sentences:  The designers had to design a small cruiser with armor protection that had an optimal combination of speed, armament, and stability, along with the endurance to operate on foreign stations in the German colonial empire.The resulting "Gazelle" design provided the basis for all of the light cruisers built by the German fleet to the last official designs prepared in 1914.After the first seven ships had been built or were under construction, the Construction Department improved the design slightly, strengthening the armor on the conning tower and increasing the beam, which allowed more space for coal storage, and thus a longer cruising radius.