Knot or not?

[struktor]

Compare:

1/
Ashley's Book of Knots (ABOK)  3234 Double Spanish burton.  
Power gained- five times.  

2/
A Double Spanish Burton fig. 102. Power gained- four times            
http://www.gutenberg.org/dirs/3/0/9/8/30983/30983-h/30983-h.htm#P54
or
http://www.gutenberg.org/files/30983/30983-h/30983-h.htm#P54

                                    Title: Knots, Bends, Splices     
                                           With tables of strengths of ropes, etc. and wire rigging
                                    Author: J. Netherclift Jutsum
                                    http://www.gutenberg.org/files/30983/30983-h/30983-h.htm

Compare:

1/  
Double Spanish Burton p.13. Power gained- five times:
http://mytreelessons.com/ks/mz/lines_of_force.swf            

2/
Ashley's Book of Knots (ABOK)  3235 Double Spanish burton.    
Power gained- five times.


Struktor

[TheTreeSpyder]

The Numbers look right to me; must understand legs of pull, and count how many pull on the load.

http://mytreelessons.com/ks/pulleys.png

This is assuming single pull, but can '2 hand' to place your body weight + your effort + the equal and opposite of your effort ( at a lessor input point of 2 less pulls as multiplier).  This can make a 3x system have a potential of 3x bodyweight + 4x Effort.  But, can make a standard 5x have a potential of 5x bodyweight + 8x Effort.

http://www.smackdock.co.uk/tackles.htm

http://www.mytreelessons.com/Marlinspike_%20Sailor.htm

http://www.mytreelessons.com/Marlinspike_%20Sailor_Rig.htm

http://www.mytreelessons.com/Flash/2handing.swf

[struktor]

http://mytreelessons.com/ks/pulleys.png
''i do think this line should go to center of pulley and end, not side''

I think so too.
Thank you

ABOK #3275
From Furttenbach (1629) :
http://digital.bibliothek.uni-halle.de/hd/content/pageview/117157