the wind, they purchased her, with the consent of the Portuguese, to whom she was chartered, renamed her the _Ysabel Segunda_, gave her six guns, and used her against the Carlist revolutionaries. She was wrecked not long afterwards. In order to test the advantages of the paddle-engine in a fighting ship, the wooden 46-gun frigate _Penelope_, which was built for a sailer, was cut in two in 1843, and lengthened to enable her to accommodate the engines and 600 tons of coal. She and about thirty or forty sister ships had been constructed on the model of the French _Hebe_ class of frigates, but as they were now hopelessly outclassed by the heavier frigates introduced by other nations, this experiment was about the best use to which she could have been put. The sudden transformation of this out of date and none too powerful frigate into a vessel capable of holding her own against any vessel afloat created a tremendous sensation both in British and Continental nautical circles, and paddle-driven frigates of various sorts and sizes were introduced in the course of a few years in most of the European navies. When lengthened she was faster under sail than before, and her steam power made her independent of the wind and would have enabled her to choose her own position had she been called upon to participate in a naval engagement. Her new armament consisted of two large 10-inch pivot guns of 84 cwt. each, eight 68-pounders able to fire both shot and shell, and fourteen 32-pounders, “making a total of twenty-four guns of this immense calibre.”[32] Her steam engines, of 625 h.p. nominal and 700 indicated, were described as of greater power than any previously placed afloat in the navy or the mercantile marine. The cylinders were of 92 inches with a length of stroke of nearly 7 feet; the engines were of the direct acting type, such as were supplied to many other