thanks again all, lots of good info

I checked the inside of the tire and there is one place where something came through the tire all the way (a piece of glass), but this particular tire has flatted 7 times (I think) within the past year

4 times it sounded identical to yesterday when the tube tore near the valve stem

all fixed by the same shop. I told my son to ask the guy what he was finding in the tire, and the last two times all he came back with was "he said you ran over something"

I order Velox 22 mm rim tape, and 2 tubes size 26 x 1.50-1.75

hope this is the right size, and thanks again