« PreviousContinue »
STATEMENT OF THE OBJECT OF THE WORK,
have not the same intensity. The intensity of each ray is proportional
1 Each paragraph of the Table indicates the matter treated of in the articles
to the cosine of the angle which its direction makes with the normal to
GENERAL NOTIONS AND PRELIMINARY DEFINITIONS.
40–49. First notions of radiant heat, and of the equilibrium which is
established in spaces void of air ; of the cause of the reflection of rays
57–59. When two molecules of the same solid are extremely near and at
unequal temperatures, the most heated molecule communicates to that
60. When a heated body is placed in an aeriform medium at a lower tem.
perature, it loses at each instant a quantity of heat which may be
temperature of the surface over the temperature of the medium
LAW OF THE PERMANENT TEMPERATURES IN A PRISM OF SMALL THICKNESS.
THE HEATING OF CLOSED SPACES.
81–84. The final state of the solid boundary which encloses the space
heated by a surface b, maintained at the temperature a, is expressed by
the following equation :
m -- n=(a − n)
The value of P is
+ + )
m is the temperature of the internal
air, n the temperature of the external air, g, h, H measure respectively
boundary, and K its conducibility proper .
85, 86. Remarkable consequences of the preceding equation .
87–91. Measure of the quantity of heat requisite to retain at a constant
temperature a body whose surface is protected from the external air by