Thermal conductivity ofHe4I from nearTλto 3.6 K and vapor pressure to 30 bars

We present new data for the thermal conductivity of liquid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ along isotherms from 2.1 to 3.6 K, covering the pressure range from vapor pressure to 30 bars, and along isobars from vapor pressure to 28 bars, covering the reduced-temperature range 2×${10}^{\mathrm{-}6}$≲t [=(T-$T_{\lambda }$)/$T_{\lambda }$]≲0.1. Measurements in several cells with spacings from 0.0025 to 0.453 cm revealed no anomalous size effect. For t≳${10}^{\mathrm{-}3}$, the accuracy of the data is 0.2% to 0.3%. Closer to $T_{\lambda }$ systematic errors due to uncertainties in boundary-resistance corrections gradually increase with decreasing t, and reach about 2% near t=2×${10}^{\mathrm{-}6}$. With decreasing t≲${10}^{\mathrm{-}4}$ random errors due to finite temperature resolution increase also, and reach about 2% near t=2×${10}^{\mathrm{-}6}$.