Design data and constructional details are given for a small water-cooled solenoid, which, for a consumption of 100 kw. produces a field of 14.7 kilogauss, uniform to within ±½% in a cylindrical volume 6 cm. long and 4 cm. diameter. The solenoid contains no iron or other ferromagnetic material, and is in use at the Clarendon Laboratory, Oxford, for experiments on adiabatic demagnetization.