  The magnetocaloric properties of three samples of LaFe$_{13-x-y}$Co$_x$Si$_y$
have been measured and compared to measurements of commercial grade Gd. The
samples have (x=0.86, y=1.08), (x=0.94, y=1.01) and (x=0.97, y=1.07) yielding
Curie temperatures in the range 276-288 K. The magnetization, specific heat
capacity and adiabatic temperature change have been measured over a broad
temperature interval. Importantly, all measurements were corrected for
demagnetization, allowing the data to be directly compared. In an internal
field of 1 T the maximum specific entropy changes were 6.2, 5.1 and 5.0 J/kg K,
the specific heat capacities were 910, 840 and 835 J/kg K and the adiabatic
temperature changes were 2.3, 2.1 and 2.1 K for the three LaFeCoSi samples
respectively. For Gd in an internal field of 1 T the maximum specific entropy
change was 3.1 J/kg K, the specific heat capacity was 340 J/kg K and the
adiabatic temperature change was 3.3 K. The adiabatic temperature change was
also calculated from the measured values of the specific heat capacity and
specific magnetization and compared to the directly measured values. In general
an excellent agreement was seen.
