Jump to content
Main menu
Main menu
move to sidebar
hide
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Special pages
Niidae Wiki
Search
Search
Appearance
Create account
Log in
Personal tools
Create account
Log in
Pages for logged out editors
learn more
Contributions
Talk
Editing
Jean-Charles de Borda
(section)
Page
Discussion
English
Read
Edit
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
View history
General
What links here
Related changes
Page information
Appearance
move to sidebar
hide
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==Tables of logarithms== With the advent of the metric system, after the French Revolution it was decided that the [[quarter circle]] should be divided into 100 [[angular units]], currently known as the ''[[gradian]]'', instead of 90 [[degrees (angle)|degrees]], and the gradian into 100 centesimal minutes of arc ([[centigrade (angle)|centigrades]]) instead of 60 [[arc-minutes]].<ref name="Klein 2012 p. 114">{{cite book | last=Klein | first=H.A. | title=The Science of Measurement: A Historical Survey | publisher=Dover Publications | series=Dover Books on Mathematics | year=2012 | isbn=978-0-486-14497-9 | url=https://books.google.com/books?id=CrmuSiCFyikC&pg=PA114 | access-date=2022-01-02 | page=114}}</ref> This required the calculation of trigonometric tables and logarithms corresponding to the new unit and instruments for measuring angles in the new system.<ref>''Tables Trigonométriques Décimales ou Table des Logaritihmes des Sinus, Sécantes et Tangentes, Suivant la Divisiondu Quart de Cercle en 100 degrés, du Degré en 100 Minutes, et de la Minute en 100 Secondes'' revues, augmentées et publiées par J. B. Delambre, Paris, AN IX (1801), L'Imprimerie de la République</ref> Borda constructed instruments for measuring angles in the new units (the instrument could no longer be called a "sextant") which was later used in the [[arc measurement]] of the meridian between Dunkirk and Barcelona by Delambre to determine the radius of the Earth and thus define the length of the metre. The tables of logarithms of sines, secants, and tangents were also required for the purposes of navigation. Borda was an enthusiast for the metric system and constructed tables of these logarithms starting in 1792 but their publication was delayed until after his death and only published in the Year IX (1801) as ''Tables of Logarithms of sines, secants, and tangents, co-secants, co-sines, and co-tangents for the Quarter of the Circle divided into 100 degrees, the degree into 100 minutes, and the minute into 100 seconds'' to ten decimals, and including his tables of logarithms to 7 decimals from 10,000 to 100,000 with tables for obtaining results to 10 decimals. The division of the degree into hundredths was accompanied by the division of the day into 10 hours of 100 minutes ([[decimal time]]) and maps were required to show the new degrees of latitude and longitude. The [[French Republican Calendar|Republican Calendar]] was abolished by Napoleon in 1806, but the 400-unit circle lived on as the [[Gradian]].
Summary:
Please note that all contributions to Niidae Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Encyclopedia:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Search
Search
Editing
Jean-Charles de Borda
(section)
Add topic