LAST EDITED ON Dec-04-02 AT 02:45 AM (EST)

The second and first floor plans show the spiral stair to be set in an alcove with the second floor/first floor ceiling extending to the stair:
http://braveheart.users4.50megs.com/ramsey/crimescn1.htm
http://braveheart.users4.50megs.com/ramsey/crimescn2.htm

The ceiling of the hall terminates at the stair- I don't see that we need to project any vanishing lines to it.

Here is a great site with tables of dimensions for ordering a spiral stair:

http://www.stairwaysinc.com/design.htm

The minimum circumferance per National Code is 60". This would include a 4" pole with 28" steps/treads. Dave thinks the circumferance of the Ramsey stair is 72", or 34" treads-could be. The standard tread angle is 27 degrees. At a finished floor to finished floor height of 107-109", depending on whether they used 10" or 12" joist (possibly 10"as this was the add-on part of the house, maybe 12" to match older building) this would take 12-27 degree treads or 13 30 degree treads. This would make the depth of the tread in the middle about 8" to 9" and each rise from 8.25" to 9".

Therefore, Dave's estimate of 8.75" per rise seems very reasonable, which shouldn't surprise anyone should it?

And if you check out the floor plan links above go to the bottom of the page and see the photos of the stairs. I think a reasonable person looking at those pictures will admit it wouldn't be normal to bend down to reach below one's feet to pick up something on the next tread below, that is, unless you normally squat first and then reach down. Skipping a step and then turning around seems real reasonable to me. To do so only necessitates jumping down about 17" or 18" and clearing beyond a 9" tread. Anyone except Steve Thomas could probably do this.