36 ;.': Dr. Tyudall on the Progress of the Physical Sciences 



8. German silver, 4b. Brass, 

 5 raillims. thick. 6'3 niillims. thick. 



9. Tin, 

 6'3 milHms. thick. 



10. Lead, 11. Rose's fusible metal, 12. Bismuth, 

 6*2 millims. thick. 6 millims. thick. 6 millims. thick. 



II. Experiments tvith cylinder exhausted. 



1. Silver, 

 5 millims. thick. 



2. Copper, 

 5 millims. thick. 



3. Gold, 

 5 millims. thick. 



4. Brass, 

 5 millims. thick. 



5. Iron, 

 5 millims. thick. 



6. Steel, 

 5 millims. thick. 



