Here is a reprint from a very useful article regarding the state of Equal Temperament tuning from 1911 to 1917. While that may not seem very timely today, the information does show that many concepts that we know today such as the many possible checks, were known at that time but possibly not presented in a way that could be absorbed and put to use. Indeed, William Braide White's book was owned and presumably studied by many but for most technicians, only the familiar 4ths & 5ths sequence is what is remembered and not the myriad of checks and correcting procedures that would make it work.That being said, a chart of theoretical beat rates from Braide White's book is reproduced. It reveals two possible Equally Beating checks that may be employed for the utmost in accuracy: the "Inside 3rd, outside 6th" test (a M3 whose bottom note is a full step above the bottom note of an M6 will beat equally with it. Example: the G3-B3 M3 and F3-D4 M6). Also the "Lower m3 and upper M3" test: A M3 whose bottom note is a full step above the bottom note of a m3 will beat equally with it. Example: the F3-G#3 m3 and the A#3-D4 M3 will beat equally. When a temperament sequence is completed, it is useful to run both of these tests. Any two intervals which do not beat equally will reveal an error. Use other known tests to prove which note is in error and correct it.