Theory behind well tempered tonearm?

Thanks @sebrof 
I will read it over this weekend

I owned an original Well-Tempered Turntable many years ago and don’t really remember any shift of the arm fore and aft. The fluid in which the paddle (now, I guess a golfball?) was suspended was fairly viscous (thick) and acted as a damper as well as a substitute for more conventional bearings. The biggest issue was the amount of fluid used since that could change the sound. I had tricked out my table with a variety of mods, including a heavy brass clamp around the fluid cup, a more up-to-date motor, a different platter and perhaps some change to the arm wand (I don’t remember, it’s been quite a long time).
The table was a very good performer in the era of Linn at reasonable cost. It did not have the gravitas of more expensive, bigger tables I subsequently owned. I had a by then long in the tooth Technics SP-10 at the time I bought the Well-Tempered (in the mid-’80s?). Now the SP-10 has been restored and almost ready to use in my second system. The Well Tempered is long gone, but I had a positive ownership experience with it. I also used a range of different cartridges with it over the years it was in operation, all without issue.

@whart 
did you use a protractor to setup the cartridge? I am asking because my friend is having the Special Edition version (they only made 50 of them) and he told me he just mounted the cartridge onto the arm. No protractor needed since there is not any slot for adjustment for the overhang.
 Thanks 

@dangcaonguyen - don’t remember what tools came with the table, at that time, I was having help on turntable set up, particularly once I moved up in the cartridge world-- I had set up plenty of turntables in the early ’70s, but the Well-Tempered required someone familiar with it, and I got to the point where I was using fairly expensive cartridges (e.g. Lyra Parnassus was the last one on that table, I think), so can’t tell you more. Sorry. I was friendly with the fellow who was the US distributor for long while, but times change. Really haven’t kept up with the turntable or the company. At the time the arm and table were introduced, his work was considered ingenious, and it wasn’t crazy money.
Sorry I can’t provide more info. It’s been quite a while.

Thanks @whart 
I appreciate your response. Now I know for sure that the arm, cartridge still need to setup correctly to achieve the best performance. (Not just flush mounting like my friend suggested)