340 An Astronomical Machine, the Tellurium. 
situated in one of its foci. The axis of the wheel L also carries 
a large circular wheel M ; next to which is placed a pinion N, 
upon the upper end of whose axis the winch 7 is fixed. Qisa 
stout metallic axis of the same size as that which carries the 
wheel K. These two axes pass perpendicularly through the 
boards 1 and 3, the upper part of each axis where it comes 
through the board 1 being situated in one of the foci of one of 
the elliptical grooves. Upon the upper ends of these axes two 
arms # and 7 are tightly fixed. Two other arms R and S are 
fixed upon their lower ends so as to be perpendicular to A and 7. 
'T is a narrow metallic plate which is connected with the arms R 
and $ by two movable joints: this plate assists in regulating the 
motion of the machine. Into the arms / and 2, are inserted two 
axes f and g, which pass up through a movable frame 5 67 8 and 
turn freely within it. The lower ends of these axes project into 
the elliptical grooves in the board 1 and slide along these grooves 
when the machine is in motion, the arms # and 7 being so con- 
trived as either to lengthen or shorten according as the distance 
of the groove from its focus increases or diminishes. 
‘The movable frame 5 67 8 contains a number of wheels, Which 
serve to rotate the earth on its axis and give motion to the moon, 
its nodes and apogee. A metallic supporter Y has inserted into 
it a long and narrow socket, which passes up through a hole in 
the plate Z. Upon the upper end of this socket a small brass 
arm a is fixed, which holds a pinion 0, whose axis forms an angle 
of 234 ee & with the perpendicular, and carries the earth U. 
C is a pinion whose axis passes up through this socket and is sur- 
mounted by a very small wheel whose teeth act upon the leaves 
of the pinion 0. D, F, and H, are three wheels, each of which 
is fixed upon a separate socket. The socket of the wheel D 
turns upon the socket which is fastened into the supporter Y- 
The socket of F turns upon the socket of D; and the socket of 
H turns upon that of the wheel F. Upon the upper end of the 
socket of Da small circular brass plate ¢ is fixed, into which, 
near its edge, is inserted a small flattened socket, through which 
passes a flattened wire which carries the moon V. The lower 
end of this wire rests on another circular plate d, which is fixed 
upon the socket of the wheel F and has an oblique position, 
forming an angle of 5 degrees with a horizontal plane passing 
through its centre. This wire is kept constantly applied to the 
