Herron, page 17: "On the street below, a milk float rattled past."
It seems fairly obvious that a milk float is some sort of conveyance for milk, but as with many things that a writer thinks everyday enough to need no further explanation, we don't really get a clear picture of it if we've never seen one. We don't have milk floats in the U.S., or I should say in my part of the U.S. We do have floats, but they usually associated with parades, like homecoming parades, the Rose Bowl parade or the Macy's Thanksgiving parade. Milk when it used to be delivered, was delivered in trucks, or before that in wagons. So I'm not sure what a milk float is closest to, but the phrase conveys odd images to my mind.
|horse-drawn milk float in Montreal, 1942, Conrad Poirier|
So what is a milk float? Wikipedia tells us that in Great Britain (and some other European countries), milk floats are vehicles run on electric batteries, though formerly they were horse-drawn wagons. Being electric, they are pretty quiet, despite the two descriptions above, which I think must refer to the milk bottles clanking around and not the sound of the milk float itself.
|a milk float in Liverpool, 2005 Tagishsimon|
Sometimes, they have an enclosed area in the back which keeps the milk colder, like this one:
|Dairy Crest Ford Transit,Oxyman|
Although I believe this last is actually a diesel operated truck, not an electric vehicle. As in the U.S., door to door delivery from local dairies has declined thanks to more places people can just go buy milk nearby, but home delivery does still exist. The routes are just longer, requiring higher powered vehicles.
I think the idea of slow moving milk floats progressing (mostly) silently through the neighborhood in the early hours of the morning is pretty cool. If you do too, you can check out a website called Milk Float Corner, where you can find out more about milk floats, watch videos and read the FAQs.