Counterclockwise rotations in the alleged northern hemisphere 4

Here I repeat the Foucault experiment. I enforce the small angle condition relative to the large oscillations in previous experiments. I use a stairwell at a parking lot to get about a 50ft rigid steel tether on a 45lb pendulum. This is the most precisely performed experiment so far in this series. The angle on the string at the bottom of the frame is 10 degrees so I observed a few degrees of clockwise rotation in about 20 minutes. This is consistent with my apparent location in the New England region of North America.