| 摘要 |
<p>The plastics roof is particularly designed for erection over open air swimming using the rays of the sun to heat the water. It can be suspended at the apex by a rope from a frame, the rope being reeved round a pulley to a winch, while the roof itself is weighted at the bottom, it being possible to raise the roof to any desired height. Water can be circulated by pump between the bath and the roof apex, then flowing into a circular spray pipe below it.</p> |
