Dearborn’s gold standard Balance. 45 
each side, leaving in the centre a space of six inches for the motion 
of the index, which extends downward from the beam. In this 
space a lever is fixed for raising the beam with the scales and their 
load. One end of this lever is raised, and supported when up, by a 
bended lever and friction-wheel, the weight of the beam &c. pressing 
on the centre of the first mentioned lever. The pedestals and capitals 
of the columns are conformable to the Tuscan order of architecture, 
and on the top of each pair is a brass plate screwed down by rods, 
passing through the columns to the lower surface of the base. From 
one of these plates to the other two semicircular brass arches ex- 
‘enacourt, with a proper distance between them for the beam. & 
the internal surface of each of these arches a perpendicular dove-tail 
grooye is made, to guide the top of the parallel, by which the beam 
is supported. This parallel consists of two similar parts, each of 
which is formed by two rods of iron, unjted at top and bottom, 
opening in the centre, and extending from the arches nearly to the 
asi cig ‘sdhiabes steel is welded on the upper extremity, which; is 
ollowed into an arch of a large circle, well tempered and polished ; 
pep ernie of each part is riveted into an iron plate, at a distance 
apart equal to the distance of the brass arches aboye; in the centre 
seeping ge Beene ne 29 downward to the lever, on 
ak ais am The axis of the beam rests in the 
hollow at the top of the parallel, and its sharp edge is the only part, 
which comes in contact we ete, ports, a eo ae 
‘This is effected by_p 
1, tha awsec sof the | ‘tom ri aie 
oh De ae = 
~ TS ee eee 
. 7 eines thin ineatbonY: 
“ F = a oe ic oi cieell ta aed = oO Be a 4 dite <li’ oO at vs 
2 2D wie see “a rae a ee sh ae. 
