398 An Account oj the Measurement 
placed above it. The means of making the interior stand ver- 
tical, are found in the work annexed to the azimuth circle. 
They consist of two screws, attached to two plates of brass, 
placed at right angles to, and also flat on each other. S s (Plate 
XIV.) are the screws. A vernier on the divided circle may be 
seen at S ; and at s , the method of clamping the bottom of the 
stand. On the opposite side is another provision for clamping 
this stand, when the face of the sector is changed from east to 
west, or vice versa. 
KLMNO/> ( Plate X.) is a section of the telescope and axis, 
MR, MR, being two of the four braces for strengthening the 
axis, and steadying the telescope. K is the place of the eye- 
tube ; L the elliptical reflector for illuminating the wires at K ; 
and ON a hollow cylinder of brass, independent of the tube. In 
the upper part of this cylinder, the object-glass is rivetted ; the 
cylinder itself being fastened to the great eye-tube, in a perma- 
nent manner. 
W, W, are two weights* hanging freely from the ends of two 
levers, the opposite ends being furnished with four friction- 
wheels. The points of support, between the weights and wheels, 
are at TT, being at the extremities of two upright solid pieces 
of metal, which are moved up or down by the screws beneath 
them. These counterpoising weights prevent any bending of the 
axis, between the pivots and those parts to which they apply. 
The apparatus for carrying the levers, is attached to the inside 
mahogany frame by screws, as represented in the section. See 
also Plate XIII. 
The plummet and • plumb-line are seen at aed; the point of 
suspension being#, and the plummet d; the plumb-line passing 
close by the arch, whose section is he, and also near to the dot 
