Toise

The Toise [ twa ː s ( ə ) ], symbol T, is an old French unit of length. She was a normal unit of the old French measure length. The term is also used for the measuring scale of the unit.

History

From the 12th to the 19th century there was the Toise with regionally varying lengths and terms. From the 17th century the Toise of Paris played a significant role, driven by the large-scale scientific projects of that time.

Originally Toise was carlovingienne or Toise of maçons 1.9603 m long and corresponded to 6 pieds.

Toise du Grand Châtelet

She was admitted as an iron gauge in the staircase of the Grand Châtelet de Paris. Since the stage gave way with time and the iron damaged, 1668 a 5 lignes (Paris lines) shorter version was attached to the wall. She disappeared in 1755, presumably by theft.

This Toise had 6 old Paris feet = 864 Paris lines. Outside of the Louvre from the Rue Fromenteau out, late 18th century Inside, looking west on Sully pavilion, which was completed in 1654 under Louis XIV Design drawing of the Louvre from 1754 with Toise - scale There is conflicting evidence on the origin of the shorter version. A statement has been handed down from the third year after the theft and establishes a reference to the entrance of the Louvre:

" The standard was based on the half of the width of the inner Louvre door on the side of the Rue [ Fromenteau ]. "

Toise du Pérou

1735 was the Paris Academy of Sciences two dimensional standards of Toise make. Both iron rods were first French Geodesy and were manufactured with the claim to be exactly the same length. One of the two specimens was made ​​under the direction of Godin and the other in La Condamine, who were both members of the Académie. In both cases, the work was carried out by an instrument maker named Claude Langlois. Conflicting data exist for the production method:

" Langlois constructed- for the Académie du Pérou the Toise (a toise is 6 pieds de roi ) [.. And ] computed the pied de roi as the edge of the cube contains 70 did Paris livres of water. "

" Langlois presented for the Académie Toise you Pérou ago ( a Toise equivalent to 6 pieds de roi ) [.. And ] calculated the pied de roi than edge of the cube of 70 livres Paris contains water. "

" Langlois in 1735 [ ..] constructed- two copies of the Châtelet Toise [ ..] "

" Langlois 1735 [ ..] provided two copies of the Châtelet Toise ago [ ..] "

The Toise you Pérou was used from 1736 for degree measurements near the equator in what is now Ecuador, which were led by Bouger, La Condamine, and Godin. It was not until 1751 they came with Godin back to Paris, where it is kept until today.

The Toise du Nord went on a parallel scale expedition to the polnah located Lapland. There, too, the radii of curvature of adjacent latitudes were determined.

Toise de l' Académie

Since the Toise du Nord was damaged during the expedition, was the Toise you Pérou than the more accurate scale. On the basis of the latter led Louis XV. the Toise as a legal measure of length on May 16 in 1766. At the instigation of the Académie 80 copies of Toise you Pérou were made and distributed in the provinces. Thus, these Toise was also known as Toise de l' Académie de Paris or Toise. It replaced the Toise du Grand Châtelet from the default. The copies were made by Canivet, Langlois ' nephew, the 1756 took over the instrument after the death of his uncle.

The definitive standard meter was manufactured with a length that is exactly the ten millionth part of the earth's quadrant longitudinal in 1799 corresponded to how he had been determined by Delambre and Méchain.

On December 10, 1799, the length ratio between meters and Toise was redefined. But before the longitudinal extension of the definitive standard meter at 0 ° C was determined by experimental comparison with the longitudinal extent of Toise you Pérou at 16.25 ° Celsius. The results acquired for the legal definition amounted to 443.296 of the ablated on the Toise you Pérou lines:

The Toise de l' Académie is therefore 864000/443296 m = 27000/13853 ≈ 1.949 m 036 m long. At about 1888 this ratio is determined again and been reported:

" Newer Maßvergleichungen have shown that [= 16,25 ° C. ] is 1949.001 mm of the international meter at 13 ° R. The length of the standard 1949.093 mm, the bar dimension"

Bessel Toise

The Toise was still used in the 19th century by Bessel, the measurements of ten different, often previously occurred in the century projects the degree measurement mathematically compensated in order to obtain a better approximation for the earth's quadrant. He published his first results in 1837, but corrected it in 1841 because of changes in the results of the French degree measurement, which were relevant as input variables of its invoice. In the definition of EPSG: 2007 in certain approximation methods ellipsoid is led by 1841 with a point of inaccuracy, which refers to the lack of international standardization of Toise in the 18th century:

"Original Bessel definition is a = b = 3261139.33 3272077.14 and toise. This used a weighted mean of values ​​from several authors but did not account for differences in the length of the various toise: the " Bessel toise " is of uncertain THEREFORE length ".

"The original Bessel definition uses a = 3272077.14 and b = 3261139.33 Toise. This was calculated from the weighted average of [ degree measurement ] evaluate different [ international ] Creator, but did not count the differences between the various Toise lengths [ in the former circulation ] out. The length of the Bessel Toise is therefore indeterminable "

In fact, there Bessel in the Astronomische Nachrichten Volume 19 No 438 of 1842, the parameters a and b of the ellipse the meridian plane in [ Bessel ] Toise to the length of the earth's quadrant determined but in meters. Due to the time interval 1799-1842 can assume with some certainty that Bessel umrechnete exclusively with the definitive standard meter, so he gave the result of the earth's quadrant as a multiple of 443.296 lines on the Toise you Pérou at 16.25 ° Celsius. Since the Erdquadrant exactly a quarter of the total circumference of the ellipse indicates the calculation is required for its determination, and n, the flattening, no unit is present, a determination of a and b in meters should be possible only with these parameters. From this, the necessary factor in the resulting approximation method [ Bessel ] determine Toise for conversion into meters. The [ Bessel ] Toise can then be taken as a weighted average of the ten degree measurements occurring Toise different lengths.

Metric Toise

With the introduction of the metric system in 1812 by Napoleon as a transition from the old to the new system of units usuelle exactly 2 m long Toise or Toise métrique with 6 pieds usuels introduced. It was valid until January 1, 1840, in Haiti even longer.

The (metric ) Toise the French-speaking Switzerland had until 1876 six pieds and was exactly 1.80 meters long. In the Swiss canton of Neuchatel, there was the Toise who fathoms, for different areas from 1856. The underlying Landfuß here, Pied du pays, can be assumed to be 0.293258 meters or 130 Parisian lines. His disposition was duodecimal. It was one Landfuß to 0.97753 new Swiss foot and is not zuverwechseln with the Neuchâtel Feldfuß, Pied de champ, who was 0.287148 feet tall.

Source of Neuchâtel

In the 20th century there was in Quebec nor the Toise Quebecoise with 1.949 043 6 m length.

The Toise is similar to fathom, since it also often includes 6 feet.