272 



M. Becquerel on the Development 



Substances pressed. \ 



Pressures. 



Velocities 



Crystallized Sulphate of Barytes 

 polished ; Cork. 



Values 

 of a. 



10 



10 



la 



15 



15 



6 



15 



20 







5 



10 



Values 

 of d. 



1 











60 



5-3 



2 



12 



13 



3 



14 



IS 



Electric 



intensities 



by the 



formula 



10 + rf 



^lO + a 



Calcu- 

 lated 

 electric 

 inten- 

 sities. 



105 

 2-1 



3-1 



42 

 6-3 



We again see, by the results exhibited in this table, that 

 the electric intensities increase in proportion to the pressures. 



Let 



