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Re: napier and logarithms
From: Paul Hirose
Date: 2009 May 29, 21:12 -0700
From: Paul Hirose
Date: 2009 May 29, 21:12 -0700
corallina wrote: > I worked the sqrt of 100000 in about 2 hours. How did you do it? As a schoolboy I was taught a method similar to long division, but all I can remember now is that it began by grouping the digits in pairs. > Also this leads to the question as to whether Napier or Briggs were > able to find the value of log(2) or log(3) to 7 decimal places or did > that have to wait for Euler. Briggs published 14-place logs of the numbers from 1 to 20000 and 90000 to 100000 in 1624. Adrian Vlacq filled the gap in 1628 with a 10-place table. > After receiving my slide rule in the mail and trying a few > calculations, I have decided that weak eyesight precludes this method. As a teen I could read a slide rule easily, but now at age 52 it's impossible without help, though my distant vision is fine. A pair of reading glasses (+2.0 diopter) takes care of that problem. That's a little too strong a correction for viewing a computer monitor, but a slide rule is used at shorter distance. Sometimes I use a large, low power, hands free magnifying glass plus reading glasses. That extracts all the potential of the slide rule without eyestrain. The following 1872 article from the MNRAS mentions the Briggs and Vlacq tables. "With the exception of Vega's Thesaurus &c., the only complete table of ten figure logarithms that has been published is the original one, partially calculated by Briggs and completed by Vlacq... It is not a little remarkable that the most accessible table of ten-figure logarithms we possess should have been published nearly 250 years ago. This places their use out of the power of all who have not access to an important library." http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?journal=MNRAS&year=%3f%3f%3f%3f&volume=..32&letter=.&db_key=PRE&page_ind=255&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES I was surprised to find "Arithmetica Logarithmica" by Briggs (1624) on Google books. The original must be quite valuable. http://books.google.com/books?id=L88WAAAAQAAJ&dq=intitle:logarithmica+inauthor:briggs&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&as_brr=1&as_pt=ALLTYPES The seminal work by Napier is also on Google, in an 1889 English translation: http://books.google.com/books?id=Zlu4AAAAIAAJ&dq=intitle:logarithms&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&as_brr=1&as_pt=ALLTYPES There are a lot of logarithm and log trig tables on Google. Anyone who wants to reduce a sight the old fashioned way will have plenty of choices, though reading these tables over the web may be clumsy without a high speed connection. -- --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---