Prof. Magnus on the Propagation of Heat in Gases. 91 



Transmission of Heat by a Glass surface (continued). 



Position of 



equilibrium 



of the 



needle. 



Observed 

 deflection. 



Position of 



equilibrium 



of the 



needle. 



Observed Difference, 

 deflection. 



Hydrogen under 18 millims. pressure. 



-0-5 

 -0-3 

 -0-1 



+0-2 

 +0-5 

 +0-5 



o 



o 



-0-4 



150 



-0-2 



150 



00 



15 2 



+0-3 



155 



+05 



157 



15-4 

 15-2 

 15-2 

 15-2 

 15-2 



Mean 15-2 



Atmospheric air under 1 atm. pressure 



-10 

 -0-2 



+0-1 

 +0-5 

 +0-2 

 +0-2 



-0-6 



13-5 



00 



142 



+0-3 



14-7 



+0-3 



14-7 



+0-2 



14-7 



141 

 14-2 

 14-4 

 14-4 

 14-5 



Carbonic acid under 1 atm. pressure. 





 +0-5 

 + 10 

 10 

 10 

 1-0 



+0-2 



13-2 



0-7 



13-7 



10 



140 



10 



140 



1-0 



140 



13-0 

 130 

 130 

 130 

 130 



Mean. 



14-, 



Mean. 



130 



Atmospheric air under 1 atm. pressure 



Ammonia "under 1 atm. pressure. 



-0-2 

 +1-0 

 + 1-5 



+2-0 

 +2-7 

 +2-2 



+0-4 



150 



+ 1-2 



15-7 



17 



162 



2-4 



170 



2-5 



17-0 



14-6 

 14-5 

 14-5 

 14-6 

 14-5 



-3-2 

 -2-5 

 -20 

 ■ 1-2 



-0-7 

 00 



-2-8 



3-5 



-2-2 



4-0 



-1-6 



4-7 



-10 



40 



-0-3 



60 



6-2 

 63 

 60 

 6-3 



Mean. 



14-5 



Mean. 



Atmospheric air under 1 atm. pressure. 



Marsh-gas under 1 atm. pressure. 



+0-5 

 0-5 

 0-7 

 1-5 

 1-5 

 1-7 



+0-5 



150 



+0-6 



15-2 



11 



15-7 



1-5 



157 



1-6 



16-0 



14-5 

 146 

 14-6 

 14-2 

 14-4 



Mean. 



14-4 



+2-2 

 2-5 

 3-0 

 3-2 

 3-2 

 3 

 2-7 

 2-5 



+2-3 



140 



2-7 



14-5 



31 



150 



3-2 



150 



31 



14-7 



2-8 



140 



2-6 



14-5 



11-7 

 11-8 

 119 

 11-8 

 11-6 

 11-2 

 11-9 



11-7 



Marsh-gas under 1 atm. pressure. 



-1-0 

 0-8 

 10 

 10 

 1-0 

 10 



+0-9 



12-2 



0-9 



128 



10 



12-5 



10 



12-6 



10 



12-6 



Mean. 



11-3 

 11-9 



11-5 

 116 

 11-6 



11-6 



