In brief, Edison’s storage battery cells are composed of tiny bricks of specially-prepared iron and nickel. In charging and discharging, oxygen is driven from one metal to the other and back again through the action of a potash solution, and without corrosion or waste. Renewal of the water supply is all that is needed to keep the cells in good condition, and a process of recharging has been improved, so that less time is consumed than for the recharging of other batteries. No wonder he believes that the application of storage batteries will ultimately be extended to trains, and especially to ships. The claim of the Edison Accumulator is that it will occupy about the same space as the present battery, and that it will weigh only about seventy per cent. as much, and will be more durable. Men conversant with the theory of electrical science are not so thoroughly impressed with the work accomplished as is Mr. Edison. The tests that have been made have been more than duplicated, it is said, by the batteries now on the market. We may assume, then, that either Edison’s or somebody else’s method of storing up electricity for the propulsion of sea-going vessels will be perfected. [Illustration: FIG. 34. ELECTRIC STORAGE BATTERIES _By permission of the_ _Electric Power Storage Co., Ltd., London_] THE “PRINCESS IDA” IN THE YEAR A.D. 19-- Early one morning in the spring of 19--a small party of ladies and gentlemen, anxious to avoid the east wind fiend by flying from their native shores to milder regions, travelled by the electric railway towards the mouth of the Thames, and, branching off at a point near Barking Junction, traversed the new line, running for miles alongside the splendid quays recently completed between Galleon’s Reach and Tilbury, where special berths were reserved for the leviathan liners that had begun running from the port of London to Cape Town. Long before the station was reached inquiring glances had been cast riverwards for the first glimpse of the giantess _Princess Ida_. “That cannot be the _Princess Ida_,” said an unbelieving and short-sighted member of the party to his sharp-eyed friend, who was pointing to something which in the distance looked like a couple of White Star _Cedrics_ linked together and towering above the roofs of the warehouses that commanded the quays. “Well, you will see for yourself presently,” he retorted. “Seeing is believing, isn’t it?” And as the train got nearer and nearer, wonder and admiration increased, and when a break in the line of warehouses gave them a clear view of the great vessel, her beautiful proportions, her polished hull gleaming in the sunlight, and her exquisite cleanliness, their excitement and enthusiasm rendered them speechless.