1

 Newton Did Not Give Graviation As We Understand Now

Newton did never define the Law of Gravitation and equation F = GmM/r2 as we understand it now. In Book III of the Principia Newton gave Propositions I-IX (which correspond to the law of gravitation). These imply
    F    1/r2,    F    1/r ,      F   m   
Newton never wrote  F   . How product mM appeared in equation?
   Thus according to Newton      F    m/r2 , F    m/r    
                                                                ——-
  C V Boys  in 1894, in a lecture at Royal Society, published in the prestigious journal Nature
 has given a modern definition and equation of the Law of Gravitation
                              F = GmM/d2 
Reference: Boys, C V (1894) On the Newtonian Constant of Gravitation, Nature. 50 (1292):330

Scientifically C V Boys equation is not justified. Cavendish in experiments 1798 has calculated the density of the earth, not directly G .

2

Water Barometer, may be used in the measurement of g.

NASA’s Parker Solar Probe is about 173 million km from the Earth and controlled by scientists from the Earth. So experimental precision is exceptionally high.
    But so far scientists have not formed a Water Barometer. The height of the water column in the Water Barometer would be 10.33m (a tall barometer of about 40 feet), as the same for the mercury column is 0.76m. The height of the liquid column will be 8.2m.
                                                      Method for measurement of g 
     P = DLgH =Density of Liquid x acceleration due to gravity x Height of Liquid column                            (1)              
   So, a water barometer may be formed which has not been formed yet by scientists on a quantitative level.  Also,  
                      g = P /DL H                                                                                                                                                   (2)
P = 1.0136×105 Nm-2, DL density of liquid is measured. Then H is measured for water experimentally, so it gives an alternate method for the measurement of g. This is important for basic experiments relating to gravitation.