NARCISSE BRIAIS
letter scale

maker: Narcisse Briais, Paris, France bruine lijn

front of letter balance Narcisse Briais

This letter scale was made in France. The abbreviation N.B is engraved in letter plate and below this is the text DÉPOSÉ. The capital letters N.B. are the initials of Narcisse Briais from Paris. DÉPOSÉ means filed or deposited. It's not clear what this was for: protection of the logo N.B or protection of the design by a patent application. The patent of this letter balance was granted to Victor Briais and strangely not to Narcisse Briais.It has patent number 64178 and it was granted in 1864. On the counterweight arm of the balance are the opposite the weight in grams the postage due for letters in France. The patent and the majority of these letter balances found in publications state the postal rate valid for the period January 1, 1862 to January 1, 1871, with typically above 100 grams 1.60FF. On my copy is the postal rate that was valid in the period from January 1, 1871 to January 1, 1876, with characteristic above 100 grams 1.70FF and an additional rate limit at 50 grams. The letter balance purchased by me was unfortunately not complete. The counterweight and its suspension were gone, and only the mounting washer of the pointer was still present. With

back of letter balance

some measuring, calculating, and attempts to find the balance, and searching the internet, I found a brass sphere with by approximation the proper diameter and this results in a useful counterweight. I also made a replacement for the suspension. In order to obtain the correct zero position, with the balance exactly in equilibrium, it appeared necessary to add some brass underneath the counter-arm. I also made a pointer because there is one present in the patent drawing. On this letter balance the pointer is of little use. In Equilibrium 1992 No.1, on pages 1536-1537 a copy of this letter balance is presented that has an hexagon instead of a sphere as counterweight. I doubt the hexagon was originally made by Narcisse Briais.
Below some more pictures of this letter balance ating from the rather short postal period 1871-1876.

these patent drawings were taken from Le Système Métrique 1997
No. 97/3, page 1126 and were edited and cleaned up by me

the actual wooden base got a graceful shape

at the left: POIDS translated: WEIGHT, at the right: TAXE meaning:
RATE or POSTAGE DUE. Above 50 grams the rate per 50 grams
or a fraction thereof is 50 centimes. Above the 100 grams
the postal rate is 1.70 FF (up to 150 grams)

the scale of measure of
the French patent 64178
from 1864

The French postal rate from the period January 1, 1871 to January 1, 1876
is opposite the weight values.
0g-10g 25c, 10g-20g 40c, 20g-50g 70c, 50g-100g 1.20FF
and above 100g 1.70FF, this is valid up to 150g

animation: two positions
of the counterweight

animation: moving of the
counterweight

animation: the counterweight
move from 40 to 50 grams
resulting in a new equilibrium

the letter plate with the logo N.B and DÉPOSÉ	the transverse protruding suspension axis fits into the rate grooves	the transverse suspension axis rests in the zero groove of the rate scale
N.B logo and DÉPOSÉ in the letter plate	the central stand	gleaming in the light
from left side	of the right	reflections on wooden base
a slice of lead is under the brass letter plate	the pointer protrudes through a cutout of the frame	detail of sphere suspension
thrust pad protects the wood	in balance: the pointer is vertical	sphere hangs on the rate button
moving the counterweight	four simple round slices are the feet of the bottom	seen from above

« collection part 15 «

version: January 27, 2015

NARCISSE BRIAISletter scale

NARCISSE BRIAIS
letter scale