Detached Thermom. above

76°.
Detached Thermom. below

68.0

———
Whole Heat

144.0
Half Heat

72.0

 (0 adding a Cypher)
Standard-Heat

31.24
which deduct, and there
remains

———

40.76:

with which, by the 4th Table, find the Expansion of Air on Feet 81.73:

First, with 40°, on 81.73, thus:

on 80.

 as 8000

777.6 =

 7.776

1.

 as 1000

97.2 =

 .0972

.7

 as 7000

680.4 =

 .06804

.03

 as 3000

291.6 =

 .002916
————
7.944156
Second, with .76 on 81.73, thus:

on 80.

 as 8000

1477.4 =

 .14774

1.

 as 1000

184.6 =

 .001846

.7

 as 7000

1292.7 =

 .0012927

.03

 as 3000

554.0 =

 .0000554
————

Expansion

 .1509341
add the former Expansion 7.944156
————
Sum of the Expansions, viz.
Height in Feet
from Excess of Heat above
Standard, with 40°.76 on 81.73,		 8.0950901
added to the Height at the
Standard-Heat, in Feet		 81.73
————
gives, in Feet and Tenths, the true
Height of the Tarpeian Rock		 89.8|2.

CHAPTER LXXIX.

A CALCULATION TO ASCERTAIN THE HEIGHT OF THE BALLOON ON THE DAY OF ASCENT: ONE BAROMETER AND ONE THERMOMETER ONLY, BEING TAKEN UP INTO THE CAR.

Section 423. THE Question is stated from Section 36: and the Mode of Operation taken from the Recapitulation of the second Example, Section 409.

Observation before the Ascent:

Below: Barometer 29.8; attached Thermometer 0; detached Thermometer 65°.

Above: Barometer 23​1⁄4 = 23⁠25⁄100 or 23.25⁠[135] attached Thermom. 0; detached Thermom. 65°.