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greateft obfcuration, or ends, with the rifing or fetting 
nm. 
7. A handle, which, by wheel-work, turns the 
globe round its axis, and at the fame time, by a thread 
and pullies, carries the penumbra over its furface with 
a velocity proportional to that of the moon’s fhadow 
over the earth; which being quicker or flower, ac- 
cording to the different diftances of the moon from 
the earth, is eafily regulated, in the machine, by 
changing one of the pullies. 
To redilfy the machine for ufe. 
The true time of new moon, and her latitude at 
that time, muff be firft known. If her latitude ex- 
ceeds the number of minutes on the fcales, there can 
be no eelipfe of the fun at that conjunction ; but if it 
does not, the fun will be eclipfed to fome places of 
the earth : And to fhew the times and various ap- 
pearances of the eelipfe, at thofe places, proceed in 
order, as follows : 
If you reCtify for performing by the light of the 
fun; 1. Move the Aiders till their indices point to 
the moon’s latitude on the fcales, as it is at that time 
north or fouth, afeending or defeending. 2. Turn 
the month-plate till the day of new moon comes to 
the annual index. 3. Unfcrew the collar on the axis 
of the handle, and fet the penumbra, by hand, till 
its centre comes to the perpendicular thread in the 
middle of the frame. 4. Turn the handle till the 
meridian of London, on the globe, comes juft under 
the point of the crooked wire ; flop there, and turn 
the hour-circle, by hand, till XII. at noon comes to 
2 its 
