Ancient Measurements => Lines

[Mark A. Garland]

On Wed, Oct 06, 2004 at 09:57:10PM +0000, Jacques Melot wrote:
>  Le 06-10-2004, à 14:46 -0400, nous recevions de christian thompson :

[snip]

> >If any one have better information or citations on lines as a unit of
> >measurement in taxonomy, I would appreciate them..

[another snip]

> P.-S.  Puisque vous êtes entomologiste, vous n'avez peut-être pas le
> livre de Stearn sous la main. Voici donc ce qu'écrit cet auteur :
>
>    Before the adoption of the metric system, devised in France at the
> end of the eighteenth century, authors used the traditional units
> based on the human body such as the foot (pes), the span (spithama),
> etc. Linnaeus's Philosophia botanica, 262, no. 331 (1751) provides a
> convenient summary :
>
> CAPILLUS (i.e. a hair's width) = Lineae pars duodecima = 1/12 Paris
> line = 0.18 mm.
>
> LINEA = Linea una Mensurae parisinae = 2.25 mm.
>
> UNGUIS (i.e. the length of a finger-nail) = Lineae sex sive uncia
> dimidia = 6 lines = 1.35 cm = 1/2 inch (approx.)
>
> POLLEX (i.e. the length of the terminal joint of the thumb) = Uncia
> una parisina = 1 Paris inch = 12 lines = 2.7 cm = 1 1/12 inch
> (approx.)

In the original Latin, Linnaeus also defines a line as the length of a
lunule (the white part at the base of a fingernail) extended from the
root of the fingernail towards the [tip of the] nail (but not on a
thumb).  See http://botanicallatin.org/philbot/pb331.html.  I don't
seem to have any lunules, so for me 1 line = 0 mm.

In the same work, Linnaeus has a drawing of three Parisian inches,
three English inches, and three Swedish inches
(http://botanicallatin.org/philbot/pbtbx.html).  In my copy, his 3
Parisian inches as printed are 81 mm long.  So 1 Parisian inch = 27 mm
and 1 line (1/12 inch) = 2.25 mm, as Stearn says.  His 3 English
inches = 75 mm, so 1 English inch = 25 mm and 1 (English?) line =
2.083 mm.  His 3 Swedish inches = 73 mm, so 1 Swedish inch = 24.333 mm
and 1 (Swedish?) line = 2.028 mm.

Those are measurements straight from a 1770 edition of the Philosophia
Botanica.  You should allow for errors in printing, I suppose.  But it
seems you can't go wrong with Linnaeus if you say a line is about 2
mm.

--
Mark A. Garland
1016 NE 12th Avenue
Gainesville, Florida 32601
U.S.A.