Small spinning circular shaped object passes between houses but doesn't come down.

My friend and I, ages approximately 9 and 10 years old, were playing catch with a baseball in his back yard on a bright sunny warm morning in June, approximately 1966, when what I perceived to be a boomarang came between his house and the neighbors house.  It was about 2 feet in diameter and between 15 and 20 feet off the ground traveling south when I saw it coming from behind my friend. I immediately yelled,"look a boomarang, lets catch it."  He looked up and saw it and we both waited for it to come down but it continued traveling on a straight steady course and did not come down as we expected it to. We ran and grabbed our sling shots and ran after it. 
We ran into a large open field behind his house and watched it as it traveled over a tree, which was in the yard of a house about 1 block away.  We knew that a large woods was immediaately behind that house and so we ran across the open field to the woods and then ran about 1 mile through the woods to find out if we could still see the object. 
We peered out over what was then a city trash dump but could no longer see the object.  It was traveling at about 10 miles per hour when it came between the houses and made no noise what so ever.  The object guided itself to pass immediately over the tree of the house which was one block away.  The object looked to me like a boomarang spinning so fast as to appear as a solid disc, but it may have actually been solid, I don't know. 
I chose to classify it as circular instead of disc because I don't believe it was very thick at all.  My friend still remembers this event today, which is at least 42 years later.  
This may have occured in either 1965, 1966 or 1967.
Witness elects to remain totally anonymous; provides no contact information.  PD