Message text written by Bruce Marcham
>I would
think that the losses and maintenance associated with spinning all those
long shafts and belts had to be pretty high.<

Also dangerous--I have read of workmen being killed by a belt or shaft that
broke loose. 

When I was in 7th-8th grade in Thomaston (Maine) Grammar School, at the
home of one of my friends was the remains (in the "barn" which there means
anything bigger than a toolshed) of his grandfather's woodworking shop.
Most of the machinery was gone but the overhead shaftwork remained in
place. Apparently the motive power (at least in the shop's final form) was
a big electric motor. Interesting to consider the change in thinking it
would take to go from one power source for everything, to individual power
sources. The actual power source might vary--water, steam engine, gas
engine, electric motor--but there is a conceptual difference in having each
device independently powered. Much the same thing happened with computers,
which were once so large and expensive that the idea was to have one
computer doing a lot of jobs, maybe even for a lot of locations at once. My
first contact with computers was a terminal at my high school in Maryland
1968 (then considered a very modern innovation for a high school to have),
connecting to a mainframe in North Carolina. Through the 70s, the
predictions were that we would have such terminals in our homes, or maybe a
big computer lurking like a furnace in the basement of the house, which we
would tap into for all sorts of uses. As with the power sources for machine
tools, the change to having lots of small computers doing individual jobs
was brought about by their decreasing cost and power to size ratio. The
laptop computer on which I write this has more computing power than the
most powerful mainframe computer did in 1968, and tiny computers are
everywhere, it seems in every electronic device. 

Incidentally, the earliest internal combustion engines were designed to
take the place of small steam engines in those stationary applications such
as powering machine shops, and the shaft-and-belt systems were the source
of the earliest forms of clutches, transmissions and other devices adapted
into the drive trains of the earliest internal-combustion-powered
automobiles (steam or electric cars do not need clutches or transmissions).


        ----Sign me, Inside the Beltway

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