Ok, it’s not a ruler like I said in my teaser post, but it’s close enough.

Well who doesn’t remember the slide rule? Ok, probably all of the younger generation kids and young adults that call me old, that’s who.
The slide rule was to my surprise, first developed back in the 17th century, I believe in the 1630′s to be exact (to clarify, I’m not that old) by William Oughtred and others. The slide rules popularity continued to grow through the ’50s and ’60s, but it became largely obsolete around 1974 when the digital calculators popularity grew. I was still using the slide rule in high school until it was eventually phased out. Thank goodness for the calculator!
Speaking of the calculator–one of the very first pocket size calculators was the…
Ok, how many of you guessed the Texas Instruments (TI) Scientific Calculator? Well, I thought it was too, so both you and I were wrong, it was the Hewlett Packard HP-35 introduced in 1972, the TI calculator didn’t come out until 1976. If you were one of the early adopters of the HP-35 calculator, you probably paid an arm and a leg for it, or at least close to US$395. Wow! you could buy a full function desktop computer for that much money today.
A little bit of trivia: If I remember correctly, in the 1995 movie Apollo 13, with Tom Hanks, Bill Paxton, Kevin Bacon, Gary Sinise and Ed Harris, I recollect that one of the Nasa engineers was in the background using a slide rule to figure out a mathematical problem.
Now that I’m a lot older and my eyesight isn’t as good as when I was in high school, they have special slide rules just for us.
For more detailed information on the slide rule, check out wikipedia.com:
http://en.wikipedia.org/wiki/Slide_rule





I had a HP-35 and paid $465 for it. That was with security cradle and tax. No HPs were sold without the cradle and none were discounted.
The TI-30 came out in 1976 but there were some Ti’s that came out before it in the early to mid ’70′s.
Whoa! $465 for a calculator, that’s insane, I never realized they were that high. Thanks for the additional information.