Abstract: This invention relates to a rolling shutter having a shutter curtain being wound around a winding drum forming n-polygonal winding layers. According to this invention, since a sudden change of a diameter of winding layer is eliminated, the damage and deterioration of the slats are precluded efficiency of winding and unwinding operation is improved, and it becomes easier to put a manual-operated rolling shutter of this type to practical use.The shutter curtain is comprised of slats being connected to each other and each winding layer is comprised of n slats which have the same vertical dimension. When the shutter curtain is being wound around the winding durm, the distance between the center of the winding drum and apexes of winding layers gradually increases by H/n. The distance H is the difference between a radius of a winding layer and that of adjacent winding layer(s).

Abstract: The hothouse for cultivation according to the present invention relates especially to a hothouse for cultivation enclosed with transparent members, wherein reflexion plates are provided on the northern side for reflecting the sunlight toward the soil surface inside the hothouse, and also to a hothouse enclosed with transparent members, wherein the hothouse comprises a shutter which can be opened and closed freely, and is switchable between two types of hothouses which are a hothouse composed only of the transparent members and a double hothouse comprising a heat insulation space between the shutter completely closed and the transparent members, so that the heat of the sunlight received by the hothouse for cultivation is most effectively used and kept in the hothouse.