The Coming Race by Edward Bulwer-lytton

As we walked back to the town, Taee took a new and circuitous way, in order to show me what, to use a familiar term, I will call the 'Station,' from which emigrants or travellers to other communities commence their journeys. I had, on a former occasion, expressed a wish to see their vehicles. These I found to be of two kinds, one for land journeys, one for aerial voyages: the former were of all sizes and forms, some not larger than an ordinary carriage, some movable houses of one story and containing several rooms, furnished according to the ideas of comfort or luxury which are entertained by the Vril-ya. The aerial vehicles were of light substances, not the least resembling our balloons, but rather our boats and pleasure-vessels, with helm and rudder, with large wings or paddles, and a central machine worked by vril. All the vehicles both for land or air were indeed worked by that potent and mysterious agency.

I saw a convoy set out on its journey, but it had few passengers, containing chiefly articles of merchandise, and was bound to a neighbouring community; for among all the tribes of the Vril-ya there is considerable commercial interchange. I may here observe, that their money currency does not consist of the precious metals, which are too common among them for that purpose. The smaller coins in ordinary use are manufactured from a peculiar fossil shell, the comparatively scarce remnant of some very early deluge, or other convulsion of nature, by which a species has become extinct. It is minute, and flat as an oyster, and takes a jewel-like polish. This coinage circulates among all the tribes of the Vril-ya. Their larger transactions are carried on much like ours, by bills of exchange, and thin metallic plates which answer the purpose of our bank-notes.