' ( 9 ^) 
Now the Situation of the three Cities London^ Oy- 
ford, and IVorcefter being nearly on the 
Point, whereon the Track of die Meteor had its grea* 
reft Altitude above the Horizon, equal to the Angle 
of its vifible Way; if we fuppofe it at London to have 
been 17 ^i*gh, and at the fame time at Worcefter 
to be 611 gr. high, in the Plane of the Vertical Circle 
palling through London and IVorcefier ; fuppofing like- 
wile the Dillance between them to be 90 Geographi- 
cal Miles, or one Degree and half of an Arch of a great 
Circle of the Earthy we lhall by a Trigonometrical 
Calculus, too obvious to be here inferred, find the per- 
pendicular Height to have been 64 fuch Miles ; and 
the Point over which it was then perpendicular to have 
been 30 fuch Miles W.N.W. from Worcefter. And the 
Geographical Mile to the EngUjh Statute Mile being as 
^3 to 20, this Height will be no lefs than 73 En^lilh 
Miles. The place alfo direoUy under it, will be found 
to be about Preftain on the Confines of Hereford and 
Radnor^hhkti. Nor can we be much out in this De- 
termination, the Oxford Obfervation concurring nearly 
in the fame Conclufion. 
This Altitude being added to the Semidiameter of 
the Earth as Radius, becomes the Secant of Eleven De- 
grees, fo that the Meteor might be feen above the Ho- 
rizon in all Places not more than 120 Leagues diflanc 
from it. Whence it will not be flrange that it fhould 
be feen over all Parts of the Iflands of Great Britain 
and Ireland, over all Holland and the hither Parts of 
German'^, France and Spain, at one and the lame inllant 
of Time. 
This fuggefts a very great ufe that might be made at 
thele momencaneous Vheenomena, to determine the Geogr^t^ 
fhtca' Longitudes of Maces. For if in any two Places two 
Obfervers, by help, of Pendulum Clocks duly coircfted 
by 
