504 Experimental Researches on Gravitation. 



the surface. Therefore, on the one hand, the fact that the 

 matter would accumulate itself towards the centre would 

 have for consequence that the absorption of the gravitational 

 force of the greatest part of the matter would be accomplished 

 across greater thickness, as the gravitational action would 

 have to pass first chiefly from the deeper layers to the 

 surface, then to the exterior ; but, on the other hand, the 

 exterior mass has a reduced density, hence the absorption 

 itself is diminishing. Therefore these are two contrary 

 causes that in general will not balance each other, but the 

 effect of one is subtracted from the effect of the other, leaving 

 the mean true density not very different from the one 

 established by my experiment and calculation. 



Summary and Conclusion. — Examining Newton's Law, I 

 have come to think that the force of gravitation can weaken 

 itself by absorption due to ponderable matter. Following- 

 other arguments, I have come to suspect that the matter 

 which shows the force of gravitation might heat itself. 

 Although such conception might resolve in a new way the 

 old controversy on the origin of the sun's heat, I state it 

 with all reserve. 



I have undertaken afterwards to treat theoretically the 

 case of a spherical mass with constant density, subject to 

 the absorption of its own force of gravitation, and from this 

 work I have deduced the elements necessary ,to carry out an 

 experimental control of my hypothesis. I have carried out 

 this experiment by weighing in vacuo a leaden ball whose 

 weight was 1274 gr. symmetrically surrounded by 104 kg. 

 of mercury. Having previously avoided all the possible 

 causes of error, I have been able to conclude that the leaden 

 ball loses 7*7 . 10 ~ 10 of its weight by the presence of the mercury. 

 Such result causes the determination of the quenching constant 

 (factor of absorption) per unit of density and length, as 

 6'73. JO" 12 . 



Applying finally this result to the sun's case, I calculate 

 its true density as 4*27. 



The importance of this research is obvious, and I do not 

 think that reasons for criticism can easily be found. Anyway, 

 as I am the first to wish to test in all possible ways the 

 results I am publishing, 1 may mention that it is my intention 

 to repeat my experiments with far bigger apparatus. For 

 the purpose, in the Laboratorio di Fisica del Politecnico di 

 Torino (Italy), an apparatus is being built in such propor- 

 tions as will render possible an experiment with 10,000 kg. 

 of lead. On the results that I shall obtain with it I shall 

 report in due time. 



