On Mon, 21 May 2007 18:47:48 +0100, Martin Gregorie
wrote:
[snip]


Possibly irrelevant, but I remember seeing a Scientific American article
back in the late 60s/early 70s on this topic. I forget what triggered it
(possibly a comment on a back to nature movement) but it pointed out
that even then it would be impossible to replace America's oil-powered
transport systems with horses because there wasn't the farm land in the
USA to feed the horses, let alone produce anything else.

That's not the only reason. The city of San Francisco spent a load of
money to install a cable-car transit system in the early 1870s. They
knew electric cars would be available in ten years, but SF couldn't
wait. Its horse population had grown to the point of depositing 55,000
gallons of horse **** on the streets per day, along with the
proportionate quantity of road apples. The constant wheel and foot
traffic mixed it up into a ghastly morass that lubricated the
cobblestones, causing the horses to slip and break legs. At one point
the city was shooting an average of one horse per day.

Other major cities were able to hold out until they could get electric
cars, because they didn't have San Francisco's steep hills, but they
still had stink and disease to deal with. Horse transport simply
becomes intolerable past a certain traffic density.

rj