In 1980, G. I. J. Orton wrote a history of Mobile Libraries in the U.K. His definition of what a "Mobile Library " is, involves the use of the "Internal Combustion Engine". Prior to the use of vehicles into which people could walk and choose books, boxes of books were taken around to villages, branch libraries, schools, or even family homes. We would call these deposit collections. They were known as "Traveling Libraries" and were commonly delivered by horse and cart. This means that the "mobile" camel library, or elephant library are not "Mobile Libraries " in Orton's sense of the word. In the early 1900's, Staffordshire circulated boxes of books for local populations, around library centres based in Schools. there were 50 books available, thirty of which circulated and 60% were children's books. Orton does not specify which Baltimore he means, but apparently in a Baltimore during 1943, the horse and cart delivery was reinstated because children found it preferable. there had been "Juvenile Delinquent " problems there.
The terms for a library that moves have been variously known as "Circulating Libraries", "Traveling Libraries", "Bibliobus", "Library Coach", "Book bus" and of course in America they are know as "Bookmobiles". In 1920's Britain a van that people could enter and browse books on shelves were known as "Exhibition Vehicles". The 1925 one from Norfolk contained one third Juvenile Fiction. It appears that the idea of mobile libraries didn't really take off until the second world war. Hastings owned a mobile library van, but because of pressures during wartime (not specified) it was put up for loan. the Borough of St Pancras adopted it and it carried a "Good choice of children's books". I 1954, only 10% of all U.K. mobile libraries carried children's books. Vehicles were sometimes put to use for children.
In 1958 Nottinghamshire used two vehicles in the summer holidays to visit villages with a Children's librarian. By 1966 the idea had blossomed and most local authorities offered the same service. Caernarvonshire used one in1961 to take a termly supply of books to schools but it was also used to transport books to branch libraries. Specific vehicles for children did not emerge until the 1960's. Possibly the first child specific mobile library was produced in 1963 by Moray County Library. It functioned specifically for primary age children, carried 200 books and had sufficient room for 36 children (a classful) and their teacher. Schools were visited fortnightly and each class allowed 20 minutes to choose their books. Local government boundary reorganisation paused the development of all mobile libraries for a while, so the next stage comes in the 1970's.
the summer of 1975 appears to be the year of the Children's mobile library. Leicester County Libraries converted a corporation double decker bus into a "Magic Mobile Library" to tour the "Non-reading" parts of Leicester. It was decorated with witches, goblins and ghosts, aimed to serve under 14's and their parents. It stayed in places for about an hour, showing films, holding competitions and story times. I was in Leicester at that time, but I don't ever remember seeing it. Southampton had a pink "Book bus" charged with the mission to break down barriers between children and libraries. It's raison-detre was as community liaison, not just to deliver books. I think that is the aspect of mobile libraries that local government politicians and accountants fail to perceive. They are community assets, they are "ideal publicity machines" for local authorities (Orton 1980) they socialize and link disparate communities. Back to the summer of '75...
... Hammersmith brought out the "Pied Piper that visited 18 schools, and in 1976, Shropshire had a less formal pied piper too. As Orton was writing in the late 70's , that is where this story ends. He finished by stressing that economic pressures and increasing fuel costs were presenting problems for mobile library services. Well there is no change there then.