<HTML>Andrew, I have an 1890's Chickering and Sons 79B upright with the Schwander butt and brass rail with the same secondary jack spring.  The first piano I owned with this spring was a turn-of-the-century Bechstein upright.  This was a very responsive action, although I suspect it wasn't because of the extra spring.   Dolge's book has drawings which have the spring on Schwander and Langer actions of the 19th century.   Mason and Hamlin had their own take on the idea using a leaf spring;  I had a "Screwstringer" with this. Greater minds than mine have expressed skepticism over this spring.  If the idea is to return the jack quickly the coil-type jack spring also found on these actions     does a sufficient job.  Getting the jack back under the hammer butt is one thing;  maintaining some kind of perpetual engagement of the two parts, which the grand repetition comes closest to doing, is not accomplished by this design.  The Fandrich/Trivelas action does this, and I can't see how any of these auxiliary springs function to maintain engagement.  It is interesting, though, that most of these actions with auxiliary jack springs have the Schwander butt spring, a weaker spring which results in a less rapid return of the hammer to rest.  This could keep the hammer/butt assembly engaged with the jack, which may be one reason why these actions seem responsive.  But the extra spring doesn't seem to me to do anything different than the coil spring.  If so, it was sure a lot of trouble for nothing.  Any other thoughts on this spring? Bill Shull, RPT In a message dated 6/18/02 4:39:33 PM Pacific Daylight Time, ANRPiano@AOL.COM writes: <BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">I had a customer bring by the action of the piano he is refinishing.  He wanted me to replace the bridal straps, dampers, etc.  This action includes one very unique feature which I, in my limited experience, (15 years) do not remember seeing before except on a certain west coast action.  There is a spring connecting the jack and hammer butt to speed the return of the jack under the butt.  The spring is about the length and shape of the hammer return spring and it is connected to the butt by means of a silk thread attached behind the jack felt on the butt.  There is also a slot in the jack for the silk to pass through in order to connect to the spring.  At the bass of the jack is a spring tensioner.  The piano is a Chickering Bros. (the Chicago branch of the family) apparently from the early part of the century. BTW from the best I could tell this system worked as I imagined it was intended to work.  The jack did reset before the hammer returned to a full rest. Has anyone seen one of these before?  I have seen a number of Chickering Bros. pianos and they all seem to be well built, often with "unique" features.  It seems the experimentation bug was genetic. Andrew Remillard </BLOCKQUOTE> </HTML>