Note d — BOOK I.
Reading edition
It may not be ungrateful to the Curious, to take notice of the Velocity of these two Things.
According to the Observations of Mersennus, a Bullet-shot out of a great Gun, flies 92 Fathom in a Second of Time, (Vid. Mersen. Balist.) which is equal to 589½ Feet English, and according to the Computation of Mr. Huygens, it would be 25 years in passing from the Earth to the Sun. But according to my own Observations made with one of her Majesty’s Sakers, and a very accurate Pendulum-Chronometer, a Bullet, at its first Discharge, flies 510 Yards in five half Seconds, which is a Mile in a little above 17 half Seconds. And allowing the Sun’s Distance to be, as in the next Note, a Bullet would be 32½ Years in flying with its utmost Velocity to the Sun.
As to the Velocity of Sound, see Book 4. Chap. 3. Note 28. according to which rate there mentioned, a Sound would be near 17½ Years in flying as far as the distance is from the Earth to the Sun. Confer here the Experiments of the Acad. del Ciment. p. 140, &c.