http://203.117.31.137/MOESec/video/sci_s3NT.htmlLook up for Pneumatic and Hydraulic video and fast forward to the 9:50 mark. If you all interested in other machines and the way it works, this is for you.
Remember: Near the title, there is a view colum. Click on the type of view you want but select full video. The video is 12 minutes long including Credits. This is ETD old film.