Slide rules

[Samblain]

How does a slide rule work Can you still get them

[SteveD]

Sorry, I have no idea how to use one, but there are plenty for sale on E-bay: http://search.ebay.co.uk/slide-rule_W0QQsoloctogZ9

[Ewood27]

They have what I think is a logarithmic scale printed on them. If you put, say, 1 on the slider (middle bit) against 3 on the outer scale, every number on the inner scale will be lined up with the number three times that number on the outer scale (if that makes sense). So you will now find 3 against 9, 5 against 15 and so on.

[New Forester]

The effect of the logarithmic scale is that by adding numbers on the slider, you get the multiplied answer on the other. You can also divide by subtracting. They usually also have linear scales for addition, and other scales for sine, cosine, etc. And it's only 25 years or so since I saw one...

[BenDToy]

I only threw mine out about 18 months ago, but I can't for the life of me remember how to use one!