We therefore prepare the rooms under the oval rooms of the ground floor of the rotunda for furnaces, stoves etc.

【翻译】因此，在圆形建筑一楼的椭圆房间下面，我们安排了一些房间安装火炉、热炉等取暖。

【分析】主要结构：prepare the rooms... for furnaces, stoves，意为“安排房间为安装火炉取暖做准备”。其中,under the oval rooms of the ground floor of the rotunda 作定语修饰the rooms，意为“在圆形建筑一楼的椭圆房间下面”；the ground floor of the rotunda意为“圆形建筑的一楼”。