Scientific American Supplement, No. 664, September 22,1888

The gunners of the French fleet are possessed of a skill which is recognized by all the maritime powers, and these picked men proved this at the siege of Paris, where they made themselves illustrious, not only by their courage and their coolness, but also by the accuracy of their firing.
Nothing is neglected, moreover, to keep up the precision of hand and eye that distinguishes them, and which has become so much the more necessary in that it is no longer a question of firing a broadside at the enemy and reckoning on one ball being more fortunate than another in damaging the enemy's ship. At present, the most powerful ironclad has four, and sometimes six or eight, guns of large caliber, which are of from 30 to 100 tons. Every shot represents not only an enormous sum, but also a prodigious force expended, and so powder must not be used too lavishly, since the shot should be in relation with the colossal power that it represents, and the shell adopted in the navy is accompanied with so disastrous effects that a single one, well directed, is capable of reducing the enemy's ship to impotence. So exercises in firing are becoming more and more frequent, and they have a right to be multiplied, inasmuch as the present guns are complicated affairs, the maneuvering of which requires constant practice.
Our engraving represents one of these exercises performed by the Squadron of the North, which is of recent organization, and which consists of the three ironclads Marengo, Suffren, and Ocean, and three coast guards Furieux, Fulminant, and Tonnerre. Each of the ironclads is provided with four 27 cm. guns and four 24 cm. ones, not counting the revolving guns, which constitute the small artillery reserved for fighting torpedo boats. The Furieux has two 34 cm. guns, and the Tonnerre and Fulminant each two 37 cm. ones.
An endeavor is made, as far as possible, to practice firing such as is done in a naval action, that is, at moving targets. To this effect, the dispatch boat Epervier tows a rectangular float about two meters in length, upon which are arranged two canvas balloons kept taut by a wooden framework. One of these balloons is white and the other is black. Each is a meter in diameter, and is supported by a rod which is usually a meter in height. The vessels of the squadron successively fire their large guns at this target, which moves at a definite velocity. The shell, on dropping into the water, raises an immense jet, which entirely hides the balloons when the projectile falls in a line with and sufficiently near the target.