Note dd — BOOK IV.
Reading edition
As to the Velocity of Sounds, by Reason the most celebrated Authors differ about it, I made divers nice Experiments my self, with good Instruments; by which I found, 1. That there is some, although a small Difference in the Velocity of Sounds, with or against the Wind: which also is, 2. Augmented or diminished by the Strength or Weakness of the Wind. But that nothing else doth accelerate or retard it, not the Differences of Day or Night, Heat or Cold, Summer or Winter, Cloudy or Clear, Barometer high or low, &c. 3. That all kinds of Sounds have the same Motion, whether they be loud or languid, of Bells, Guns, great or small, or any other sonorous Body. 4. That they fly equal Spaces in equal Times. Fifthly and Lastly, That the Mean of their Flight is at the Rate of a Mile in 9¼ half Seconds, or 1142 Feet in one Second of Time. Vid. Phil. Trans. Ibid.