| 摘要 |
<p>PURPOSE:To minimize the possibility of foreign matter or the like dropped on a track without speed being restricted by air resistance, utilizing this railroad. CONSTITUTION:Inside a railroad which is provided with a rail 1 composed of a pump 3 and a shutter 4, surrounded by a cylinder 2 and is kept in a vacuum condition by the pump 3, a totally-enclosed train 5 equipped with an oxygen concentration controller is made to run.</p> |
