10 Prof. R. Bunsen on a Method of determining the 



On noticing that the temperature begins to vary from o- l to 

 o, 2, it is sufficient, in order to regain the original temperature, 

 slightly to move one of the lamps. That this is the case may be 

 seen from the following observations, in which neither the stop- 

 cock was altered nor any special regulator employed. 



First arrang 



•ement of the 



Second arrangement of the 



lamps. 





lamps. 



li m 



o 



h 



m 



o 



8 



7-0 C. 



10 







143-0 C. 



5 



55-0 





5 



144-6 



10 



93-8 





10* 



144-9 



15 



111-8 





15 



144-7 



20 



119-6 





20 



144-4 



25 



122-2 





25 



144-1 



30 



1231 





30 



144-5 



35 



1233 





35 



144-5 



40* 



123-4 





40 



144-4 



45 



123-3 





45 



144-4 



50 



123-2 





50 



144-4 



55 



123-2 





55 



144-3 



9 0* 



123-4 



11 







144-3 



5 



123-2 









10 



123-2 









15 



123-2 









20* 



123-4 









25 



123-5 









30 



123-2 









35 



123-2 









The vessels to be placed in the thermostat are filled in different 

 ways, according as a gas or a vapour is being examined. Gases 

 are filled in as follows : — 



The vessels III. and IV., which are to receive the gas and dry 

 atmospheric air, are placed in the thermostat, where they rest on 

 a wire frame and are surrounded on all sides by a layer of air. 

 The thermostat is then closed with its cover, and the holes from 

 which the capillary tubes of the vessels project are stopped up 

 by corks or cylinders of chalk, which have first been bored 

 through, and then cut up from end to end, so as to form two 

 halves capable of sliding over each other. A thermometer for 

 observing when the temperature becomes stationary is placed in 

 the third hole, which is closed up in a similar manner. The 



temperature, thermostats like the one here described, in which the heat is 

 introduced from the sides. 



* The asterisks denote the times when an alteration in the lamps was 

 required. 



