Back in 2009, 2010 we still had these old telescope tubes inside the observatory.  You can see the old black tube up against the wall.  This was a 9 foot long tube that housed a 12.5 inch mirror which had a focal length of abut F7.5  It offered great views through an almost perfectly figured mirror.  The mirror was damaged over the years from bird dropping that fell on the mirror as the cover fell off the telescope while the observatory was closed.   Acid from insects and bird droppings likely etched the mirror.  It was far easier to replace the telescope and update it with a newer telescope, like the C14 you can see on the pier in the foreground.   On the shelf behing the C14 we can see a blue tube newtonian telescope tube, that was built back in 1977.  That had a 8 inch F5 mirror.  We built that telescope back in 1977 when I was president of the Lincoln Park Astronomy Club, a student club that used the observatory back in the 1970's.