81
june 1670.
No meeting.
june 23. 70. The Curator produced a ^ /pocket/ watch of a new contriuance deui
sed
by himself. wch he affirmed should goe as equally as a pendu
lum,
and not stop/and/ w
thout stopping, and might be made
to goe 8. days.
The contriuance was this Tis an ordinary watch
wth an arbor of a ballance, hauing only one short arm, and no circle about it but hath a
large ballance placd about the midle of ths watch, in the inside of the limb whereof there is a notch S
r R Moray made a report
tht Iune 13. 70. he and Mr Hook
had made an Obseruation ^ /by
the North star/ to find, whether there were a differ
rence of
the present meridian from
tht, wch was formerly made
on the Dial in Whitehall garden.
He said that their Obseruati
on was made by the North starr in this manner. They ^ /The Observation/
they began to obserue /was made/ at 10
h. wanting 4
m l they hung on poles two perpen
[In margin]
l the sd starr
being was
to be high
East at 1h 1/4
dicular threds, wch couer'd one another and the Star, and
the South-East
side /edge/ of
the s
d Dial: the breadth of
the dial
vpon /from/
that side to the opposit was 4 feet 4 1/2 inches; and the plaine
between the two perpendicular threds was distant
from /at/ the
North East
side ^/edge/ of the dial, 3 inches wanting 1/20 part, wch
giues
the Angle of
the Poles distance East ward from the meridain
of
the dial. Here
the breadth of
the dial giues the Radius,
and the distance of
the Plain between the 2 perpendiculars giues
the /a/ Tangent. Then the difference between the dis
tance of
the Starr form the Pole, and the distance of the
plain between the perpendiculars from
the Dial side of
the
dial, giues
the tangent. Then the difference between the dis
tance of
the starr from the Pole, and the distance of the
plain between the perpendiculars from
the
Dial side of
the
dial, giues
the distance of
the dial from the meridian, if any
there be.
Mr Hooke hauing computed it, said,
tht
the by this Obserua
tion the meridian of
the Dial at Whiehal did differ
a whoone degree from the true meridian.
Whereupon A Whereupon it being considerd, that the meri+
dian of e s
d dial hauing been made by Mr Gunther w
th as much great exactnes, and hauing been hitherto esteemed
as an authentick one, the obseruation was to be repeated
Ref: CELL/RS/HF_083 © Centre for Editing Lives and Letters
