92 B. V. Marsh on the Luminosity of Meteors. 
Arr, XIII.—Remarks on the Luminosity of Meteors as affected by | 
Latent Heat; by BeNJAMIN V. MarsH. 3 
Saererently adopted by the author mainly for the purpose of 
exp 
serve these meteors at elevations of 140 to 160 miles; they im 
crease in brightness as they approach the earth; they disappear 
entirely as they approach the lower part of the atmosphere, a8 
if they entered a medium which had not the elements necessary 
fourth region of fire above the solid, liquid, and gaseous com 
stituents of our globe. In fact, above the region where the aif, 
the particles of matter, being very widely separated, condense 
around them the largest amount of ether. All sensible heat, 
and may be capable of producing the most splendid igneous 
phenomena, like the northern lights, or tropical thunder storms” 
“If a unit of weight of any gas, allowed to expand fre 
without change of pressure, is heated from the freezing Pp 
ne degree, the amount of heat thus absorbed, measured in /r 
tions of the unit, is called ‘the specific heat under constant 
sure.’ If the same gas is heated one degree when so cor 
| ‘Svensk, MA Ge (Bogland), ae by . 
