circa

fleetは当時はこんな意味で使われていたんだね。busもomnibusだったのか。なんだかとても懐かしいと感じるのはわたしだけでしょうか？ところで、故山本くん、circaってなんだろうか？circadianは前にもとりあげましたが...（UG）
http://d.hatena.ne.jp/A30/20101013/1286917497
　　　　
The London Bus Story by John Christopher recounts the history of one of London's most famous icons. The first bus service was launched in 1829 by coach-builder George Shillibeer, who was inspired by a similar service in Paris. His small fleet of horse-drawn vehicles quickly spawned many imitators and by the turn of the century, vehicles owned by the London General Omnibus Company (LGOC) dominated the scene. Here is a typical LGOC bus circa 1910, in Piccadilly Circus.
http://www.telegraph.co.uk/expat/expatpicturegalleries/8338479/The-London-bus-story.html