JB/106/065/003

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Qu. The degree of Conducting Power; & heat conducted

1. In the Case of Ice, which will always remain of one uniform temperature.
Quiescent State must be the following in a substance of uniform conducting power.

N.B. The no.s express the excess of the temperature above y+ of ice.
Air |

20o=A |19o|18o|17o| 16o|15o|14o| 13o|12o|11o |10o|9o|8o |7o|6o|5o |4o|3o|2o|1o| 0o=B

Let the higher temperature, viz.y+ of the air be = A
the lower - - - or y+ or y- ice = B

C=Conducting Power
S.=surface

Their difference = A - BD B = D

Difference in temperature between two contiguous minute strata = d

Number of Strata = N .=. thickness of the conductor.

Time necessary for the equilibrium being restored between two contiguous
strata; that is for the transmission of d/2 of heat in the direction of
from A to B, = t H = heat communic.d during the time T given.

Let t be .=. 1/d which is probably the law of communication of
temperature

H .=. d/2 & 1/txCs but t .=. 1/d therefore H .=. SddC .=. D2CS/N2

Therefore the heat transmitted thro' any conducting substance of uniform
structure is as the conducting power multiplied by the square of the
difference of temperature between the two bodies which maintain their heat
temperature - directly,

And as the squares of the thickness of the conductor inversely

It is also directly as the surface, that is or as the square of ye diameter

—

Probably the same formula applied to the other cases as well as to this.

By the help of this formula it would perhaps be easy to
calculate the quantity of ice required for y- annual stock - by a few
direct experiments.

N.B. The formula also furnishes an easy method of
ascertaining the conducting powers of bodies with great precision
as the different capacities of bodies for heat will influence the experimt.

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Identifier: | JB/106/065/003"JB/" can not be assigned to a declared number type with value 106.
Date_1	1795	Marginal Summary Numbering
Box	106	Main Headings	frigidarium
Folio number	065	Info in main headings field
Image	003	Titles	sources of cold / sources of heat / economy of temperature
Category	copy/fair copy sheet	Number of Pages	3
Recto/Verso	recto	Page Numbering	f2 / / /
Penner	fr4	Watermarks	pot 1796
Marginals		Paper Producer	fc6
Corrections	jeremy bentham	Paper Produced in Year	1796
Notes public		ID Number	34653
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