Cornish was a mail order house. One piano they offered was this type with special effects available on two of the four pedals. The left pedal is a conventional soft pedal which moves the hammers closer to the strings. The second pedal is a harpsichord sound. Then comes a guitar or banjo sound and finally the right pedal is a normal sustain pedal.
These effects are made possible by a special rail similar to the common dulciana or practice pedal. Along with a simple muting felt, Cornish added a felt strip for each key which had small wooden squares glued to each side of the end of the strip. The harpsichord effect is achieved by lowering the rail all the way down so that the wooden squares swing into the strings from the hammer movement. The guitar/banjo sound is achieved by lowering the rail a little less so that the hammer drives the wood directly into the string.
Many pianos had such effects. Player pianos often had a ukelele rail which used brass clips in a similar way to the Cornish system. Singer uprights had what seems to have been a small piece of sandpaper at the end of each strip of felt. Many piano players who desired that sound but had an unequipped piano have pushed thumbtacks into the striking portion of the hammer resulting in a sound like you hear in saloon pianos. Probably the best effects were achieved by the Wing & Sons pianos.