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Log Tables

lostmyway

While I have a good idea how log tables work, I'm still in the dark as to how they are compiled.

I gather some bloke name 'Napier' originally invented them but what method did he use?

Any mathematicians' contributions would be appreciated. 

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  • lostmyway said:

    OK, for instance, how would I work out the log of 50 to base 10?

    Easy if you know what log 2 is which is .3010 (to four decimal places)

    Subtract this from log 100 which makes 1.6990

    (You can then work out a few other logs, such as Log 5, Log 8, Log 16, Log32, Log 25, Log 12.5, etc)

    But the hard part is calculating log 2 rather than looking it up in a table .... as you need to know what power to raise 10 to make 2! Easy with a computer but very difficult and time consuming without!

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  • lostmyway said:

    OK, for instance, how would I work out the log of 50 to base 10?

    Easy if you know what log 2 is which is .3010 (to four decimal places)

    Subtract this from log 100 which makes 1.6990

    (You can then work out a few other logs, such as Log 5, Log 8, Log 16, Log32, Log 25, Log 12.5, etc)

    But the hard part is calculating log 2 rather than looking it up in a table .... as you need to know what power to raise 10 to make 2! Easy with a computer but very difficult and time consuming without!

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