The Curious History of Relativity:

[Monte Davis]

PT:
> black holes...were postulated by John Michell in the 1780s

The very Michell who conceiv'd (tho' didn't Implement) Cavendish's
experiment, --- in a Context readily divin'd....

"The first man to measure the mass of the Earth was Astronomer Royal Nevile
Maskelyne in 1774, using a method called the Attraction of Mountains. He
worked out a mass of about five million million million tonnes. Using
Michell's apparatus, Cavendish calculated a figure close to six million
million million tonnes, which is close to what Newton had estimated a
hundred years earlier and close to the accepted figure of today."

http://www.exnet.com/1996/02/20/science/science.html