[ 96 | 
Lamp with {mall ftopper, 
Temperature of mereury 126, 
Trerements of 
Minutes of obferyation, Temperatures, Temperature in a miayee: 
> ” i 79 « 45 
> Been keel) Eh ae 
=== 129 in 3%, 
Tavs it appears, that, in lemps made on this conftruction, the 
internal aperture for alr may be confiderably diminithed with advan- 
tage, What fs the moft edvantageous opening I have not had 
leifure to determine, It is probable it would not bear to be 
 diminifhed much more than jn the experiment laft recited, 
