Gene Nygaard wrote:
"Those "pounds weight are an obsolete term for what are now called
pounds force."

Spoken like a weight-loss promoter.

Good mathematics becomes obsolete very slowly. Archimedes found the
approximate value of pi in the 3rd century before Christ.

Archimedes inscribed the largest regular polygon ithat would fit inside
a circle. Next he drew outside the circle a similar regular polygon
touching the circle on all sides and having its sides parallel to the
polygon sides inside the circle. Then he increased the number of sides
of his polygons until they totaled 96. He decided a 96-side,
equal-sided, figure was close enough to a circle for practical purposes.
He also knew that a real circle would have a circumference somewhere
between the circumferences of his inside and outside polygons. Also, the
circumferences of his inside and outside figures were very nearly the
same anyway.

The tape measure must not have yet been invented, so Archimedes must
have measured the sides of his figures with a straight ruler. He used
the sums of the polygon sides to arrive at the circumference of his
figures. From these constructions and measurements, Archimedes arrived
at a figure of 3.1416 for the ratio of circumference to the diameter of
a circle (pi). That`s still close enough for most purposes to this very
day.

There was a PBS special here today on "The Method" one of the books
written by Archimedes, a copy of which was recently sold at auction for
2 million dollars.

Archimedes was slain in his laboratory by a Roman soldier in spite of
orders that he be taken alive and transported to Rome. He was the top
Greek war machine designer.

Best regards, Richad Harrison, KB5WZI