analog computer – my slide rule

I blew the dust off this slide rule which I uncovered earlier this week in a drawer full of tucked away items. This is not the one I used in high school to solve Boyle’s Law Gas problems in Grade 12 Chemistry.  This is a small give-away slide rule that my late father’s company gave away.  You can probably read Canadian Bechtel Ltd. Safety Recognition.  When I was growing up there were numerous items around the house, usally Parker T-Ball Jotter ball point pents with “We believe in safety” marked on them and the Canadian Bechtel logo “bug” as well.  I learned how to run a slide rule in the first semester of Grade 12 at an optional after school tutorial run by my chemistry teacher, Fr. David Beaudois, S.J., at Brebeuf College School, in Willowdale, Ontario.  Willowdale may be an obsolete reference for the area of the school.  It was on Steeles Avenue and west of Bayview Ave. at the top of North York in Toronto.

Boyle’s Law from Wikipedia:

The mathematical equation for Boyle’s law is:

\qquad\qquad pV = k


p denotes the pressure of the system.
V denotes the volume of the gas.
k is a constant value representative of the pressure and volume of the system.
In solving the advantage ofg using a slide rule is that you could bsically ignore the result of the first step of the calculation and just move the slide rule to get to the final answer. About ten of us out of 30 took Fr. Beaudois up on his offer to show how to run the slide rule and so we gained an advantage in speed in solving gas problems. 
This was the shining moment of my science education.  The first semester examination had a lot of gas problems on it, but I must have been tune in that term because I had the top mark inGrade 12, a 57 out of 60 on the exam.  We will race past how poorly I did in Grade 12 mathematics.  I had never really had to study math until that year and I suddenly ran into the brick wall of confusion and did miserably.  To this day I have a bit of math phobia.
That was all in 1971.  Looking up slide rules this morning on Wikipedia I discovered that scientific calculators becam available to consumers. albeit at a hefty price, in 1974.
I also learned that Americans sometimes referred to slide rules as slipsticks.  They were developed based on the logarithm work of John Napier back in the 17th century by William Oughtred and others.Image

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