Re: Watt's definition of horsepower

[Rick Tarara <rbtarara@SPRYNET.COM>]

My understanding (but I have no idea from where) was that the 'horse' in
question was a draft horse (Clydesdale type).  It takes a BIG horse to
generate 1 horsepower.  I had assumed (or maybe read) that they simply
hooked up such a horse to a rope/pulley and measured how much weight the
horse could lift over a measured distance in a given time.  However, a quick
search on the Web and a trip to the ENCARTA site yields:

"Scottish engineer and inventor James Watt established this value for the
horsepower after determining in practical tests that horses could haul coal
at the average rate of 22,000 foot-pounds per minute. He then arbitrarily
raised this figure by a factor of one-half to establish the current value."

Rick

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Richard W. Tarara
Associate Professor of Physics
Department of Chemistry & Physics
Saint Mary's College
Notre Dame, IN 46556
219-284-4664
rtarara@saintmarys.edu

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----- Original Message -----
From: "Kim S. Palermo" <kpalermo@OPTONLINE.NET>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, December 06, 2000 8:07 PM
Subject: Re: Watt's definition of horsepower


> My understanding is that it was the work a horse could do in one day.
>
> Kim Palermo
> Physics/Chemistry Teacher
> Southold UFSD
> Southold, NY
>
>
> Tim O'Donnell wrote:
> > My textbook states Watt basically said a horsepower is the rate of
> > work a horse can do for a sustained period of time. Any clue to what
> > would be considered a sustained period of time?
> >
> > Tim O'Donnell
> > Instructor of Physics and Chemistry
> > Celina High School
> > 715 East Wayne Street
> > Celina, Ohio 45822
> > (419) 586-8300 Ext 1200 or 1201
> > odonnt@celina.k12.oh.us
> >
> > "Chance only favors the prepared mind." - Louis Pasteur