Tides from the Moon and Sun change the force of gravity. Pendulum clocks that use pendula are affected by this, but the resulting time errors are less than a millisecond over a day. These errors were measured by a few precision pendulum clocks between 1929 (the first data showing tidal gravity signals) and 1985. This paper shows the original results of each measurement and also compares these with simulations using modern tidal models.