At the same time two other fast cruisers approaching the rate of the Congress were built (Volage and Active). Between 1870 and 1873 is seen the same search amongst dimensions to find the ones which will best satisfy the demands of speed, steaming capacity, and battery-power. The Shah, Raleigh, Boadicea, Bacchante, Euryalus, and Rover, ranging in displacement from 3500 to 6000 tons, overshooting the mark at first, and apparently best satisfied with dimensions falling between the Piscataqua and Congress types. All of these ships belong more properly to the Piscataqua than to the Wampanoag type; the latter appearing fully developed in the Iris and Mercury, in which, as in the Wampanoag, all is sacrificed to speed. The modifications in this case consist, first, in the steel construction, giving a strength of frame sufficient to withstand the engine-power; second, the reduction of dimensions, giving a displacement of 3700 tons; third, the increase in speed to 18 knots. In France is found, on the programme of 1873, provision for first-rate fast cruisers; accepting the necessity for this development of the general frigate type, this country deliberates and studies the birth of the type in 1865 in the United States, its development for six years in England, and finally crowns the English modifications with what to-day must be regarded as the most perfect development of the Piscataqua and Shah type. The Duquesne and Tourville have a displacement of 5400 tons, speed of 17 knots, and steaming capacity of 5000 miles at 10 knots. In these ships France borrows the English constructional development of iron sheathed with wood, while by an excellent arrangement she secures a full battery-power with an almost perfect command.