One Monday morning in June, I climbed in beside Andrew McDougall, a former bookseller, who drives the bus and manages its books, computer and tapes, as well as organising the children and the teachers - not to mention the author. Off we went, up and down hills with sheep bouncing out of the way and view after stunning view opening before us. The roads were good and the schools, even in the remotest places, were housed in splendid modern buildings, usually adjacent to a leisure centre. The oil industry has had valuable spin-offs.
Despite this, the isolation is very real. Lerwick is Shetland's only town, and its scattered islands have no facilities except a general store serving the far-flung houses, and perhaps a telephone box. The nearest big city is Bergen, in Norway, and the three-day shopping trips offered by P O are popular. Buying books happens mostly through catalogues, but, as one teacher said, "What sounds great in the publishers' description can turn out to be a disappointment. It's so much better to see the books themselves." The Bus stocked a full range of hard-back reference books, picture books and fiction to act as samples which could be ordered through Andrew or the local authority, according to the prevailing system. The Albany Book Company of Glasgow provided the books, all chosen from the publishers' latest lists, and there were also paperbacks for immediate sale, nothing costing more than five pounds.
Some teachers and librarians felt that the Bus should not stock Point Horror books, but Andrew argued that it is better for children to read anything than nothing. The children themselves seemed to regard these shockers as collectable objects rather than real books. One girl complained they were full of typographical errors, and wanted to know how this could happen.
The biggest sellers of all were Canongate Kelpies, at a knock-down price of 50 pence. Children are not slow to spot a bargain. Age, I noticed, had little to do with reading ability; quite small children could be engrossed in Anne Fine while some of the older ones were happy to laugh over pop-up books.
At each school, while Andrew was setting up his display and getting the computer linked to a power supply, I'd go in and talk to the children for an hour (or sometimes two), telling stories and showing them books, explaining what lay behind them and how they came to be written. The children were unfailingly courteous even though they were often very excited, but there were times, especially on the easterly island of Whalsay, when it was hard to understand the dialect.
Shetland is intensely Nordic, and not only in speech. The people look as strong and vigorous-haired as the ponies that roam across the unfenced roads, and when we had been up through Yell and across the next ferry to Unst, the landscape suddenly changed to a wilderness of boulders and watery inlets, more Icelandic than like anything in Scotland, which Shetlanders call "the south".
The Book Bus schedule was tight-packed, a strong contrast with the leisured pace we found in the schools. One headmaster, catching up belatedly with his paper-work, interrupted my session with the children by means of a long Tannoy exhortation to be quiet in the area round the library, as an author would be coming . . . the children smiled, but were not surprised. There was a general air of faint distractedness, partly because it was the end of term, but perhaps also because of the "simmer dim", when at midnight, the sun still glows from just below the horizon, and everything is magically clear.
A week later, I joined the bus again, in the tougher and grubbier setting of Renfrew. Term had ended, and the children who came did so voluntarily, few of them accompanied by parents, none with any money. They were cheekier than the young Shetlanders, and sharper, though less inclined towards serious reading.
I realised again how the city breeds restless, wary children, lacking the peace of those who look to the long line of the horizon and the sparkle of water in the voe - yet these children, too, could stop for a moment and become caught by the secret world of a book. Some played with the computer, but Andrew said that of all the thousands who had been through the bus, only one had known how to pursue the CD ROM programme and few showed more than a passing interest in it.
If the Readiscovery campaign has proved anything, it is that the need for books remains a fundamental one. Long may it last.
Alison Prince's forthcoming children's book, The Sherwood Hero, will be published in December. The Book Bus is sponsored by the Bank of Scotland as part of the Readiscovery Campaign. Further details from the Readiscovery Campaign, The Scottish Book Centre, 137 Dundee Street, Edinburgh EH11 1BG.