'Overstrung' piano strings

Well - you may be like me and not really have known what that meant , until I was enlightened by the piano tuner today, who took the front off the lower half of my ancient upright, and showed me. My piano was made in 1892(!!!) in Germany and the angling of the strings extends the length of each string by about 18", which apparently enhances the tone and reverberation of the sound on each note -  so there !