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 time to look at the address, place them in the proper box, and touch the spring which sets the electric current at work. If secrecy were needed a cipher would easily secure it, for you will observe that by this telegraph whatever is inscribed on the sheet is mechanically reproduced; and it would be as easy to send a picture as a message."

I learnt that a post of marvellous perfection had, some thousand years ago, delivered letters all over Mars, but it was now employed only for the delivery of parcels. Perhaps half the commerce of Mars, except that in metals and agricultural produce, depends on this post. Purchasers of standard articles describe by the telegraph-letter to a tradesman the exact amount and pattern of the goods required, and these are despatched at once; a system of banking, very completely organised, enabling the buyer to pay at once by a telegraphic order.

When Esmo had finished his business, we walked down, at my request, to the port. Around three sides of the dock formed by walls, said to be fifty feet in depth and twenty in thickness, ran a road close to the water's edge, beyond which was again a vast continuous warehouse. The inner side was reserved for passenger vessels, and everywhere the largest ships could come up close, landing either passengers or cargo without even the intervention of a plank. The appearance of the ships is very unlike that of Terrestrial vessels. They have no masts or rigging, are constructed of the zorinta, which in Mars serves much more effectively all the uses of iron, and differ entirely in construction as they are intended for cargo or for travel. Mercantile ships are in shape much like the finest American