Dark "disc" over Newton Creek in Camden, first appeared "round" and then to "oval" to a fine line to nothing!

This sighting happened when I was 15 or 16 years old which would make the year 1967 or 1968 and it was in the later part of the summer. I was behind my house in the Fairview Manor housing development(along Lake Shore Drive) and upon looking over the area of Newton Creek, I saw a perfectly round object that appeared to be a few hundred feet above the ground. It was dark-colored, maybe dark brown. It seemed to be about a quater of a mile away. It seemed to be about 150 feet in diameter. It moved very slowly from my right to my left and seemed to be shaped like a "globe"; after a few minutes, it's left to right momentum stopped and the object turned from being "round", and started to look "oval" until it finally turned into a thin line that disappeared from my sight!I remember the urge to want to run and try to find a camera, but being totally taken aback by what I was looking at, even when it appeared as "just a round object". It made no sound and was very well defined against the sky behind it. I realized as it disappered that I was looking at a "disc" the whole time!
Witness indicates that the date of the incident is approximate.  PD