The sun., 1919-09-21
New Units of Measure

grees), under normal atmosphere
pressure. The normal atmospheric
pressure is represented by the pres.
sure of a column of mercury $50
millimetres high, having a density Of
1,359,593, and submitted to a norma
intensity of a weight measured by an
acceleration equal to 9S0665 in metres
and seconds.
The thermie is the unit OF heat
This is the quantity of heat necessary
to raise to one degree centesimal the
temperature of a mass of one ton Of a
body, whose specific heat is equal to
that of water at is degrees, under
pressure of lob hectopieze-equiva.
lent TO the normal atmospheric pres
sure represented. The designations,
great and little calorie may be given,
respectively, to the mlHttherHtts,
1-1,000th, and to the m!crothermle,
$1,000, 000th. In refrigerating and Ice
industries the quantity of heat con
stunned may be valued in trigories
The triOorie, in absolute value, will be
the equal of the milHthermie.
Optical units are enumerated and
defined. The decimal candle is repre-.
scented by a fraction determined by
means of average intensities OF at
least five standard incandeScent lamps
deposited for that purpose with the
National Conservatory Of Arts and
Handicrafts, measurements being
made perpendicularly from the axis
of the lamps.
The lumen is the luminous nov
emanated from source uniform IN
infinitely small dimensions and Of an
intensity equal to one decimal candle
and radiated in one second, within
solid angle which describes an area
equal to one square meter on the orb
of one metre of ray, having for the
centre the source.
Units of Lighting Power
The decree is concerned with the
units of lighting power. The lux
The lighting power from a surface OF
one square metre receiving now OF
one lumen, uniformly distributed
"One may also use as a unit OF hsh''
ing power the pilot. which Is inc
lighting power from a surface OF ons
square centimetre receiving a flow OF
one lumen uniformly distributed.
pilot is composed of 10000 lux. ms
power of optical systems is expressed
in dioptries by their inverse Foca
distance, given in metres.
For temporary title, the emploE'
ment and denomination of Geomeu4'
cal and mechanical units az present
in use is authorized by the decree.
OF geometric units. the sea mile IS az
fined as having the conventional Nalus
of 1852 metres, corresponding 10 VI,
distance from two points OF lana %
the same longitude and whose lsu'
tuds differs one minute. ne seo
mile elucidates the decree - Wv
distance travelled I'm an hour ny
merchant ship at speed Of o"'
knot"
In measuring MECHANICAL units INV
kilogram weight or force is dehneo a.
the force by which a mass equa'
one kilogram is attracted by the e's
This unit is practically equal TO u"
centisthene. The kilogrammetre' W.
unit of mechanical energy NV
work produced by A kilosrsm Io,.'
whose point Of application Is us
placed a metre in the direction oil u,
force, and is practically equal 10 ''
joules. Il
The horsepower corresponds "
kilogrammetres per second; the pon0s
let corresponds to 100 Kilograms ~
second. The horse power unit anu Wv
ponceIet are practically equai
spectiveIy. to O.7S5 and OBS hilo"aus
In measuring mechanical pressu..
the kilogram force per square n,s
is the pressure practically equS'
0.9S hectopieze, nd
For France, the French colonies ai
the French protectorate countries W.
lawful standards OF the metre ana "a
kilogram are "the copy II degrees
of the international metre ana VI ~
copy n degrees IS of the intefna''ons,
kilogram deposited with the Na''oIh
Conservatory of Arts ana i'''1'
crafts"
Preservation of standards OF P'"
cipsl and secondary units Will
subject of ministerial order ""'..
will al.o determine the rules 20 F"
observed.