pecific heat of superheated steam
at various pressures and temperatures is given in tabulated form in
Table 25. These values have been calculated from Marks and Davis Steam
Tables by deducting from the total heat of one pound of steam at any
pressure for any degree of superheat the total heat of one pound of
saturated steam at the same pressure and dividing the difference by the
number of degrees of superheat and, therefore, represent the average
specific heat starting from that at saturation to the value at the
particular pressure and temperature.[21] Expressed as a formula this
calculation is represented by

H_{sup} - H_{sat}
Sp. Ht. = ----------------- (8)
S_{sup} - S_{sat}

Where H_{sup} = total heat of one pound of superheated steam at any
pressure and temperature,
H_{sat} = total heat of one pound of saturated steam at same
pressure,
S_{sup} = temperature of superheated steam taken,
S_{sat} = temperature of saturated steam corresponding to the
pressure taken.

TABLE 25

MEAN SPECIFIC HEAT OF SUPERHEATED STEAM
CALCULATED FROM MARKS AND DAVIS TABLES
_______________________________________________________________
|Gauge | |
|Pressure | Degree of Superheat |
| |_____________________________________________________|
| | 50 | 60 | 70 | 80 | 90 | 100 | 110 | 120 | 130 |
|_________|_____|_____|_____|_____|_____|_____|_____|_____|_____|
| 50 | .518| .517| .514| .513| .511| .510| .508| .507| .505|
| 60 | .528| .525| .523| .521| .519| .517| .515| .513| .512|
| 70 | .536| .534| .531| .529| .527| .524| .522| .520| .518|
| 80 | .544| .542| .539| .535| .532| .530| .528| .526| .524|
| 90 | .553| .550| .546| .543| .539| .536| .534| .532| .529|
| 100 | .562| .557| .553| .549| .544| .542| .539| .536| .533|
| 110 | .570| .565| .560| .556| .552| .548| .545| .542| .539|
| 120 | .578| .573| .567| .561| .557| .554| .550| .546| .543|
| 130 | .586| .580| .574| .569| .564| .560| .555| .552| .548|
| 140 | .594| .588| .581| .575| .570| .565| .561| .557| .553|
| 150 | .604| .595| .587| .581| .576| .570| .566| .561| .557|
| 160 | .612| .603| .596| .589| .582| .576| .571| .566| .562|
| 170 | .620| .612| .603| .595| .588| .582| .576|