Letter from J [John] Brown, Longhurst, Dunmurry, Belfast, to [Joseph] Larmor Brown tried cooling the tube with liquid air, with about a tenth of the lower tube immersed, but nothing happened. There was no change in the difference and potential of copper and zinc plates, or if anything a slight rise, probably an experimental error. This requires thought; he got the air in Dublin. Moss suggested that 'it was unlikely the atmosphere of a Fenian place like that could be taken to the Orange North with any hope of success'. 19 January 1902