Searle's bar method is a method of measuring thermal conductivity.
Searle's bar method is an experimental procedure to measure thermal conductivity of material. A bar of material is being heated by steam on one side and the other side cooled down by water while the length of the bar is thermally insulated. Then
Q = -kA ((T2- T1) / d) t
Where:
Q is the heat supplied to the bar in time t,
A is the cross-sectional area of the bar,
T1 is the temperature nearest the heated end,
T2 is the temperature measured a distance d away from the point of T1 measurement ,
k is the coefficient of thermal conductivity of the bar.
Then energy Q transferred to the cooled end and absorbed by water is:
Q= m Cp (T4- T3) Where
m – mass of water collected during time t
Cp – coefficient of specific heat capacity (specific heat)
T3 is the temperature of water coming from a reservoir,
T4 is the temperature measured as water leaves
http://media.paisley.ac.uk/~davison/labpage/searle/searle.html