from the bottom of tank 20 is open at its submerged bottom end in the water above the nearest approach of the magazine to the block electrode fig1 also shows cylinder 21 inert flushing gas with valve 22 connected by tubing 23 to the upper end of magazine 24 which is capable of holding at least several carbon rods and is covered by cap 25 except during loading of the rods fuel transport tube 32 connects the top of gas collecting hood 30 through in line isolation valve 33 and compression pump 39 to three way distribution valve 39 which may be closed open to upper branch line 4 or open to lower branch line 41 the upper branch line leads from the distribution valve to coupling 5 of fuel gas storage container 6 having pressure valve 7 thereon successive containers may be connected to the line for filling and be disconnected therefrom for storage when filled lower branch line 41 from distribution valve 39 leads to the top of condenser 40 inside insulating jacket 45 where it connects to the top end of helical condenser tube 43 whose bottom end connects via outlet tube 49 to liquid fuel container 60 the helical tube is surrounded by condenser jacket 42 which has vent tube 41 at its upper end and is supplied at its lower end with coolant from tank 50.