Black shere seen moving at high speed below the clouds in a straight trajectoryI was laying at the pool with my wife on a partly sunny day. At approximately 13:30, I was laying on my back with my feet pointing nearly due south. I had on a pair of high quality polarized sunglasses that allowed me to look up into the afternoon sky. I was watching cumulous clouds roll and build in the afternoon heat when a black object appeared in my field of view from high and right, moving down and to the left. This would be a Southeast trajectory. My immediate opinion was that the object was a large black bird, riding the wind at a very high altitude. A split second after the object entered my field of view, however, the “Bird” appeared to have its wings folded in. Birds who ride the thermoclines at that altitude very rarely flap their wings so I thought this odd. I waited for the “Bird” to open its wings. It never did.As I describe this at the luxury of taking the time to sit in my living room and record my memory of the event, please bear in mind, the entire event was over in approximately 5 seconds. When my eyes became fixed and focused on the object, I jumped up from my chair and moved to the right to prevent my view from being blocked by a tree that is next to the pool. What I was looking at was a solid black sphere. I got an extremely good look at the object and could judge altitude better as it passed under a large cloud. My view was never obstructed by the cloud. The object did not appear to have any lights on it, nothing flashing, and it made absolutely no sound. It left no form of contrail, but at that low of an altitude, neither would a commercial or private aircraft. No contrail, moved under a cloud so my estimation of altitude would be at or under 1000 ft.The direction of the object never changed. It continued out of sight on the same Southeastern trajectory it was on when I first saw it. I work in the aviation field and I am familiar with what a fixed wing and or a non-fixed wing aircraft looks like in the sky. I also know that any aircraft I am aware of, short of a non-powered glider can be heard from the ground at a below-cloud altitude. This object was absolutely silent. This object appeared to be a perfect sphere. There were no wings.I am not claiming the object I saw was of extra-terrestrial origin, but I know what I saw was no typical aircraft that I have ever seen before.