A\A Scientific Intelligence. 
The length of the meter is obtained between the heel-points, d, d@’, (or 
the extremities of the shorter arms df, d’f',) of two levers, de, d’e’, 
one lever at either extremity of the measure; the longer arms of which 
levers serve to multiply any minute differences of length in meters 
placed between the heel-points. The axes, ff’, upon which the levers 
move, are firmly fixed to the lower rule. The short arms, df, d'f’, 
are 8 millimeters long, and are curved. The long arms, fe, f’ e’, are 
160 mm. lon ese levers are placed vertically, above the rule to 
e 
The lever d’e’, (situated on the side a’, to the right in figure 2 
where the two rules are united together,) serves as a striker against one 
end of the meter under trial, the axis of rotation (/’) of this lever being 
the plate g hi, is measured by the micrometer screw, which is there- 
fore the measuring apparatus, properly so called. 
In order not to injure the extremities of the introduced meter, the 
two levers are held against these extremities only by means of a smal 
spring, 7, l’, the power of which does not exceed five grammes. 
=] 
o 
he 
zontal, 
At the summit m, m’, of the piece constituting the support of each 
ther on the top of the lever; 
to give still greater exactness to the observation, there is an rie aed 
to each support. If the small arms of the levers d, d’, are 1- | 
of a millimeter out of the way, it is indicated at the extremily of a 
long arm by half a division on the vernier, a quantity quite appreciab 
by means of the lenses. mee 
ith the 
the support. ‘This screw is situated in the prolongation of the uppe. 
sur on ae the platinu : lene 
reste) 22 Yahi 
The micrometric screw, s, above alluded to, makes just a sem a 
meter each revolution. The head ¢, is divided into 500 paris, — 
subdivided into 5000 by a vernier, (v) fixed to the support. a al. 
meter is thus graduated to 10,000 parts, which is equivalent to ; 
