Billed as the ideal bench for a theatre organist, the so-called Howard "Wonder" Seat (photo) was invented in the heyday of the silent cinema to provide an unobstructed view of the organist's feet and a more comfortable and flexible alternative to the traditional stationary organ bench, as theatre organists would spend hours sitting at the console accompanying silent films.
A 2-manual Wurlitzer model 160C theatre pipe organ of 6 ranks was installed in the Temple Theatre in Hammond, Indiana, in 1921; this model was unusual in that its bottom manual was 88 keys with a split point at middle f#, which allowed it to function as a 3 manual; the console at this venue was also installed in an unusual way, on a very small movable cart that made it possible to move it from the balcony to the ballroom but impossible for anyone over 5-foot-5 to play it; it's first organist was E.H. Howard, who, as a result of playing that instrument, is credited with inventing the seat that bears his name.
Because theatre pipe organs were typically installed in the orchestra pits on very narrow turntables and lifts, the Howard Seat was widely supplied for these instruments all over the world, where space for a bench was compromised.
This seat was a sort of double bicycle-saddle arrangement with 2 heavily padded, felted cushions for the buttocks supported on minimal steel tubing fastened to a wide, flat steel pedestal which slid part-way under the pedalboard, thus occupying almost no additional floor space; the top of the seat, which was adjustable in height, was set on a turntable that swiveled to accommodate the turning of the body and was offset forward "to diminish the problem of leaning forward and the feeling of falling off the bench." The cushions were typically notched at the back to remove any pressure from the tailbone (coccyx).
In reality this "problem" of feeling like you're falling forward off the bench is a non-issue.
When you're sitting correctly on a traditional bench, you're clear up on the edge of it, and it feels a little like you're going to fall off; this feeling is counterbalanced by the spring tension in the keys pushing back like a trampoline; the result is equilibrium, with the fulcrum being right around the waistline.
If your habit was to sit a little further back on the bench, the legs wouldn't have been as free to move, you'd have to lean more forward from the waist, tension would have developed in the shoulders, neck, and back when you had both hands on the top manual, fatigue would set in, and the Howard Seat would have seemed like a Godsend [See blog, What About Bench Position].
Theatre organists who used this seat had to first learn to "ride" it so they became accustomed to its action, but some performers used it exclusively; it's claimed that the famous theatre organist Jesse Crawford demanded a Howard Seat all all his performances because of the freedom it gave him; he evidently felt at a disadvantage without one.
Other organists saw it as a frightful invention.
The concept behind it was to save floor space needed for a traditional bench, give the audience an unobstructed view of the organist's feet, and hopefully provide more freedom to the performer and make it more comfortable to play for extended periods.
What it did give an organist, unquestionably, depending upon whether or not it was positioned and adjusted properly for their size, was a sense of insecurity and backache.
Organists come in all different sizes, and they're all wired differently; a bench or seat that's works and is positioned properly for somebody 5-foot-2 may not work at all for somebody 6 feet tall.
In the end however, what kind of bench or seat we've got to work with is less important than its height, how far away it is, and how we're sitting on it.