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© The Royal Society

401

1676
Dec 19. hor

h I II m
8 09 00 the Morneing the Suns following limbe was
in the same Azimuth with Eltham Steeple.
His true Azimuth from the Meridian . at
this time by Calculation found 51o.15' East .
= to the Angle EOM
The Angle Subtended betwixt Eltham Steeple
and the Windmil at Bromley . at the Obser-
=uatory on Saturday last 48o.15 3/4 = EOB
Therefore the Azimuth of Bromley Windmil B.
from the Meridian Eastwards B O M . 3o. 00'.
But the Azimuth of Bromley Windmill from
the Magneticall Meridian . taken yesterday
was one degree or at most 1 1/4 gr. to the West
=wards = B O M
Therefore the variation M O m. 4o. 00' or at most
4 1/4 degrees . Westerly in the North . to the East
in the South partte of the compasses . by the
Equilibrated needle one foot long
ffebruary . 25 1679/80 in
the Obseruatory at
Greenwich: by I fflamsteed:

Ref: CELL/RS/HF_403  © Centre for Editing Lives and Letters