649. 5-3/4" long, unidentified piece of hardware sent in by a visitor, patented Oct. 12, 1897:
650. 14" long
651. 19" long
The metal parts sticking out from the two hubs are connected where they cross.
After loosening the set screw, the hub on the left can be pulled to cause the pieces to retract.
652. Partial/close-up shot:
Click here to see more of this one.
653. 29" diameter, 6" wide
Last week's set is seen below, click here to view the full post: