Jean-Charles de Borda - Tables of Logarithms

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 degrees instead of 90 degrees, and the degree into 100 seconds instead of 60 seconds. This required the calculation of trigonometric tables and logarithms corresponding to the new size of the degree and instruments for measuring angles in the new system.

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 measurement of the meridian between Dunkirk and Barcelona by Delambre to determine 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 9 (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 and maps were required to show the new degrees of latitude and longitude. The Republican Calendar was abolished by Napoleon in 1806, but the 400-degree circle lived on as the Gradian.

Read more about this topic:  Jean-Charles De Borda

Famous quotes containing the words tables of and/or tables:

    O these encounterers, so glib of tongue,
    That give a coasting welcome ere it comes,
    And wide unclasp the tables of their thoughts
    To every ticklish reader! Set them down
    For sluttish spoils of opportunity
    And daughters of the game.
    William Shakespeare (1564–1616)

    It breedeth no small offence and scandal to see and consider upon the one part the curiosity and cost bestowed by all sorts of men upon their private houses; and on the other part the unclean and negligent order and spare keeping of the houses of prayer by permitting open decays and ruins of coverings of walls and windows, and by appointing unmeet and unseemly tables with foul cloths for the communion of the sacrament.
    Elizabeth I (1533–1603)